Combining phosphor light with spectrally overlapping eye-safe laser light

Abstract

The invention provides a light generating system (1000) comprising a first light generating device (110), a second light generating device (120), a luminescent material element (2000), and optics (500): the first light generating device (110) is configured to generate first device light (111); the luminescent material element (2000) comprises a luminescent material (200); wherein the luminescent material (200) is configured to convert at least part of the first device light (111) received by the luminescent material element (2000) into luminescent material light (201); wherein in at least part of a first luminescence wavelength range (λLR1) and in at least part of a second luminescence wavelength range (λLR2) the luminescent material light (201) has spectral power; the second light generating device (120) is configured to generate second device light (121); and the optics (500) comprise redirection elements (510,520,530). With such it is possible to combine beams of spectrally different types of light while minimizing loss of spectral intensity in overlapping spectral ranges.

Description

[0001] 2024PF80214

[0002] 1

[0003] COMBINING PHOSPHOR LIGHT WITH SPECTRALLY OVERLAPPING EYE-SAFE

[0004] LASER LIGHT

[0005] FIELD OF THE INVENTION

[0006] The invention relates to a light generating system as well as to a lighting device comprising such a light generating system.

[0007] BACKGROUND OF THE INVENTION

[0008] The use of dichroic beam combiners is known in the art. For instance, US2020158312, describes a light source module comprising: a plurality of light sources, wherein at least two of the light sources are of different types; one or more mirrors for combining light emitted from each of the light sources into a combined light beam; and an output connector for transmitting the combined light beam to a fiber optic cable, wherein: the plurality of light sources includes at least a first light source and a second light source; the one or more mirrors include at least a dichroic mirror having a rear-facing side and a front-facing side; the first light source, the second light source, and the dichroic mirror are positioned relative to each other such that a first beam of light originating from the first light source enters the rear-facing side of the dichroic mirror and passes through the dichroic mirror exiting on the front-facing side of the dichroic mirror; and a second beam of light from the second light source is reflected from the front-facing side of the dichroic mirror in a same direction that the first beam of light exists the front-facing side of the dichroic mirror; whereby the first beam of light and the second beam of light are overlaid and combined into a single beam.

[0009] US2023 / 042488A1 discloses a light source device having a first light source section that emits light in a first wavelength region and a wavelength conversion section that is excited by the light in the first wavelength region to emit light in a second wavelength region. A polarization separation element is disposed between the first light source section and the wavelength conversion section that separates incident light on the basis of polarization, and a color separation element is disposed between the first light source section and the polarization separation element that separates incident light on the basis of a wavelength region. 2024PF80214

[0010] 2

[0011] US9249949B2 discloses a lighting device having a phosphor wheel, a colorcombining prism including dichroic surfaces wherein the film surfaces of these dichroic surfaces are being disposed to cross a center ray of luminous flux of fluorescence emitted from the phosphor wheel and to be orthogonal to a plane that contains the center ray. The device further has a blue laser, a red laser and excitation light sources. When viewed from the direction perpendicular to the plane, the blue laser, red laser, and excitation light sources are arranged on one side of the center ray of the luminous flux of the fluorescence.

[0012] US2021 / 286246A1 discloses a light-source system comprising an excitation light source, first supplementary light source, first light-guiding assembly, wavelength conversion apparatus, and second light-guiding assembly. The first light-guiding assembly is for guiding excitation light to the wavelength conversion apparatus. The wavelength conversion apparatus provides excited light that is irradiated onto the first light-guiding assembly. The first light-guiding assembly is for guiding excited light to irradiate onto the second light-guiding assembly. The second light-guiding assembly is for guiding the excited light and / or the first supplementary light, such that the first supplementary light and at least part of the excited light are output from same emission channel.

[0013] US2019 / 391477A1 discloses a light source apparatus that includes a blue laser light emitter, a red laser light emitter, a phosphor that produces yellow fluorescence, a first optical element that combines the yellow fluorescence with a second component of the blue laser light to produce first combined light containing a red component, a green component, and a blue component. The apparatus further has a second optical element that reflects the red laser light, transmits a first polarized component in the red component, reflects a second polarized component in the red component, transmits the green component and the blue component, and combines the red laser light, the first polarized component, the green component, and the blue component with one another to produce second combined light. A retardation film is provided at a downstream side of the second optical element, and a third optical element is present that combines part of third combined light with the second polarized component to produce illumination light.

[0014] US2022 / 026788A1 discloses an illumination device that includes a first light emitting element emitting first light in a first wavelength band, a wavelength conversion element converting a part of the first light into second light including a second wavelength band and a third wavelength band, and diffusing another part of the first light. The device further has a second light emitting element for emitting third light having the second wavelength band. A first optical element is present and having a first area for reflecting the 2024PF80214

[0015] 3 first light to enter the wavelength conversion element, reflecting fourth light having the second wavelength band out of the second light, and reflecting the third light, and a second area for transmitting the first light and the second light. A second optical element is present for transmitting the first light to enter the first optical element and reflecting the fourth light to enter the wavelength conversion element via the first area.

[0016] SUMMARY OF THE INVENTION

[0017] For using a dichroic mirror to combine beams of spectrally different types of light, it may be desirable that the spectrally different types of light do essentially not spectrally overlap. In such way, the cut-off wavelength of the dichroic mirror (dichroic beam combiner) may be chosen between the respective spectral power distributions. Would however there be spectral overlap between the spectrally different types of light, then combination with a dichroic beam combiner may lead to loss of part of the light of at least one of the spectrally different types of light.

[0018] Hence, it is an aspect of the invention to provide an alternative light generating system wherein beams of spectrally different types of light can be combined, which preferably further at least partly obviates one or more of above-described drawbacks. The present invention may have as object to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.

[0019] According to a first aspect, the invention provides a light generating system (“system”) comprising a first light generating device, a second light generating device, a luminescent material element, optics, and a light exit. Especially, the first light generating device may be configured to generate first device light. In embodiments, the first device light may have a first peak wavelength (kpl ) selected from the wavelength range of 380-490 nm. Especially, the first light generating device may comprise a solid-state light source selected from the group of laser diodes, superluminescent diodes, and multi -junction diodes. Further, in embodiments the luminescent material element may comprise a luminescent material. Yet, in embodiments the luminescent material may be configured to convert at least part of the first device light received by the luminescent material element into luminescent material light. In embodiments, in at least part of a first luminescence wavelength range (ZLR1) and in at least part of a second luminescence wavelength range (ZLR2) the luminescent material light may have (non-zero) spectral power. Especially, the second light generating device may be configured to generate second device light. In embodiments, in at least part of a second device light wavelength range (ZDR2) the second device light may have (non-zero) spectral 2024PF80214

[0020] 4 power. In embodiments, the second light generating device may comprise a solid-state light source selected from the group of laser diodes, superluminescent diodes, and multi -junction diodes. In embodiments, the optics may comprise redirection elements. In specific embodiments, a first redirection element and a third redirection element may be configured in an optical path between the first light generating device and the luminescent material element. Further, in embodiments the first redirection element may be configured to direct (such as transmit) at least part of the first device light received by the first redirection element to the luminescent material element via the third redirection element. Especially, in embodiments the third redirection element may be (a) transmissive for first device light, received by the third redirection element, (b) transmissive for luminescent material light having a wavelength in the first luminescence wavelength range (XLR1), received by the third redirection element, (c) transmissive for luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) comprising a first linear polarization, received by the third redirection element, and (d) reflective for luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) and comprising a second linear polarization, different from the first linear polarization, received by the third redirection element. Hence, the third redirection element may be a third polarization based redirection element. Further, in specific embodiments the optics (comprising the third polarization based redirection element) may be configured such that at least part of the luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) and comprising the second linear polarization may be directed back to the luminescent material element. Yet, in specific embodiments the first redirection element may be configured to direct (at least part of) (a) luminescent material light having a wavelength in the first luminescence wavelength range (ZLR1), and (b) luminescent material light having a wavelength in the second luminescence wavelength range (ZLR2) and comprising the first linear polarization, received by the first redirection element, in an optical path to the light exit, via a second redirection element. Especially, in embodiments the second redirection element may be configured to direct (at least part of) (a) luminescent material light having a wavelength in the first luminescence wavelength range (ZLR1) (received via the first redirection element), (b) luminescent material light having a wavelength in the second luminescence wavelength range (ZLR2) and comprising the first linear polarization (received via the first redirection element), and (c) second device light (comprising the second linear polarization), received by the second redirection element, into an optical path to the light exit. Further, in embodiments the light generating system may be configured to generate system 2024PF80214

[0021] 5 light comprising (in an operational mode of the light generating system) one or more of (a) at least part of the luminescent material light having a wavelength in the first luminescence wavelength range (XLR1), (b) at least part of the luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) and comprising the first linear polarization, and (c) at least part of the second device light (comprising the second linear polarization). In such embodiments, the second device light reaching the second redirection element to be directed in an optical path to the light exit, may comprise a second polarization. Further, in specific embodiments the light generating system may comprise a diffuser arrangement, configured to diffuse the second device light. In such embodiments, the second device light reaching the second redirection element to be directed in an optical path to the diffuser arrangement, may comprise a first polarization, whereas the diffused second device light (diffused by the diffuser arrangement) reaching the second redirection element to be directed in an optical path to the light exit, may comprise a second polarization. Hence, in embodiments (with respect to the second light generating device,) the diffuser arrangement may be configured (both) downstream of the second redirection element (for second device light comprising the first polarization) and upstream of the second redirection element (for second device light comprising the second polarization), wherein the diffuser arrangement may especially be configured in a reflective mode. According to a further aspect, the invention provides a light generating system (“system”) comprising a first light generating device, a second light generating device, a luminescent material element, and optics. Further, the system may comprise a light exit. Especially, the first light generating device may be configured to generate first device light. In embodiments, the first device light may have a first peak wavelength (kpl) selected from the wavelength range of 300-490 nm, such as selected from the wavelength range of 380-490 nm. Further, in specific embodiments the first light generating device may comprise a solid-state light source selected from the group of diode lasers, superluminescent diodes, and multi -junction diodes. Further, especially the luminescent material element may comprise a luminescent material. In embodiments, the luminescent material may be configured to convert at least part of the first device light received by the luminescent material element into luminescent material light. In embodiments, in at least part of a first luminescence wavelength range (ZLR1) and in at least part of a second luminescence wavelength range (ZLR2) the luminescent material light may have (non-zero) spectral power. Further, especially, the second light generating device may be configured to generate second device light. In embodiments, in at least part of a second device light wavelength range (ZDR2) the second device light may have (non-zero) spectral 2024PF80214

[0022] 6 power. Further, in specific embodiments the second light generating device may comprise a solid-state light source selected from the group of diode lasers, superluminescent diodes, and multi -junction diodes. In embodiments, the optics may comprise redirection elements, and a diffuser arrangement. Yet, in embodiments a first redirection element (selected from the redirection elements) and a third redirection element (selected from the redirection elements) may be configured in an optical path between the first light generating device and the luminescent material element. Further, in embodiments, the first redirection element may be configured to direct (such as transmit) at least part of the first device light received by the first redirection element to the luminescent material element via the third redirection element. In specific embodiments, the third redirection element may be one or more of (a) transmissive for first device light, received by the third redirection element, (b) transmissive for luminescent material light having a wavelength in the first luminescence wavelength range (XLR1), received by the third redirection element, (c) transmissive for luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) comprising a first linear polarization, received by the third redirection element, and (d) reflective for luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) and comprising a second linear polarization, different from the first linear polarization, received by the third redirection element. In embodiments, the optics (especially comprising the third (polarization based) redirection element) may be configured such that at least part of the luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) and comprising the second linear polarization may be directed back to the luminescent material element. Furthermore, in embodiments, the first redirection element may be configured to direct (at least part of) one or more of (a) luminescent material light having a wavelength in the first luminescence wavelength range (XLR1), and (b) luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) and comprising the first linear polarization, received by the first redirection element, in an optical path to the light exit, via a second redirection element. Especially, in embodiments the diffuser arrangement may comprise a retarder element and a polarization maintaining diffuser. In specific embodiments, the retarder element may comprise a / 4 plate. Further, in embodiments the second redirection element (selected from the redirection elements) and the retarder element may be configured in an optical path between the second light generating device and the polarization maintaining diffuser. Yet, in embodiments the light generating system may be configured such that second device light received by the second redirection element may comprise the first linear polarization. 2024PF80214

[0023] 7

[0024] Further, in embodiments the second redirection element may be configured to direct second device light comprising the first linear polarization, received by the second redirection element, in an optical path to the diffuser arrangement. In further embodiments, the diffuser arrangement may be configured to convert second device light comprising the first linear polarization, received by the diffuser arrangement, into diffused second device light comprising the second linear polarization. Furthermore, in embodiments the second redirection element may be configured to direct (at least part of) one or more of (a) luminescent material light having a wavelength in the first luminescence wavelength range (XLR1) (received via the first redirection element), (b) luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) and comprising the first linear polarization (received via the first redirection element), and (c) diffused second device light comprising the second linear polarization, received by the second redirection element, into an optical path to the light exit. Yet, in embodiments the light generating system may be configured to generate system light comprising (in an operational mode of the light generating system) one or more of (a) at least part of the luminescent material light having a wavelength in the first luminescence wavelength range (XLR1), (b) at least part of the luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) and comprising the first linear polarization, and (c) at least part of the diffused second device light comprising the second linear polarization. Hence, in embodiments, the invention provides a light generating system comprising a first light generating device, a second light generating device, a luminescent material element, optics, and a light exit, wherein: (A) the first light generating device is configured to generate first device light; wherein the first device light has a first peak wavelength (kp l ) selected from the wavelength range of 380-490 nm; wherein the first light generating device comprises a solid-state light source selected from the group of laser diodes, superluminescent diodes, and multi -junction diodes; (B) the luminescent material element comprises a luminescent material; wherein the luminescent material is configured to convert at least part of the first device light received by the luminescent material element into luminescent material light; wherein in at least part of a first luminescence wavelength range (ZLR1) and in at least part of a second luminescence wavelength range (ZLR2) the luminescent material light has (non-zero) spectral power; (C) the second light generating device is configured to generate second device light; wherein in at least part of a second device light wavelength range (ZDR2) the second device light has (nonzero) spectral power; wherein the second light generating device comprises a solid-state light source selected from the group of laser diodes, superluminescent diodes, and multi -junction 2024PF80214

[0025] 8 diodes; (D) the optics comprise redirection elements; (E) a first redirection element and a third redirection element are configured in an optical path between the first light generating device and the luminescent material element; (F) the first redirection element is configured to direct (such as transmit) at least part of the first device light received by the first redirection element to the luminescent material element via the third redirection element; (G) the third redirection element is (a) transmissive for first device light, received by the third redirection element, (b) transmissive for luminescent material light having a wavelength in the first luminescence wavelength range (XLR1), received by the third redirection element, (c) transmissive for luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) comprising a first linear polarization, received by the third redirection element, and (d) reflective for luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) and comprising a second linear polarization, different from the first linear polarization, received by the third redirection element; (H) the optics (comprising the third (polarization based) redirection element) are configured such that at least part of the luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) and comprising the second linear polarization is directed back to the luminescent material element; (I) the first redirection element is configured to direct (a) luminescent material light having a wavelength in the first luminescence wavelength range (ZLR1), and (b) luminescent material light having a wavelength in the second luminescence wavelength range (ZLR2) and comprising the first linear polarization, received by the first redirection element, in an optical path to the light exit, via a second redirection element; (J) the second redirection element is configured to direct (a) luminescent material light having a wavelength in the first luminescence wavelength range (ZLR1) (received via the first redirection element), (b) luminescent material light having a wavelength in the second luminescence wavelength range (ZLR2) and comprising the first linear polarization (received via the first redirection element), and (c) second device light (comprising the second linear polarization), received by the second redirection element, into an optical path to the light exit; and (K) the light generating system is configured to generate system light comprising (in an operational mode of the light generating system,) one or more of (a) at least part of the luminescent material light having a wavelength in the first luminescence wavelength range (ZLR1), (b) at least part of the luminescent material light having a wavelength in the second luminescence wavelength range (ZLR2) and comprising the first linear polarization, and (c) at least part of the second device light (comprising the second linear polarization). Hence, in yet further embodiments the 2024PF80214

[0026] 9 invention provides a light generating system comprising a first light generating device, a second light generating device, a luminescent material element, optics, and a light exit, wherein: (A) the first light generating device is configured to generate first device light; wherein the first device light has a first peak wavelength (kpl ) selected from the wavelength range of 380-490 nm; wherein the first light generating device comprises a solid-state light source selected from the group of diode lasers, superluminescent diodes, and multi -junction diodes; (B) the luminescent material element comprises a luminescent material; wherein the luminescent material is configured to convert at least part of the first device light received by the luminescent material element into luminescent material light; wherein in at least part of a first luminescence wavelength range (ZLR1) and in at least part of a second luminescence wavelength range (ZLR2) the luminescent material light has (non-zero) spectral power; (C) the second light generating device is configured to generate second device light; wherein in at least part of a second device light wavelength range (ZDR2) the second device light has (nonzero) spectral power; wherein the second light generating device comprises a solid-state light source selected from the group of diode lasers, superluminescent diodes, and multi -junction diodes; (D) the optics comprise redirection elements, and a diffuser arrangement; (E) a first redirection element and a third redirection element are configured in an optical path between the first light generating device and the luminescent material element; (F) the first redirection element is configured to direct (such as transmit) at least part of the first device light received by the first redirection element to the luminescent material element via the third redirection element; (G) the third redirection element is (a) transmissive for first device light, received by the third redirection element, (b) transmissive for luminescent material light having a wavelength in the first luminescence wavelength range (ZLR1), received by the third redirection element, (c) transmissive for luminescent material light having a wavelength in the second luminescence wavelength range (ZLR2) comprising a first linear polarization, received by the third redirection element, and (d) reflective for luminescent material light having a wavelength in the second luminescence wavelength range (ZLR2) and comprising a second linear polarization, different from the first linear polarization, received by the third redirection element; (H) the optics (comprising the third (polarization based) redirection element) are configured such that at least part of the luminescent material light having a wavelength in the second luminescence wavelength range (ZLR2) and comprising the second linear polarization is directed back to the luminescent material element; (I) the first redirection element is configured to direct (a) luminescent material light having a wavelength in the first luminescence wavelength range (ZLR1), and (b) luminescent material light having 2024PF80214

[0027] 10 a wavelength in the second luminescence wavelength range (XLR2) and comprising the first linear polarization, received by the first redirection element, in an optical path to the light exit, via a second redirection element; (J) the diffuser arrangement comprises a retarder element and a polarization maintaining diffuser; wherein the retarder element comprises a X / 4 plate; (K) the second redirection element and the retarder element are configured in an optical path between the second light generating device and the polarization maintaining diffuser; the light generating system is configured such that second device light received by the second redirection element (and to be directed to the diffuser arrangement) comprises the first linear polarization; (L) the second redirection element is configured to direct second device light comprising the first linear polarization, received by the second redirection element, in an optical path to the diffuser arrangement; (M) the diffuser arrangement is configured to convert second device light comprising the first linear polarization, received by the diffuser arrangement, into diffused second device light comprising the second linear polarization; (N) the second redirection element is configured to direct (a) luminescent material light having a wavelength in the first luminescence wavelength range (XLR1) (received via the first redirection element), (b) luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) and comprising the first linear polarization (received via the first redirection element), and (c) diffused second device light comprising the second linear polarization, received by the second redirection element, into an optical path to the light exit; and (O) the light generating system is configured to generate system light comprising (in an operational mode of the light generating system,) one or more of (a) at least part of the luminescent material light having a wavelength in the first luminescence wavelength range (XLR1), (b) at least part of the luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) and comprising the first linear polarization, and (c) at least part of the diffused second device light comprising the second linear polarization.

[0028] With such a system it may be possible to combine beams of spectrally different types of light while minimizing loss of spectral intensity in overlapping spectral ranges. For instance, this would provide a relatively efficient solution for combining a broadband emitter have a centroid wavelength in the green-yellow wavelength range, but also having spectral power in the orange-red wavelength range, with a source of light also having spectral power in the orange-red wavelength range. Further, this may provide a relatively safe solution for high-power sources to be combined with (high-intensity) light of a source of 2024PF80214

[0029] 11 luminescent material light. Further, with the present invention it may in embodiments be possible to control color point, CRI, and / or CCT of the light generated with the system.

[0030] As indicated above, the invention provides in embodiments a light generating system comprising a first light generating device, a second light generating device, a luminescent material element, optics, and a light exit. Here below, embodiments of the light generating system will be further elucidated.

[0031] The light generating devices may be configured to generate device light. In embodiments, the light generating devices may comprise (at least) a first light generating device and a second light generating device.

[0032] The first light generating device may, in embodiments, be configured to generate first device light. Therefore, in embodiments, the first light generating device may comprise a first light source. The first light source may be essentially any light source, see also further below. Especially, in embodiments, the (first light source of the) first light generating device may comprise a first solid state light source. Hence, in embodiments, the first light generating device may comprise one or more of a laser diode, a superluminescent diode, and a multi -junction diode (e.g. a stacked multi -junction light-emitting diode (LED)). The first light generating device may herein also comprise a plurality of first (solid state) light sources. Especially, in specific embodiments, the first light generating device may comprise a first laser bank comprising a plurality of first lasers. A laser bank may comprise a relatively dense assembly of multiple laser diodes on a shared substrate provided with collimating optics, such as collimating lenses comprising one lens per laser diode. The use of laser banks may especially be convenient for projecting a beam of high power laser light onto a luminescent converter without the need for using an inverse beam expander.

[0033] Further, in embodiments, the first light generating device may especially be configured to generate first device light having a first peak wavelength (Xpi). Especially, in embodiments, the first device light may have a first peak wavelength (Xpi) selected from the wavelength range of 300-490 nm, more especially selected from the wavelength range of 380-490 nm, such as especially selected from the wavelength range of 430-490 nm, such as from the range of 440-480 nm, like from the range of 445-475 nm. Hence, in embodiments, the first device light may be blue light.

[0034] Analogously to the first light generating device, in embodiments, the second light generating device may be configured to generate second device light. Therefore, in embodiments, the second light generating device may comprise a second light source. The second light source may be essentially any light source, see also further below. Especially, in 2024PF80214

[0035] 12 embodiments, the (second light source of the) second light generating device may comprise a second solid state light source. Hence, in embodiments, the second light generating device may comprise one or more of a laser diode, a superluminescent diode, and a (stacked) multijunction (light-emitting) diode (LED). In embodiments, the second light generating device may comprise essentially the same light generating device as the first light generating device. However, in other embodiments, the first light generating device and the second light generating device may be substantially different. The second light generating device may herein also comprise a plurality of second (solid state) light sources. Especially, in specific embodiments, the second light generating device may comprise a second laser bank comprising a plurality of second lasers.

[0036] Further, in embodiments, the second light generating device may especially be configured to generate second device light having a second peak wavelength (Xp2). Especially, in embodiments, the second device light may have a second peak wavelength (Xp2) selected from the wavelength range of 300-780 nm, more especially selected from the wavelength range of 380-780 nm. The (second) peak wavelengths may be selected amongst others in dependence of the luminescent material, see also below.

[0037] Hence, in embodiments the light generating devices may comprise (i) a first light generating device configured to generate first device light, and (ii) a second light generating device configured to generate second device light; wherein the first light generating device and the second light generating device comprise one or more of a laser diode, a superluminescent diode, and a (stacked) multi -junction (light-emitting) diode.

[0038] Therefore, in embodiments the first light generating device may be configured to generate first device light, wherein the first device light may have a first peak wavelength (kpl) selected from the wavelength range of 380-490 nm, and wherein the first light generating device may comprise a (first) solid-state light source selected from the group of diode lasers, superluminescent diodes, and multi -junction diodes. The first device light may essentially consist of light of the (first) solid-state light source selected from the group of diode lasers, superluminescent diodes, and multi -junction diodes (comprised by the first light generating device). In embodiments, the first light generating device consists of one or more of (a) one or more diode lasers, (b) one or more superluminescent diodes, and (c) one or more multi -junction diodes.

[0039] In embodiments, the first light generating device (and the second light generating device) may be configured to provide first device light (and second device light, respectively) to the optics. 2024PF80214

[0040] 13

[0041] The first device light may at least partly be received by the luminescent material element. Hence, the luminescent material element may be configured downstream of the first light generating device. Or, in other words, the luminescent material element may be configured in a light receiving relationship with the first light generating device. The first device light may be received by the luminescent material element via the optics.

[0042] The term “optics” may especially refer to (one or more) optical elements. Hence, the terms “optics” and “optical elements” may refer to the same items. The optics may include one or more of (specular or surface textured) reflectors (such as mirrors), collimators, lenses, prisms, diffusers, phase plates, polarizers, diffractive elements, gratings, dichroics, selectively reflective and / or selectively transmissive optics, arrays of one or more of the afore-mentioned, etc. Alternatively or additionally, the term “optics” may refer to a holographic element or a mixing rod. In embodiments, the optics may include one or more of beam expander optics and zoom lens optics. See further above for examples of optics. In embodiments, the optics may comprise an integrator, like a “Koehler integrator” (or “Kohler integrator”). In specific embodiments, the optics may comprise one or more of a homogenizing optics, collimating optics, condensing optics, and reflecting optics. For example, in embodiments, the luminescent material light and the diffused second device light may be provided (e.g. by a dichroic beam splitter or a dichroic beam combiner) along the same optical path to the light exit, and the optics may comprise a beam homogenizer configured upstream of the light exit and configured to combine and homogenize the received light and to provide (homogenized (white)) system light to the light exit.

[0043] Hence, the phrase “the first device light may be received by the luminescent material element via the optics”, and similar phrases, may indicated that the first device light may propagate via at least one optical element to the luminescent material element. When there are more optical elements, which is herein the case, the first device light may propagate via at least one optical element of the plurality of optical elements to the luminescent material element.

[0044] The terms “upstream” and “downstream” relate to an arrangement of items or features relative to the propagation of the light from a light generating means (here especially the light generating device), wherein relative to a first position within a beam of light from the light generating means, a second position in the beam of light closer to the light generating means is “upstream”, and a third position within the beam of light further away from the light generating means is “downstream”. 2024PF80214

[0045] 14

[0046] As indicated above, the light generating system may comprise a luminescent material element. The luminescent material element may especially comprise a layer of luminescent material. This layer may be partly transmissive for the first device light, when the luminescent material layer e.g. comprises a first device light transmissive crystal or a first device light transmissive ceramic body. In such embodiments, a reflector may be configured downstream of the luminescent material layer. The reflector may be a surface of a thermally conductive body or may a reflective layer on a thermally conductive body (see further also below). The thermally conductive body may be configured in thermal contact with the luminescent material layer. The luminescent material layer may in other embodiments be specularly reflective for first device light, allowing essentially no first device light be transmitted by luminescent material layer. Also in such embodiments, a thermally conductive body may be configured in thermal contact with the luminescent material layer. The thermally conductive body (and the optional reflector) may be comprised by the luminescent material element. In embodiments, the reflector may be a metallic reflector.

[0047] The luminescent material may be configured to convert at least part of first radiation (selected from one or more of UV radiation and visible radiati on)(here “first device light”), into luminescent material light. Especially, in embodiments the luminescent material may be configured to convert at least part of blue light (as radiation) into luminescent material light. Especially when blue light is partly converted, the blue light may be used as source of blue light (for the system light) and as excitation light that can be converted by the luminescent material. The first radiation may especially be provided by a (solid state) light source. Hence, in embodiments, the luminescent material may be configured to convert at least part of first device light received by the luminescent material (element) into luminescent material light. Especially, in embodiments, the luminescent material may be configured to convert at least 50%, such as at least 60%, like at least 70%, especially at least 80%, more especially at least 90%, including 100% of the first device light received by the luminescent material (element) into luminescent material light. Additionally or alternatively, in embodiments, the luminescent material may be configured to convert at least part of second device light received by the luminescent material into luminescent material light. Especially, in embodiments, the luminescent material may be configured to convert at least 50%, such as at least 60%, like at least 70%, especially at least 80%, more especially at least 90%, including 100% of the second device light received by the luminescent material (element) into luminescent material light. 2024PF80214

[0048] 15

[0049] When different luminescent materials are applied, one or more luminescent materials may be configured to convert incident light into one or more of green and yellow luminescent material light, and one or more other luminescent materials may be configured to convert incident light into one or more of orange and red luminescent material light.

[0050] The term “luminescent material” especially refers to a material that can convert first radiati on, (especially one or more of UV radiation and blue radiation,) into second radiation. In general, the first radiation and second radiation have different spectral power distributions. Hence, instead of the term “luminescent material”, also the terms “luminescent converter” or “converter” may be applied. Further, instead of the term “luminescent material” also the term “phosphor” may be applied. These terms are known to the person skilled in the art. In general, the second radiation has a spectral power distribution at larger wavelengths than the first radiation, which is the case in the so-called downconversion. In specific embodiments, however the second radiation has a spectral power distribution with intensity at smaller wavelengths than the first radiation, which is the case in the so-called up-conversion.

[0051] In embodiments, the “luminescent material” may especially refer to a material that can convert radiation into e.g. visible and / or infrared light. For instance, in embodiments the luminescent material may be able to convert one or more of UV radiation and blue radiation, into visible light. The luminescent material may in specific embodiments also convert radiation into infrared radiation (IR). Hence, upon excitation with radiation, the luminescent material emits radiation. In general, the luminescent material will be a down converter, i.e. radiation of a smaller wavelength is converted into radiation with a larger wavelength (Xex<Xem), though in specific embodiments the luminescent material may comprise up-converter luminescent material, i.e. radiation of a larger wavelength is converted into radiation with a smaller wavelength ( x> m).

[0052] In embodiments, the term “luminescence” may refer to phosphorescence. In embodiments, the term “luminescence” may also refer to fluorescence. Instead of the term “luminescence”, also the term “emission” may be applied. Hence, the terms “first radiation” and “second radiation” may refer to excitation radiation and emission (radiation), respectively. Likewise, the term “luminescent material” may in embodiments refer to phosphorescence and / or fluorescence.

[0053] The term “luminescent material” may also refer to a plurality of different luminescent materials. Hence, the term “luminescent material” may in specific embodiments also refer to a luminescent material composition. The term “luminescent material” herein 2024PF80214

[0054] 16 may also refer to a material comprising a luminescent material, such as a light transmissive host comprising the luminescent material. Examples of possible luminescent materials are indicated further below.

[0055] In embodiments, luminescent materials are selected from garnets and nitrides, especially doped with trivalent cerium or divalent europium, respectively. The term “nitride” may also refer to oxynitride or nitridosilicate, etc. Alternatively or additionally, the luminescent material(s) may be selected from silicates, especially doped with divalent europium.

[0056] Especially, the luminescent material is configured to convert at least part of the light source light into luminescent material light, wherein the luminescent material may comprise a (garnet) luminescent material of the type AsBsOn Ce, wherein A comprises one or more of Y, La, Gd, Tb and Lu, and wherein B comprises one or more of Al, Ga, In and Sc. Hence, the luminescent material light may e.g. be green light or yellow light (or in specific embodiments even orange (dependent upon the composition of the garnet and cerium concentration)). However, other embodiments are also possible, see below. In embodiments, 0.05-10% of the A elements comprise Ce, even more especially 0.05-5%, such as 0.1-5%. Especially, embodiments, 0.1-3% of the A elements comprise Ce, such as up to 2%, like selected from the range of 0.1-1.5%, such as at least above 0.5%.

[0057] Especially, a luminescent material comprises conversion material or is a conversion material. A luminescent material converts light from a light source, such as the light source light, into secondary light (here the luminescent material light). The luminescent material may comprise an organic group that converts the light, or a molecule that converts the light, or an inorganic group that converts the light, etc. Such groups (or molecule) may be indicated as converter element. The garnet type material as indicated above, comprises cerium (Ce) as converter element. Cerium comprising garnets are well known in the art.

[0058] Hence, in specific embodiments the luminescent material comprises a (first) luminescent material of the type AsBsOn Ce, wherein A in embodiments comprises one or more of Y, La, Gd, Tb and Lu, especially (at least) one or more of Y, Gd, Tb and Lu, and wherein B in embodiments comprises one or more of Al, Ga, In and Sc. Especially, A may comprise one or more of Y, Gd and Lu, such as especially one or more of Y and Lu. Especially, B may comprise one or more of Al and Ga, more especially at least Al, such as essentially entirely Al. Hence, especially suitable luminescent materials are cerium comprising garnet materials. Embodiments of garnets especially include A3B5O12 garnets, wherein A comprises at least yttrium or lutetium and wherein B comprises at least aluminum. 2024PF80214

[0059] 17

[0060] Such garnets may be doped with cerium (Ce), with praseodymium (Pr) or a combination of cerium and praseodymium; especially however with Ce. Especially, B comprises aluminum (Al), however, B may also partly comprise gallium (Ga) and / or scandium (Sc) and / or indium (In), especially up to about 20% of Al, more especially up to about 10 % of Al (i.e. the B ions essentially consist of 90 or more mole % of Al and 10 or less mole % of one or more of Ga, Sc, and In); B may especially comprise up to about 10% gallium. In another variant, B and O may at least partly be replaced by Si and N. The element A may especially be selected from the group consisting of yttrium (Y), gadolinium (Gd), terbium (Tb) and lutetium (Lu). Further, Gd and / or Tb are especially only present up to an amount of about 20% of A. In a specific embodiment, the garnet luminescent material comprises (Yi-xLux)3B50i2:Ce, wherein x is equal to or larger than 0 and equal to or smaller than 1. The term “:Ce”, indicates that part of the metal ions (i.e. in the garnets: part of the “A” ions) in the luminescent material is replaced by Ce. For instance, in the case of (Yi-xLux)3A150i2:Ce, part of Y and / or Lu is replaced by Ce. This is known to the person skilled in the art. Ce will replace A in general for not more than 10%; in general, the Ce concentration will be in the range of 0.1 to 4%, especially 0.1 to 2% (relative to A). Assuming 1% Ce and 10% Y, the full correct formula could be (Yo.iLuo.89Ceo.oi)3A150i2. Ce in garnets is substantially or only in the trivalent state, as is known to the person skilled in the art.

[0061] In embodiments, the luminescent material (thus) comprises A3B5O12 wherein in specific embodiments at maximum 10% of B-0 may be replaced by Si-N.

[0062] In specific embodiments the luminescent material comprises (YXI-X2-X3A’X2CeX3)3(Alyi-y2B’y2)5Oi2, wherein xl+x2+x3=l, wherein x3>0, wherein 0<x2+x3<0.2, wherein yl+y2=l, wherein 0<y2<0.2, wherein A’ comprises one or more elements selected from the group consisting of lanthanides, and wherein B’ comprises one or more elements selected from the group consisting of Ga, In and Sc. In embodiments, x3 is selected from the range of 0.001-0.1. In the present invention, especially xl>0, such as >0.2, like at least 0.8. Garnets with Y may provide suitable spectral power distributions.

[0063] In specific embodiments at maximum 10% of B-0 may be replaced by Si-N. Here, B in B-0 refers to one or more of Al, Ga, In and Sc (and O refers to oxygen); in specific embodiments B-0 may refer to Al-O. As indicated above, in specific embodiments x3 may be selected from the range of 0.001-0.04. Especially, such luminescent materials may have a suitable spectral distribution (see however below), have a relatively high efficiency, have a relatively high thermal stability, and allow a high CRI (optionally in combination with (the) light of other sources of light as described herein). Hence, in specific embodiments A 2024PF80214

[0064] 18 may be selected from the group consisting of Lu and Gd. Alternatively or additionally, B may comprise Ga. Hence, in embodiments the luminescent material comprises (YXI-X2- x3( u,Gd)x2Cex3)3(Alyi-y2Gay2)5Oi2, wherein Lu and / or Gd may be available. Even more especially, x3 is selected from the range of 0.001-0.1, wherein 0<x2+x3<0.1, and wherein 0<y2<0.1. Further, in specific embodiments, at maximum 1% of B-0 may be replaced by Si- N. Here, the percentage refers to moles (as known in the art); see e.g. also EP3149108. In yet further specific embodiments, the luminescent material comprises (Yxi-xsCexs^ALOn, wherein xl+x3=l, and wherein 0<x3<0.2, such as 0.001-0.1.

[0065] In specific embodiments, the light generating device may only include luminescent materials selected from the type of cerium comprising garnets. In even further specific embodiments, the light generating device includes a single type of luminescent materials, such as (Yxi-x2-x3A’x2Cex3)3(Alyi-y2B’y2)5Oi2. Hence, in specific embodiments the light generating device comprises luminescent material, wherein at least 85 weight%, even more especially at least about 90 wt.%, such as yet even more especially at least about 95 weight % of the luminescent material comprises (Yxi-x2-x3A’x2Cex3)3(Alyi-y2B’y2)5Oi2. Here, wherein A’ comprises one or more elements selected from the group consisting of lanthanides, and wherein B’ comprises one or more elements selected from the group consisting of Ga, In and Sc, wherein xl+x2+x3=l, wherein x3>0, wherein 0<x2+x3<0.2, wherein yl+y2=l, wherein 0<y2<0.2. Especially, x3 is selected from the range of 0.001-0.1. Note that in embodiments x2=0. Alternatively or additionally, in embodiments y2=0.

[0066] In specific embodiments, A may especially comprise at least Y, and B may especially comprise at least Al.

[0067] Alternatively or additionally, the luminescent material may comprise a luminescent material of the type AsSieNiuCe3, wherein A comprises one or more of Y, La, Gd, Tb and Lu, such as in embodiments one or more of La and Y.

[0068] In specific embodiments, the luminescent material may comprise at least two different luminescent materials configured to provide luminescent material light having different spectral power distributions. As can be derived from the above, the term “different luminescent materials” may refer to luminescent materials that are different, or to two compositions, each including at least one luminescent material in common, but wherein the compositions differ. For instance, a primary luminescent material comprising luminescent materials A and B, and a secondary luminescent material comprising only A or only B, or comprising both A and B, but in a different weight ratio. Such primary luminescent material 2024PF80214

[0069] 19 and secondary luminescent material may have different spectral power distributions of their respective luminescent material light.

[0070] The garnet type luminescent material may also be described with an alternative formula AsB^C’^On. Here, A may comprise one or more of (i) rare earth ions, such as one or more selected from Y3+, Lu3+, Gd3+, Tb3+, La3+, and (ii) divalent cations, such as Ca2+. Here, B may comprise one or more of (i) trivalent cations, such as one or more of Al3+, Ga3+, Sc3+, Sb3+, and In3+, and (ii) divalent cations, such as one or more of Mg2+and Mn2+. Here, C may comprise one or more of (i) trivalent cations, such as one or more of Ga3+and Al3+, (ii) divalent cations, such as Mn2+, and (iii) tetravalent cations, such as one or more of Si4+and Ge4+. With such ions, the garnet crystal structure can be maintained. Other substitutions than mentioned may also be possible.

[0071] In embodiments, the luminescent material may alternatively or additionally comprise one or more of MS:Eu2+and / or ESisNs Eu2and / or MAlSiNs Eu2and / or Ca2AlSi3O2Ns:Eu2+, etc., wherein M comprises one or more of Ba, Sr and Ca, especially in embodiments at least Sr. Hence, in embodiments, the luminescent material may comprise one or more materials selected from the group consisting of (Ba,Sr,Ca)S:Eu, (Ba,Sr,Ca)AlSiN3:Eu and (Ba,Sr,Ca)2SisN8:Eu. In these compounds, europium (Eu) is substantially or only divalent, and replaces one or more of the indicated divalent cations. In general, Eu will not be present in amounts larger than 10% of the cation; its presence will especially be in the range of about 0.5 to 10%, more especially in the range of about 0.5 to 5% relative to the cation(s) it replaces. The term “:Eu”, indicates that part of the metal ions is replaced by Eu (in these examples by Eu2+). For instance, assuming 2% Eu in CaAlSi Eu, the correct formula could be (Cao.98Euo.o2)AlSiN3. Divalent europium will in general replace divalent cations, such as the above divalent alkaline earth cations, especially Ca, Sr or Ba. The material (Ba,Sr,Ca)S:Eu can also be indicated as MS:Eu, wherein M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca); especially, M comprises in this compound calcium or strontium, or calcium and strontium, more especially calcium. Here, Eu is introduced and replaces at least part of M (i.e. one or more of Ba, Sr, and Ca). Further, the material (Ba,Sr,Ca)2SisN8:Eu can also be indicated as NESis Eu, wherein M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca); especially, M comprises in this compound Sr and / or Ba. In a further specific embodiment, M consists of Sr and / or Ba (not taking into account the presence of Eu), especially 50 to 100%, more especially 50 to 90% Ba and 50 to 0%, especially 50 to 10% Sr, such as Bai.sSro.sSis Eu (i.e. 75 % Ba; 25% Sr). Here, Eu is 2024PF80214

[0072] 20 introduced and replaces at least part of M, i.e. one or more of Ba, Sr, and Ca). Likewise, the material (Ba,Sr,Ca)AlSiN3:Eu can also be indicated as MAlSi Eu, wherein M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca); especially, M comprises in this compound calcium or strontium, or calcium and strontium, more especially calcium. Here, Eu is introduced and replaces at least part of M (i.e. one or more of Ba, Sr, and Ca). Eu in the above indicated luminescent materials is substantially or only in the divalent state, as is known to the person skilled in the art. Hence, such nitride luminescent materials may also be or comprise converter elements, here especially Eu2+.

[0073] Especially, the luminescent material may be an inorganic luminescent material, such as one or more of the above-described trivalent cerium or divalent europium comprising oxides, oxynitrides, or nitrides.

[0074] In embodiments, a red luminescent material may comprise one or more materials selected from the group consisting of (Ba,Sr,Ca)S:Eu, (Ba,Sr,Ca)AlSiN3:Eu and (Ba,Sr,Ca)2SisN8:Eu. In these compounds, europium (Eu) is substantially or only divalent, and replaces one or more of the indicated divalent cations. In general, Eu will not be present in amounts larger than 10% of the cation; its presence will especially be in the range of about 0.5 to 10%, more especially in the range of about 0.5 to 5% relative to the cation(s) it replaces. The term “:Eu”, indicates that part of the metal ions is replaced by Eu (in these examples by Eu2+). For instance, assuming 2% Eu in CaAlSi Eu, the correct formula could be (Cao.98Euo.o2)AlSiN3. Divalent europium will in general replace divalent cations, such as the above divalent alkaline earth cations, especially Ca, Sr or Ba.

[0075] The material (Ba,Sr,Ca)S:Eu can also be indicated as MS:Eu, wherein M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca); especially, M comprises in this compound calcium or strontium, or calcium and strontium, more especially calcium. Here, Eu is introduced and replaces at least part of M (i.e. one or more of Ba, Sr, and Ca).

[0076] Further, the material (Ba,Sr,Ca)2SisN8:Eu can also be indicated as NfcSis Eu, wherein M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca); especially, M comprises in this compound Sr and / or Ba. In a further specific embodiment, M consists of Sr and / or Ba (not taking into account the presence of Eu), especially 50 to 100%, more especially 50 to 90% Ba and 50 to 0%, especially 50 to 10% Sr, such as Bai.sSro.sSis Eu (i.e. 75 % Ba; 25% Sr). Here, Eu is introduced and replaces at least part of M, i.e. one or more of Ba, Sr, and Ca). 2024PF80214

[0077] 21

[0078] Likewise, the material (Ba,Sr,Ca)AlSiN3:Eu can also be indicated as MAI Si N3: Eu, wherein M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca); especially, M comprises in this compound calcium or strontium, or calcium and strontium, more especially calcium. Here, Eu is introduced and replaces at least part of M (i.e. one or more of Ba, Sr, and Ca).

[0079] Eu in the above indicated luminescent materials is substantially or only in the divalent state, as is known to the person skilled in the art.

[0080] In specific embodiments, the luminescent material may comprise one or more of (a) a luminescent material of the type AiBsO^ Ce, wherein A comprises one or more of Y, La, Gd, Tb and Lu, and wherein B comprises one or more of Al, Ga, In and Sc, and (b) a luminescent material selected from the types of a divalent europium comprising nitride luminescent material and a divalent europium comprising oxynitride luminescent material.

[0081] Blue luminescent materials may comprise YSO (Y2SiOs:Ce3+), or similar compounds, or BAM (BaMgAlioOi?:Eu2+), or similar compounds.

[0082] The term “luminescent material” herein especially relates to inorganic luminescent materials. Alternatively or additionally, also other luminescent materials may be applied. For instance quantum dots and / or organic dyes may be applied and may optionally be embedded in transmissive matrices like e.g. polymers, like PMMA, or polysiloxanes, etc. etc. Quantum dots are small crystals of semiconducting material generally having a width or diameter of only a few nanometers. When excited by incident light, a quantum dot emits light of a color determined by the size and material of the crystal. Light of a particular color can therefore be produced by adapting the size of the dots. Most known quantum dots with emission in the visible range are based on cadmium selenide (CdSe) with a shell such as cadmium sulfide (CdS) and zinc sulfide (ZnS). Cadmium free quantum dots such as indium phosphide (InP), and copper indium sulfide (CuInS?) and / or silver indium sulfide (AglnS?) can also be used. Quantum dots show very narrow emission band and thus they show saturated colors. Furthermore the emission color can easily be tuned by adapting the size of the quantum dots. Any type of quantum dot known in the art may be used in the present invention. However, it may be preferred for reasons of environmental safety and concern to use cadmium-free quantum dots or at least quantum dots having a very low cadmium content. Instead of quantum dots or in addition to quantum dots, also other quantum confinement structures may be used. The term “quantum confinement structures” should, in the context of the present application, be understood as e.g. quantum wells, quantum dots, quantum rods, tripods, tetrapods, or nano-wires, etcetera. Organic phosphors can be used as well. Examples 2024PF80214

[0083] 22 of suitable organic phosphor materials are organic luminescent materials based on perylene derivatives, for example compounds sold under the name Lumogen® by BASF. Examples of suitable compounds include, but are not limited to, Lumogen® Red F305, Lumogen® Orange F240, Lumogen® Yellow F083, and Lumogen® F170.

[0084] Different luminescent materials may have different spectral power distributions of the respective luminescent material light. Alternatively or additionally, such different luminescent materials may especially have different color points (or dominant wavelengths).

[0085] As indicated above, other luminescent materials may also be possible. Hence, in specific embodiments the luminescent material is selected from the group of divalent europium containing nitrides, divalent europium containing oxynitrides, divalent europium containing silicates, cerium comprising garnets, and quantum structures. Quantum structures may e.g. comprise quantum dots or quantum rods (or other quantum type particles) (see above). Quantum structures may also comprise quantum wells. Quantum structures may also comprise photonic crystals.

[0086] The luminescent material may be comprised by a luminescent body. The luminescent body may be a layer, like a self-supporting layer. The luminescent body may also be a coating. The luminescent body may also comprise a luminescent coating on a support (especially a light transmissive support in the transmissive mode). Especially, the luminescent body may essentially be self-supporting. In embodiments, the luminescent material may be provided as luminescent body, such as a luminescent single crystal, a luminescent glass, or a luminescent ceramic body. Such body may be indicated as “converter body” or “luminescent body”. In embodiments, the luminescent body may be a luminescent single crystal or a luminescent ceramic body. For instance, in embodiments a cerium comprising garnet luminescent material may be provided as a luminescent single crystal or as a luminescent ceramic body. In other embodiments, the luminescent body may comprise a light transmissive body, wherein the luminescent material is embedded. For instance, the luminescent body may comprise a glass body, with luminescent material embedded therein. Or, the glass as such may be luminescent. In other embodiments, the luminescent body may comprise a polymeric body, with luminescent material embedded therein.

[0087] In specific embodiments, the luminescent body comprises a ceramic body comprising the luminescent material. Ceramic bodies are known in the art. Alternatively, the luminescent body comprises single crystal. In yet further specific embodiments, different types of luminescent bodies may be applied. Hence, the body may especially be selected 2024PF80214

[0088] 23 from single crystalline bodies and ceramic bodies. The latter may be more easily made than the former, while they nevertheless may have good optical and / or thermal properties. Hence, in embodiments the body may be a ceramic body. However, in specific embodiments also a combination of single crystalline bodies and ceramic bodies may be applied. Especially, the luminescent body comprises a ceramic luminescent body. Hence, in specific embodiments the luminescent body is defined by a ceramic luminescent material. Therefore, in specific embodiments the luminescent material is a luminescent material that can be provided a ceramic luminescent body. Hence, the luminescent body may comprise a ceramic luminescent body.

[0089] Hence, in embodiments, the luminescent material element may especially comprise a luminescent body comprising a luminescent material. Further, in embodiments, the (luminescent body comprising the) luminescent material may be configured in thermal contact with a thermally conductive material. Especially, in embodiments where the luminescent material is configured in the reflective mode, such thermal contact may be beneficial as the luminescent material may give rise to significant thermal dissipation. Similarly, in some embodiments, the diffuser may be configured in thermal contact with a thermally conductive material. An element may be considered in “thermal contact” with another element if it can exchange energy through the process of heat. Hence, the elements may be thermally coupled. In embodiments, thermal contact can be achieved by physical contact. In embodiments, thermal contact may be achieved via a thermally conductive material, such as a thermally conductive glue (or thermally conductive adhesive). Thermal contact may also be achieved between two elements when the two elements are arranged relative to each other at a distance of equal to or less than about 10 pm, though larger distances, such as up to 100 pm may be possible. The shorter the distance, the better the thermal contact. Especially, the distance is 10 pm or less, such as 5 pm or less, such as 1 pm or less. The distance may be the distanced between two respective surfaces of the respective elements. The distance may be an average distance. For instance, the two elements may be in physical contact at one or more, such as a plurality of positions, but at one or more, especially a plurality of other positions, the elements are not in physical contact. For instance, this may be the case when one or both elements have a rough surface. When two elements are in thermal contact, they may be in physical contact or may be configured at a short distance of each other, like at maximum 10 pm, such as at maximum 1 mm. When the two elements are configured at a distance from each other, an intermediate material may be configured in between, though in other embodiments, the distance between the two elements may filled 2024PF80214

[0090] 24 with a gas, liquid, or may be vacuum. When an intermediate material is available, the larger the distance, the higher the thermal conductivity may be useful for thermal contact between the two elements. However, the smaller the distance, the lower the thermal conductivity of the intermediate material may be (of course, higher thermal conductive materials may also be used).

[0091] A thermally conductive material may especially have a thermal conductivity of at least about 20 W / (m*K), like at least about 30 W / (m*K), such as at least about 100 W / (m*K), like especially at least about 200 W / (m*K). In yet further specific embodiments, a thermally conductive material may especially have a thermal conductivity of at least about 10 W / (m*K). In embodiments, the thermally conductive material may comprise one or more of copper, aluminum, silver, gold, silicon carbide, aluminum nitride, boron nitride, aluminum silicon carbide, beryllium oxide, a silicon carbide composite, aluminum silicon carbide, a copper tungsten alloy, a copper molybdenum carbide, carbon, diamond, and graphite. Alternatively, or additionally, the thermally conductive material may comprise or consist of aluminum oxide. In embodiments, the thermally conductive material may be comprised by and / or configured in thermal contact with one or more of a heatsink, a heat spreader, and a two-phase cooling device.

[0092] In embodiments, the light generating system may comprise a rotatable element, wherein the rotatable element comprises the luminescent material. During operation of the light generating system (in an operational mode of the light generating system) the rotatable element may rotate, such that over time different parts of the luminescent material are irradiated by the device light. This may assist in heat management of the luminescent material. In embodiments, the rotatable element may e.g. comprise one of a phosphor wheel, a rotating phosphor disc, and a rotating rod comprising the luminescent material as a cylindrical track.

[0093] As indicated above, the luminescent material element may comprise a luminescent material. Further, as indicated above, the luminescent material may especially be configured to convert at least part of the first device light received by the luminescent material element into luminescent material light.

[0094] The wavelength range between 380-780 nm is generally considered as the relevant spectral wavelength range for visible light. Luminescent material light somewhere in this wavelength range may be divided into two (or more) parts. A first part may be in a first (luminescence) wavelength range selected from the 380-780 nm range and a second part may be in a second (luminescence) wavelength range selected from the 380-780 nm range. 2024PF80214

[0095] 25

[0096] Just for the sake of argument, assuming an emission band having spectral intensity (spectral power) at all wavelengths between 510-630 nm, then optionally the first luminescence wavelength range and the second luminescence wavelength range may e.g. respectively be 500-600 nm and 600-680 nm, or 510-590 nm and 590-630 nm, or 500-610 nm and 610-640 nm. Alternatively, assuming an emission band having spectral intensity (spectral power) at all wavelengths between 510-630 nm, then optionally the second luminescence wavelength range and the first luminescence wavelength range may e.g. respectively be 500-600 nm and 600-680 nm, or 510-590 nm and 590-630 nm, or 500-610 nm and 610-640 nm. Note that these are only examples, and alternative choices may also be possible. Further, a division in more than two parts may also be possible, though such solution will still provide a first (luminescence) wavelength range and a second (luminescence) wavelength range (and thus at least a further (luminescence) wavelength range. When there is a single integral emission band, then in general the (luminescence) wavelength ranges may be adjacent, like in the examples above. Would there be more than one emission band, then the at least two (luminescence) wavelength ranges may be adjacent, but are not necessarily adjacent. Further, note that the first luminescence wavelength range may not necessarily be at smaller wavelengths than the second luminescence wavelength range. Further note that the first luminescence wavelength range and the second luminescence wavelength range may not overlap, or only share an end point.

[0097] Hence, in embodiments in at least part of a first luminescence wavelength range (ZLR1) and in at least part of a second luminescence wavelength range (ZLR2) the luminescent material light may have (non-zero) spectral power. As can be derived from the above, at one or more wavelengths in the first luminescence wavelength range (ZLR1) and at one or more wavelengths in the second luminescence wavelength range (ZLR2) the luminescent material light has intensity (spectral power). However, as can be derived above, the terminology of the first luminescence wavelength range (ZLR1) and the second luminescence wavelength range (ZLR2) does not necessarily imply that at all wavelengths in the first luminescence wavelength range (ZLR1) and / or at all wavelengths in the second luminescence wavelength range (ZLR2) the luminescent material light has intensity (spectral power) (see examples above where at all wavelengths in the first luminescence wavelength range (ZLR1) and / or at all wavelengths in the second luminescence wavelength range (ZLR2) the luminescent material light has intensity (spectral power) and examples wherein not at all wavelengths in the first luminescence wavelength range (ZLR1) and / or at all wavelengths in the second luminescence wavelength range (ZLR2) the luminescent material light has 2024PF80214

[0098] 26 intensity (spectral power). Hence, the luminescent material light may comprise a first part and a second part of luminescent material light.

[0099] In general, however, it may be useful to select a luminescence wavelength range, be it the first luminescence wavelength range (XLR1) or the second luminescence wavelength range (XLR2), such that between the end wavelengths of the range at least 95%, more especially at least 98%, such as at least 99%, like 100% of the spectral power of the luminescent material light is available. Further, it may be useful when the luminescence wavelength range (be it the first luminescence wavelength range (ZLR1) or the second luminescence wavelength range (XLR2)), does not extend more than about 5 nm beyond the wavelengths of the spectral power distribution of the (respective) luminescence wavelength range, where its intensity is equal to or lower than 0.1% of the maximum intensity of the spectrally closest emission band within the respective luminescence wavelength range. Hence, assuming above-mentioned luminescence wavelength range (be it the first luminescence wavelength range (ZLR1) or the second luminescence wavelength range (kLR.2)) having spectral intensity (spectral power) at all wavelengths between 510-660 nm with at 510.1 nm and 659.9 nm spectral intensities equal to 0.1% of the maximum intensity of the spectrally closest emission band, then in embodiments the second luminescence wavelength range (ZLR2) may be defined as 505.1-654.9 nm, though other ranges may also be possible (see also above). Note that the first luminescence wavelength range (ZLR1) together with the second luminescence wavelength range (ZLR2) may in embodiments also be smaller than the full luminescence emission band. In general, this may not necessarily be the case when there is only a first luminescence wavelength range (ZLR1) and the second luminescence wavelength, but this may be the case when more than two luminescence wavelength ranges are applied, e.g. in embodiments wherein yet another type of device light (different from the second device light, may e.g. be admixed with the luminescent material light). Especially, however, in embodiments the two (or more) luminescence wavelength ranges may be selected such, that they are the narrowest wavelength ranges that (together) include the wavelengths of the luminescent material light providing at least 99%, more especially at least 99.9% of the spectral power (especially 100% of the spectral power).

[0100] The first luminescence wavelength range (ZLR1) and the second luminescence wavelength range (ZLR2) will further also be explained in relation to the second device light wavelength range.

[0101] The light generating system may be configured to generate system light. The system light may comprise luminescent material light. However, it may be desirable to add 2024PF80214

[0102] 27 one or more other types of light and / or to replace the luminescent material light with one or more other types of light. For instance, it may be desirable (a) to provide two different colors, or (b) to provide essentially the same colors, but with different color rendering indices (CRI), or (c) to provide two (or more) different types of white light having a difference in relation to one or more of correlated color temperature (CCT), color rendering index (CRI), and color point, (d) to allow compensation for changes over time of the luminescent material light, etc. To this end, second device light may be provided by the light generating system, which second device light may end up in the system light, e.g. alongside the luminescent material light or alternative to the luminescent material light.

[0103] Hence, in embodiments the second light generating device may be configured to generate second device light, wherein in at least part of a second device light wavelength range (XDR2) the second device light has spectral power, and wherein the second light generating device may comprise a (second) solid-state light source selected from the group of diode lasers, superluminescent diodes, and multi -junction diodes. The second device light may essentially consist of light of the (second) solid-state light source selected from the group of diode lasers, superluminescent diodes, and multi -junction diodes (comprised by the second light generating device). In embodiments, the second light generating device consists of one or more of (a) one or more diode lasers, (b) one or more superluminescent diodes, and (c) one or more multi -junction diodes.

[0104] In embodiments, the second light generating device (and the first light generating device) may be configured to provide second device light (and first device light, respectively), to the optics.

[0105] Several embodiments may be possible as second device light may be brought in an optical path via the optics to the light exit (especially via the second redirection element) without having the second device light diffused, or having the second device light diffused via the diffuser arrangement, or having the second device light diffused via another diffuser (e.g. a transmissive diffuser). Especially, the second redirection element may comprise a polarizing beam combiner. However, the second redirection element may also comprise an arrangement of two or more polarizing beam combiners.

[0106] When the second device light is not diffused before reaching the second redirection element, or when the second device light is diffused via a transmissive diffuser, then the light generating system may be configured such that the second device light reaching the second redirection element may have the second polarization. In this way, (a) the luminescent material light having a wavelength in the second luminescence wavelength range 2024PF80214

[0107] 28 and comprising the first polarization and (b) second device light comprising the second polarization may be directed, via a (polarization based) second direction element, in an optical path to the light exit.

[0108] However, when the second device light is diffused via the herein described diffuser arrangement (in the reflective mode), then the light generating system may be configured such that the diffused second device light reaching the second redirection element may comprise the second polarization. In this way, (a) the luminescent material light having a wavelength in the second luminescence wavelength range and comprising the first polarization and (b) second device light comprising the second polarization may be directed, via a (polarization based) second direction element, in an optical path to the light exit.

[0109] Hence, the second device light may at least partly be received by a diffuser arrangement (via the optics) (see also below). Hence, the diffuser arrangement may be configured downstream of the second light generating device. Or, in other words, the diffuser arrangement may be configured in a light receiving relationship with the second light generating device. The second device light may be received by the diffuser arrangement (in the reflective mode) via the optics.

[0110] The (reflective mode) diffuser arrangement may be an option.

[0111] Hence, the phrase “the second device light may be received by the diffuser arrangement via the optics”, and similar phrases, may indicate that the second device light may propagate via at least one optical element to the diffuser arrangement. When there are more optical elements, which is herein the case, the second device light may propagate via at least one optical element of the plurality of optical elements to the diffuser arrangement.

[0112] Especially, the second device light wavelength range (XDR2) may be selected such that essentially all spectral power of the second device light in the visible wavelength range is within the second device light wavelength range (XDR2). Just for the sake of argument, assuming a second device light emission band having spectral intensity (spectral power) at all wavelengths between 560-670 nm, then options for the second device light wavelength range may e.g. be 560-670 nm, or 510-700 nm, or 560-690 nm. Note that these are only examples, and alternative choices may also be possible.

[0113] In general, however, it may be useful to select the second device light wavelength range (ZDR2) such that between the end wavelengths of the range at least 95%, more especially at least 98%, such as at least 99%, like 100% of the spectral power of the second device light is available (similarly, this may apply to the device light wavelength range of device light of other types of light generating devices). Further, it may be useful 2024PF80214

[0114] 29 when the second device light wavelength range (ADR.2) does not extend more than about 5 nm beyond the wavelengths of the spectral power distribution of the second device light, where its intensity is equal to or lower than 0.1% of the maximum intensity of the spectrally closest emission band within the second device light wavelength range (XDR2). Hence, assuming above-mentioned second device light emission band having spectral intensity (spectral power) at all wavelengths between 560-670 nm with at 560.1 nm and 669.9 nm spectral intensities equal to 0.1% of the maximum intensity of the spectrally closest emission band, then in embodiments the second device light wavelength range (XDR2) may be defined as 555.1-704.9 nm, though other ranges may also be possible (see also above). Especially, however, the one (or more) second device light wavelength range(s) may be selected such, that it is (they are) the narrowest wavelength range(s) that (together) includes the wavelengths of the second device light providing at least 99%, more especially at least 99.9% of the spectral power (especially 100% of the spectral power).

[0115] The second device light may essentially have any spectral power distribution which may be desirable to combine with the luminescent material light or to replace the luminescent material light (see also above). However, its spectral power distribution as well as the spectral power distribution of the luminescent material light may be such, that using a dichroic beam combiner may lead to loss of part of the spectral power of the luminescent material light or part of the spectral power of the second device light. Hence, in general this may imply that the spectral power distribution of the luminescent material light and the spectral power distribution of the second device either at least partially overlap, or are spectrally neighboring, for instance within about 10 nm, or even within about 5 nm. Hence, in embodiments the second luminescence wavelength range (XLR2) and the second device light wavelength range (XDR2) may at least partially overlap, more especially may overlap over a range of at least 10 nm, such as at least 20 nm, like at least 30 nm. For instance, the second luminescence wavelength range (ZLR2) and the second device light wavelength range (ZDR2) may overlap for up to about 100 nm, like up to about 80 nm. Optionally, in embodiments the first luminescence wavelength range (ZLR1) and the second device light wavelength range (ZDR2) may also at least partially overlap.

[0116] In specific embodiments the second luminescence wavelength range (ZLR2) and the second device light wavelength range (ZDR2) may be same wavelength range. In yet specific other embodiments, the second device light wavelength range (ZDR2) is more narrow than the second luminescence wavelength range (ZLR2) and all wavelengths of the 2024PF80214

[0117] 30 second device light wavelength range (XDR2) are also comprised by the second luminescence wavelength range (XLR2).

[0118] Especially, in embodiments the second device light may have a second peak wavelength (Ap2) within the second luminescence wavelength range (ZLR2).

[0119] However, in yet other embodiments, the first luminescence wavelength range (kLR I ) and the second device light wavelength range (ZDR2) do not spectrally overlap. However, for instance, in such embodiments the second luminescence wavelength range (ZLR2) and the second device light wavelength range (ZDR2) may have an inter wavelength range distance of at maximum 20 nm, such as at maximum 10 nm.

[0120] It may be desirable that the spectral power (of the luminescent material light) in the second luminescence wavelength range (ZLR2) is lower than the spectral power (of the luminescent material light) in the first luminescence wavelength range (ZLR1). In specific embodiments, in the first luminescence wavelength range (ALR I ) the luminescent material light may have a first spectral power Pl, and in the second luminescence wavelength range (kLR.2) the luminescent material light may have a second spectral power P2, wherein especially 0.01<P2 / Pl<l, such as in embodiments 0.05<P2 / Pl<0.5.

[0121] To combine the luminescent material light and the second device light, herein a hybrid solution is proposed, wherein the luminescent material light in the first luminescence wavelength range (ZLR I ) may be combined with the second device light independent of the polarization of the luminescent material light in the first luminescence wavelength range (ZLR1), whereas the luminescent material light in the second luminescence wavelength range (ZLR2) may be combined with the second device light on the basis of their polarization, i.e. via polarization multiplexing. Hence, here below the optics, amongst others used for aforementioned combinations of types of light, are described.

[0122] As indicated above, the optics may comprise redirection elements, and a diffuser arrangement. Amongst others, the redirection elements may comprise a first redirection element, a second redirection element, and a third redirection element.

[0123] In specific embodiments, the first redirection element and the third redirection element may be configured in an optical path between the first light generating device and the luminescent material element. Hence, first device light from the first light generating device received by the luminescent material element may propagate from the first light generating device via the first redirection element and the third redirection element to the luminescent material element. 2024PF80214

[0124] 31

[0125] The phrase “... light received by ...”, and similar phrases, such as “device light received by the first redirection element” may especially indicate that when the light is actually received by an item, an action may take place. The action may in embodiments be one or more of conversion, reflection, and transmission. Further, the action may also include refraction. Whether or not such item receives light may e.g. depend on e.g. a controlling mode (for instance whether or not a light generating device provides light).

[0126] In embodiments, the first redirection element may be configured to direct (such as transmit) at least part of the first device light received by the first redirection element to the luminescent material element via the third redirection element. The first redirection element may in embodiments direct by transmitting or reflecting the first device light received by the first redirection element to the luminescent material element. The first redirection element may in embodiments direct luminescent material light by transmitting or reflecting the luminescent material light received by the first redirection element in an optical path in the direction of the light exit (via the second redirection element).

[0127] Hence, in embodiments the first redirection element may be configured to transmit first device light (received from the first light generating device) (to the luminescent material element (via the third redirection element)) and reflect luminescent material light (received from the luminescent material element (via the third redirection element) (in an optical path to the second redirection element). In other embodiments, the first redirection element may be configured to reflect first device light (received from the first light generating device) (to the luminescent material element (via the third redirection element)) and transmit luminescent material light (received from the luminescent material (via the third redirection element)) (in an optical path to the second redirection element).

[0128] Assuming first device light propagating from the first light generating device to the luminescent material element, in embodiments the first redirection element may be configured downstream of the first light generating device and upstream of the third redirection element, the third redirection element may (thus) be configured downstream of the first redirection element and upstream of the luminescent material element, and the luminescent material element may (thus) be configured downstream of the third redirection element.

[0129] In embodiments, the third redirection element may be transmissive for first device light, received by the third redirection element. In this way, first device light may reach the luminescent material element. Further, in embodiments, the third redirection element may be transmissive for luminescent material light having a wavelength in the first 2024PF80214

[0130] 32 luminescence wavelength range (XLR1), received by the third redirection element. In this way, the luminescent material light, generated by the luminescent material by converting at least part of the first device light, having a wavelength in the first luminescence wavelength range (XLR1), may be directed, irrespective of its polarization, via the optics, to a light exit. Hence, the luminescent material light having a wavelength in the first luminescence wavelength range (XLR1) may comprise s-polarized light and / or p-polarized light. Or, in specific embodiments the luminescent material light having a wavelength in the first luminescence wavelength range (XLR1) may comprise first linear polarized light and second linear polarized light, different from the first linear polarized light, e.g. orthogonal to first linear polarized light.

[0131] Yet further, in embodiments, the third redirection element may be transmissive for luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) comprising a first linear polarization, received by the third redirection element. In this way, luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) comprising a first linear polarization, received by the third redirection element may be directed, via the optics, to the light exit. The first linear polarization may be s-polarization or p-polarization. Furthermore, in embodiments, the third redirection element may be reflective for luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) and comprising a second linear polarization, different from the first linear polarization, received by the third redirection element. This light may be lost, unless (a kind of) recycling is applied, see also below. Hence, the third redirection element may be a reflective polarizer or polarizing beam splitter for (luminescent material) light having a wavelength in the second luminescence wavelength range (ZLR2). However, the reflection and / or transmission properties of the third redirection element may be independent of the polarization of the (luminescent material) light in the first luminescence wavelength range (ZLR I ). Further, the reflection and / or transmission properties of the third redirection element may also be independent of the polarization of the first device light.

[0132] Therefore, in embodiments the third redirection element may be (a) transmissive for first device light, received by the third redirection element, (b) transmissive for luminescent material light having a wavelength in the first luminescence wavelength range (ZLR1), received by the third redirection element, (c) transmissive for luminescent material light having a wavelength in the second luminescence wavelength range (ZLR2) comprising a first linear polarization, received by the third redirection element, and (d) 2024PF80214

[0133] 33 reflective for luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) and comprising a second linear polarization, different from the first linear polarization, received by the third redirection element.

[0134] As indicated above, the luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) and comprising a second linear polarization might be lost, as it may not be directed to the light exit at the third (polarization based) redirection element. However, this light may be redirected to the luminescent material element where due to scattering at the luminescent material and / or by reabsorption, the redirected luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) and comprising the second linear polarization may at least partly be converted into luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) and comprising the first linear polarization. The scattering may e.g. be based on surface scattering and / or volume scattering. Therefore, in embodiments the optics (thus comprising the third polarization based redirection element) may be configured such that at least part of the luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) and comprising the second linear polarization may be directed back to the luminescent material element. In this way, the third (polarization based) redirection element may serve as gate, allowing luminescent material light having a wavelength in the first luminescence wavelength range (ZLR1), and luminescent material light having a wavelength in the second luminescence wavelength range (ZLR2) and comprising the first linear polarization, received by the first redirection element, to propagate in a direction to the light exit, and returning luminescent material light having a wavelength in the second luminescence wavelength range (ZLR2) and comprising the second linear polarization (to the luminescent material element), such that it may be recycled into luminescent material light having a wavelength in the second luminescence wavelength range (ZLR2) and comprising the first linear polarization. This may occur for multiple cycles, by which a substantial part of the luminescent material light having a wavelength in the second luminescence wavelength range (ZLR2) and comprising the second linear polarization may be converted into luminescent material light having a wavelength in the second luminescence wavelength range (ZLR2) and comprising the first linear polarization. Hence, the light generating system may be configured such that at least part of the luminescent material light having a wavelength in the second luminescence wavelength range (ZLR2) and comprising the second linear polarization that is received by the luminescent material element after having been directed back thereto, may be converted into further luminescent material light 2024PF80214

[0135] 34 having a wavelength in a second luminescence wavelength range (XLR2) and comprising the first linear polarization.

[0136] The term “further luminescent material light” may refer to the luminescent material light that emanates away from the luminescent material after the luminescent material has received reflected luminescent material light back. Note that in the system light, when luminescent material light is comprised, this may thus consist of luminescent material light and further luminescent material light, which may be shortly indicated as “luminescent material light”, as, being originally generated, or after reflection, it is light that originates from the luminescent material due to conversion of the first device light. When the luminescent material is reflected back on the luminescent material, one or more of two processes may occur: (a) the luminescent material light may be reflected (again, but now at the luminescent material), and (b) the luminescent material light may be partly be reabsorbed, and emitted as luminescent material light. In general, at least the former process may occur. However, the latter process may in embodiments also occur. In the former process, the spectral power distribution of the luminescent material light propagating to the luminescent material and being reflected at the luminescent material, and the spectral power distribution of the luminescent material light emanating from the luminescent material (due to the reflection at the luminescent material), may essentially be the same. In the latter process, however, the spectral power distribution of the luminescent material light propagating to the luminescent material and at least partly being reabsorbed by the luminescent material, and the spectral power distribution of the luminescent material light emanating from the luminescent material (due to conversion by the luminescent material), may differ, as a reabsorption process may lead to a redshift. Hence, the luminescent material light escaping from the light generating system may comprise (a) a contribution of the luminescent material light having a wavelength in the first wavelength range, and (b) one or more of (bl) a contribution of the luminescent material light having a wavelength in the second wavelength range due to essentially scattering (reflection) at the luminescent material, (b2) a contribution of the luminescent material light having a wavelength in the second wavelength range due to reconversion by the luminescent material. The spectral power distributions of the luminescent material light under (bl) and (b2) may thus differ.

[0137] Therefore, relative to a configuration wherein no recycling is applied, the intensity of the luminescent material light that escapes from the system may be higher. Should, due to recycling, there be some reabsorption, then the luminescent material light that 2024PF80214

[0138] 35 escapes from the system may also be red-shifted (relative to a configuration wherein no recycling is applied).

[0139] Therefore, in this way a redirection element may be used to separate first device light and a first part of the luminescent material light, such that first device light may reach the luminescent material, and thus a first part of the thus generated luminescent material light may be directed in an optical path to the light exit. Hence, in embodiments the first redirection element may comprises a multichroic based beam splitter, such as a dichroic based beam splitter, especially for the first device light and the first luminescence wavelength range (only).

[0140] However, the same first redirection element may be used to direct the second part of the luminescent material light on the basis of its polarization, such that luminescent material light comprised by the second part having a predefined linear polarization may propagate in an optical path to the light exit, whereas luminescent material light comprised by the second part having another predefined linear polarization may be recycled by directing it in an optical path (back) to the luminescent material element. In this respect, the first redirection element may have a polarizing beam splitter function. Hence, as indicated above, in embodiments the first redirection element may be configured to direct (a) luminescent material light having a wavelength in the first luminescence wavelength range (ZLR1), and (b) luminescent material light having a wavelength in the second luminescence wavelength range (ZLR2) and comprising the first linear polarization, received by the first redirection element, in an optical path to the light exit, via a second redirection element.

[0141] As indicated above, it may be desirable to include second device light in the system light, alternative to the luminescent material light or in addition to the luminescent material light. To this end, the second redirection element may be applied. Especially, the second redirection element may be applied to bring the light directed by the first redirection element to the second redirection element and the second device light in a (single) optical path in the direction of the light exit.

[0142] Especially, however, it may be desirable to provide diffuse second device light. Hence, herein embodiments are described wherein the second redirection element may be applied to bring the light directed by the first redirection element to the second redirection element and diffused second device light in a (single) optical path in the direction of the light exit. Here below, embodiments to accomplish this are described. 2024PF80214

[0143] 36

[0144] In embodiments, the diffuser arrangement may comprise a retarder element and a diffuser, especially a polarization maintaining diffuser. Especially, in embodiments the retarder element may comprises a X / 4 plate.

[0145] In embodiments, the diffuser may especially comprise a substantially polarization maintaining diffuser, i.e., the diffuser may be configured to substantially maintain the polarization of the incident light upon diffusion (and in some embodiments reflection). Therefore, in embodiments, the diffuser may comprise a metal coated surface textured glass substrate mounted on a heat conductive material such as e.g. a metal or a ceramic. In such embodiments, the heat conductive material may be configured to conduct away heat that may be generated in the diffuser due to some absorption of incident device light.

[0146] A polarization maintaining diffuser may especially be desirable when the diffuser arrangement may be configured as colinear arrangement. In such embodiments, device light, which may substantially not be diffused, propagating to the diffuser arrangement may propagate for at least part of its optical path via a same optical path as diffused device light (i.e. device light having been diffused at the diffuser and propagating away from the diffuser.

[0147] To separate these two types of light that may have essentially the same spectral power distributions, but may only differ in extent of diffusion (i.e. beam angle), a retarder may be applied in combination with a (second) polarization based redirection element.

[0148] Hence, in embodiments, the diffuser arrangement may comprise a X / 4 waveplate. As known from the art, a waveplate or retarder is an optical device that alters the polarization state of a light wave travelling through it. A halfwave plate may shift the polarization direction of linearly polarized light (especially from s to p or from p to s polarization), and a quarter-wave plate may convert linearly polarized light into elliptically (such as especially circularly) polarized light (and vice versa). The X / 4 waveplate may especially be configured between (relative to the propagation of light through the system) the (second) polarization based redirection element and the diffuser. In embodiments, the second polarization based redirection element may thus be configured to direct (first device light and / or second) device light received by the second polarization based redirection element and comprising (either) the first linear polarization or the second linear polarization (optionally via optics) to the X / 4 waveplate. The X / 4 waveplate may, in embodiments, be configured to convert (first device light and / or second) device light received by the X / 4 waveplate 2024PF80214

[0149] 37 comprising a linear polarization into (first device light and / or second) device light having a (first) circular polarization. At the diffuser, in embodiments, the (first device light and / or second) device light having the (first) circular polarization may be diffused into diffused device light having a second circular polarization. Therefore, in embodiments, the X / 4 waveplate may also be configured to convert diffused device light received by the X 4 waveplate (via the diffuser) and having the (second) circular polarization into diffused device light comprising a linear polarization. For example, in embodiments, p-polarized (first device light and / or second) device light may be directed by the second polarization based redirection element to the X / 4 waveplate. In such embodiments, the X / 4 waveplate may be configured to convert the p-polarized (first device light and / or second) device light into left-handed circularly polarized (first device light and / or second) device light. Further, in such embodiments, the diffuser may be configured to diffuse the left-handed circularly polarized (first device light and / or second) device light received by the diffuser into right-handed circularly polarized diffused device light. The X / 4 waveplate may then, in embodiments, be configured to convert the right-handed circularly polarized diffused device light received by the X / 4 waveplate (back) to linearly polarized light, especially to s-polarized diffused device light. However, in embodiments, different polarizations and conversions from the example described here may be possible too, such as e.g. starting from s-polarized (first device light and / or second) device light.

[0150] Hence, in embodiments, the luminescent material element and the diffuser arrangement may both be configured in the reflective mode; wherein the diffuser arrangement may comprise a polarization maintaining diffuser, and wherein the diffuser arrangement may further comprise a X / 4 waveplate configured between the second (polarization based) redirection element and the diffuser, wherein the second (polarization based) redirection element may be configured to direct second device light received by the second (polarization based) redirection element and comprising the first linear polarization or the second linear polarization (optionally via optics) to the X / 4 waveplate, wherein the X / 4 waveplate may be configured to (i) convert second device light received by the X / 4 waveplate and comprising a linear polarization into second device light having a (first) circular polarization, and (ii) convert diffused device light received by the X / 4 waveplate (via the diffuser) and comprising a (second) circular polarization into diffused device light comprising a linear polarization.

[0151] Further, in embodiments wherein a colinear (reflective) diffuser arrangement is applied, the optics may thus (further) comprise a second (polarization based) redirection 2024PF80214

[0152] 38 element. The second (polarization based) redirection element may be configured to direct device light comprising a first linear polarization in an optical path to the diffuser arrangement, and direct (returning) diffused device comprising a second linear polarization (complementary to the first linear polarization) in an optical path to the light exit. For the sake of completeness, this may thus also mean that the second (polarization based) redirection element may be configured to direct device light comprising a second linear polarization in an optical path to the diffuser arrangement, and direct (returning) diffused device comprising a first linear polarization (complementary to the second linear polarization) in an optical path to the light exit.

[0153] Hence, in embodiments the diffuser arrangement may be configured as colinear arrangement, wherein incoming second device light, received by the diffuser arrangement, may propagate over at least part of its optical path colinear with an optical path of the diffused device light propagating from the diffuser arrangement to the light exit. Further, in (such) embodiments the diffuser arrangement may thus comprise a polarization maintaining diffuser. Especially, in (such) embodiments the diffuser arrangement may further comprise a X / 4 waveplate configured between the second (polarization based) redirection element and the diffuser, wherein the second polarization based redirection element may be configured to direct second device light, received by the second (polarization based) based redirection element, and first device light (and optionally device light of other light generating devices, see below ), received by the second (polarization based) redirection element, to the / 4 waveplate, wherein the X / 4 waveplate may be configured to convert linear polarized light received by the X / 4 waveplate into elliptical polarized light and to convert elliptical polarized light received by the X / 4 waveplate into linear polarized light.

[0154] In the colinear (reflective) configuration of the diffuser arrangement, incoming light, comprising second device light and optional first device light, on the diffuser, may have an optical axis (Oi) having a first angle (ai) with a normal to the diffuser essentially equal to 0°, and the outgoing diffused device light may have an optical axis (Oo), having a second angle (ao) relative to the normal to the diffuser essentially equal to 0° (or 180°), wherein the optical axes (Oi,Oo) may have a mutual angle (P) of essentially equal to 0° (or 180°). When taking the direction of propagation into account, the second angle (ao) relative to the normal to the diffuser may be considered essentially equal to 180° and the mutual angle (P) may also be considered essentially equal to 180°, as the directions may be anti -parallel.

[0155] Hence, the diffuser arrangement may be configured to convert second device light comprising the first linear polarization, received by the diffuser arrangement, into 2024PF80214

[0156] 39 diffused second device light comprising the second linear polarization. Therefore, in embodiments the second redirection element and the retarder element may be configured in an optical path between the second light generating device and the polarization maintaining diffuser. Further, in embodiments the light generating system may be configured such that second device light received by the second redirection element may comprise the first linear polarization. Though in the term “first linear polarization” “first” may only be an indication, especially, however, the first linear polarization in relation to the third redirection element and the first linear polarization in relation to the second device light, as well as the first linear polarization in relation to the second redirection element, may be the same linear polarization, such as either p-polarization or s-polarization. Likewise, this applies to “second linear polarization”, wherein the second linear polarization in relation to the third redirection element and the second linear polarization in relation to the second redirection element may be the same linear polarization, such as either s-polarization or p-polarization.

[0157] Especially, in embodiments the second redirection element may be configured to direct second device light comprising the first linear polarization, received by the second redirection element, in an optical path to the diffuser arrangement. Hence, the second redirection element may be a polarizing beam splitter in (or for) light having a wavelength in the second device light wavelength range (ZDR2). Therefore, in embodiments the second redirection element may comprise a polarizing beam splitter for the second device light. However, the second redirection element may essentially be transmissive (or in other embodiments essentially reflective) for (luminescent material) light having a wavelength in the first luminescence wavelength range (ZLR1).

[0158] A polarizing beam splitter may be considered an example of (polarization based) redirection optics or (polarization based) redirection optics. Light propagating to the polarizing beam splitter, and comprising both linear polarizations, like elliptically polarized light, may be split in two orthogonally propagating beams of light with complementary linear polarizations. Hence, this provides the polarizing beam splitter its beam splitting function. However, the opposite may also be true, two beams of light with complementary linear polarizations orthogonally propagating to the polarizing beam splitter may be combined in a single beam comprising both complementary linear polarizations and propagating along an axis parallel to an axis of one of the two beams of light with complementary linear polarizations orthogonally propagating to the polarizing beam splitter. Hence, a polarizing beam splitter may also be indicated as a polarizing beam combiner. With a polarizing beam 2024PF80214

[0159] 40 combiner two beams of light having different linear polarizations may be multiplexed (i.e. combined).

[0160] Hence, for the polarizing beam splitter may apply that for a first polarization, the transmission may be higher, like at least 10% points higher, such as at least 20% points higher, or even at least 30 % points higher, than for a second polarization. Similarly, for a first polarization, the reflection may be lower, like at least 10% points lower, such as at least 20% points lower, or even at least 30 % points lower, than for a second polarization. Especially, in embodiments, (assuming light comprising both linear polarizations, like elliptically polarized light,) the polarizing beam splitter may be configured to direct at least 60%, like at least 80%, more especially at least 90%, such as at least about 95%, of the light of the first polarization to a first direction and at least 60%, like at least 80%, more especially at least 90%, such as at least about 95%, of the light of the second polarization to a second direction, wherein the directions may in embodiments have a mutual angle selected from the range 45-135°, such as about 90°. The percentage of the light may refer to a spectral power (e.g. in Watt). Especially, the first polarization and the second polarization may comprise linear polarizations such as selected from s polarization and p polarization. Optionally, the first polarization and the second polarization may be selected from different elliptically polarized light. In embodiments, the polarizing beam splitters herein may be selected from reflective polarizing beam splitters (reflective polarizers).

[0161] The term “linear polarized light” (or “linearly polarized light”) may herein refer to light having (electric field) oscillations predominantly aligned in a single plane. Hence, it is not excluded that some oscillations occur outside of the single plane, such as in a plane perpendicular thereto. For instance, in embodiments, the linear polarized light may have at least 80% of (electric field) oscillations in a single plane, such as at least 90%, especially at least 95%, such as at least 99%, including 100%. The linearly polarized light may, in embodiments, also comprise elliptically polarized light with a large ratio of perpendicular polarization components, such as a ratio > 4, especially > 6, such as > 10, especially > 20. As known in the art, linear polarized light may be generated by optical elements of solid state lasers, e.g., polarizing filters, laser cavity dimensional and / or structural characteristics, and / or intracavity elements. The linear polarizations s-polarized and p-polarized may be considered complementary polarizations (or orthogonal polarizations).

[0162] The phrase “to direct light”, and similar phrases, in relation to (redirection) optical elements, may (a) refer to redirecting light, whereby there may be a non-zero angle (e.g. an angle of 80-100°, such as an angle of 90°) between the optical axis of the light 2024PF80214

[0163] 41 propagating to the (redirection) optical element and the optical axis of the light emanating from the (redirection) optical element, but may (b) also refer to allowing light to pass (i.e., transmitting light), whereby there may be an angle of < 10°, such as a zero angle (i.e. parallel) between the optical axis of the light propagating to the (redirection) optical element and the optical axis of the light emanating from the (redirection) optical element. For instance, a (redirection) optical element may direct light, received by the (redirection) optical element to another optical element, whereby the redirection optical element receives light along two orthogonal (optical) paths, wherein the light from both paths may be of different types (e.g. of different polarizations, spectral power distributions, etc.), wherein one of the types of light (from one of the (optical) paths) is reflected by the (redirection) optical element to the other optical element (i.e. non-zero angle), and another one of the types of light (from the other (optical) path) is transmitted by the (redirection) optical element to the other optical element (i.e. zero angle) (and thus both are directed to that optical element). Therefore, a (redirection) optical element such as a reflector, a dichroic mirror, a polarizing beam splitter, and a lens, etc., may direct light received by such (redirection) optical element.

[0164] Hence, in embodiments the second redirection element may be configured to direct (a) luminescent material light having a wavelength in the first luminescence wavelength range (XLR1) (received via the first redirection element), (b) luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) and comprising the first linear polarization (received via the first redirection element), and (c) diffused second device light comprising the second linear polarization, received by the second redirection element, into an optical path to the light exit. Further, in embodiments the second redirection element may be configured to direct (undiffused) second device light comprising the first linear polarization, received by the second redirection element, to the diffuser arrangement. Especially, in embodiments the second redirection element may be configured to (a) transmit luminescent material light having a wavelength in the first luminescence wavelength range (XLR1) (received via the first redirection element), (b) transmit luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) and comprising the first linear polarization (received via the first redirection element), and (c) reflect diffused second device light comprising the second linear polarization, received by the second redirection element, into an optical path to the light exit. Further, in embodiments the second redirection element may be configured to transmit (undiffused) second device light comprising the first linear polarization, received by the second redirection element, to the diffuser arrangement. 2024PF80214

[0165] 42

[0166] Hence, the light exit may receive via the second redirection element one or more of (a) at least part of the luminescent material light having a wavelength in the first luminescence wavelength range (XLR1), (b) at least part of the luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) and comprising the first linear polarization, and (c) at least part of the diffused second device light comprising the second linear polarization.

[0167] The term “second redirection element” may also refer to a plurality of redirection elements, such as two redirection elements. In this way, a single redirection element that is used to direct second device light to the diffuser arrangement as well as direct diffused second device light and luminescent material light in an optical path to the light may be replaced by a primary second redirection element and a secondary second redirection element.

[0168] Hence, in embodiments the system may comprise a plurality of second redirection elements, wherein a primary second redirection element and the retarder element may be configured in an optical path between the second light generating device and the polarization maintaining diffuser. Further, the light generating system may be configured such that second device light received by the primary second redirection element comprises the first linear polarization. Yet, in embodiments the primary second redirection element may be configured to direct second device light comprising the first linear polarization, received by the second redirection element, in an optical path to the diffuser arrangement. Further, in embodiments the diffuser arrangement may be configured to convert second device light comprising the first linear polarization, received by the diffuser arrangement, into diffused second device light comprising the second linear polarization. Moreover, in embodiments the primary second redirection element may be configured to direct diffused second device light comprising the second linear polarization, received by the primary second redirection element, in an optical path to the secondary second redirection element. Further, in embodiments the secondary second redirection element may be configured to direct (a) luminescent material light having a wavelength in the first luminescence wavelength range (XLR1) (received via the first redirection element), (b) luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) and comprising the first linear polarization (received via the first redirection element), and (c) diffused second device light comprising the second linear polarization, received by the second redirection element via the primary second redirection element, into an optical path to the light exit. Hence, in embodiments the light generating system may be configured to generate system light 2024PF80214

[0169] 43 comprising, (in an operational mode of the light generating system,) one or more of (a) at least part of the luminescent material light having a wavelength in the first luminescence wavelength range (XLR1), (b) at least part of the luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) and comprising the first linear polarization, and (c) at least part of the diffused second device light comprising the second linear polarization.

[0170] In embodiments, the system may comprise a light exit, like an end window or an (other) optical element, like a lens, or an opening, from which the system light may escape to the external of the system. Hence, the term “light exit” may refer to a part of the system, such as in specific embodiment a part in a housing enclosing the herein described elements of the light generating system (such as optics and light generating devices), from which the system light may emanate (during an operational mode of the light generating system. Hence, the system may comprise a housing, comprising such light exit. The housing may at least partly enclose one or more light generating devices and one or more (other) optical elements.

[0171] Yet, in embodiments the light generating system may be configured to generate system light comprising, (in an operational mode of the light generating system) one or more of (a) at least part of the luminescent material light having a wavelength in the first luminescence wavelength range (ZLR1), (b) at least part of the luminescent material light having a wavelength in the second luminescence wavelength range (ZLR2) and comprising the first linear polarization, and (c) at least part of the diffused second device light comprising the second linear polarization.

[0172] The system, or apparatus, or device may execute an action in a “mode” or “operation mode” or “mode of operation” or “operational mode”. The term “operational mode may also be indicated as “controlling mode”. Likewise, in a method an action or stage, or step may be executed in a “mode” or “operation mode” or “mode of operation” or “operational mode”. This does not exclude that the system, or apparatus, or device may also be adapted for providing another controlling mode, or a plurality of other controlling modes. Likewise, this may not exclude that before executing the mode and / or after executing the mode one or more other modes may be executed.

[0173] Would there be a single operational mode, then in embodiments the system light may comprise (a) at least part of the luminescent material light having a wavelength in the first luminescence wavelength range (ZLR1), (b) at least part of the luminescent material light having a wavelength in the second luminescence wavelength range (ZLR2) and 2024PF80214

[0174] 44 comprising the first linear polarization, and (c) at least part of the diffused second device light comprising the second linear polarization.

[0175] When a control system is comprised by the system, there may be more operational modes. Hence, in such embodiments the system light may comprise one or more of (a) at least part of the luminescent material light having a wavelength in the first luminescence wavelength range (XLR1), (b) at least part of the luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) and comprising the first linear polarization, and (c) at least part of the diffused second device light comprising the second linear polarization.

[0176] The term “controlling” and similar terms especially refer at least to determining the behavior or supervising the running of an element. Hence, herein “controlling” and similar terms may e.g. refer to imposing behavior to the element (determining the behavior or supervising the running of an element), etc., such as e.g. measuring, displaying, actuating, opening, shifting, changing temperature, etc. Beyond that, the term “controlling” and similar terms may additionally include monitoring. Hence, the term “controlling” and similar terms may include imposing behavior on an element and also imposing behavior on an element and monitoring the element. The controlling of the element can be done with a control system, which may also be indicated as “controller”. The control system and the element may thus at least temporarily, or permanently, functionally be coupled. The element may comprise the control system. In embodiments, the control system and element may not be physically coupled. Control can be done via wired and / or wireless control. The term “control system” may also refer to a plurality of different control systems, which especially are functionally coupled, and of which e.g. one control system may be a master control system and one or more others may be slave control systems. A control system may comprise or may be functionally coupled to a user interface.

[0177] The control system may also be configured to receive and execute instructions from a remote control. In embodiments, the control system may be controlled via an App on a device, such as a portable device, like a Smartphone or I-phone, a tablet, etc. The device is thus not necessarily coupled to the lighting system, but may be (temporarily) functionally coupled to the lighting system.

[0178] Hence, in embodiments the control system may (also) be configured to be controlled by an App on a remote device. In such embodiments the control system of the lighting system may be a slave control system or control in a slave mode. For instance, the lighting system may be identifiable with a code, especially a unique code for the respective 2024PF80214

[0179] 45 lighting system. The control system of the lighting system may be configured to be controlled by an external control system which has access to the lighting system on the basis of knowledge (input by a user interface of with an optical sensor (e.g. QR code reader) of the (unique) code. The lighting system may also comprise means for communicating with other systems or devices, such as on the basis of Bluetooth, Thread, WIFI, LiFi, ZigBee, BLE or WiMAX, or another wireless technology.

[0180] However, in embodiments a control system may be available, that is adapted to provide at least the controlling mode. Would other modes be available, the choice of such modes may especially be executed via a user interface, though other options, like executing a mode in dependence of a sensor signal or a (time) scheme, may also be possible. The operation mode may in embodiments also refer to a system, or apparatus, or device, which can only operate in a single operation mode (i.e. “on”, without further tunability).

[0181] Hence, in embodiments, the control system may control in dependence of one or more of an input signal of a user interface, a sensor signal (of a sensor), and a timer. The term “timer” may refer to a clock and / or a predetermined time scheme.

[0182] Therefore, in embodiments the light generating may further comprise a control system, wherein the control system may be configured to control a spectral power distribution of the system light by individually controlling the first light generating device and the second light generating device (and the optional third light generating device, see below).

[0183] In embodiments, one or more of the light generating devices, such as in specific embodiments all, may be operated in a pulsed mode. The first light generating device and the second light generating device may also be operated in the pulsed mode, such that they do not provide device light at the same time. Especially, however, in embodiments the pulse frequencies may be chosen such, that would they be operated in the pulsed mode both at the same time (and with constant power), the human eye will essentially see a constant spectral power distribution of the system light. Hence, in embodiments the light generating system may be configured such that the first light generating device and the second light generating device are operated in the first operational mode of the light generating system in a pulsed mode with pulse frequencies of 50 Hz or larger.

[0184] In embodiments, the luminescent material light may have spectral power in at least one of (a) a 490-560 nm wavelength range and (b) a 560-640 nm wavelength range. For instance, YsAhOn Ce3may have a broad band emission with spectral power in both wavelength ranges. Hence, in embodiments the second luminescence wavelength range 2024PF80214

[0185] 46

[0186] (XLR2) and the second device light wavelength range (XDR2) are at least partly comprised in a wavelength range of 490-640 nm. Especially, in embodiments the second device light has a second peak wavelength (Zp2) in the green-yellow wavelength range. Further, in specific embodiments, the second device light may have a second peak wavelength (Zp2) in the yellow-red wavelength range.

[0187] The terms “violet light” or “violet emission”, and similar terms, may especially relate to light having a wavelength in the range of about 380-440 nm. In specific embodiments, the violet light may have a centroid wavelength in the 380-440 nm range. The terms “blue light” or “blue emission”, and similar terms, may especially relate to light having a wavelength in the range of about 440-490 nm (including some violet and cyan hues). In specific embodiments, the blue light may have a centroid wavelength in the 440-490 nm range. The terms “green light” or “green emission”, and similar terms, may especially relate to light having a wavelength in the range of about 490-560 nm. In specific embodiments, the green light may have a centroid wavelength in the 490-560 nm range. The terms “yellow light” or “yellow emission”, and similar terms, may especially relate to light having a wavelength in the range of about 560-590 nm. In specific embodiments, the yellow light may have a centroid wavelength in the 560-590 nm range. The terms “orange light” or “orange emission”, and similar terms, may especially relate to light having a wavelength in the range of about 590-620 nm. In specific embodiments, the orange light may have a centroid wavelength in the 590-620 nm range. The terms “red light” or “red emission”, and similar terms, may especially relate to light having a wavelength in the range of about 620-780 nm, such as 620-750 nm. In specific embodiments, the red light may have a centroid wavelength in the 620-780 nm range, such as 620-750 nm. The terms “cyan light” or “cyan emission”, and similar terms, especially relate to light having a wavelength in the range of about 490- 520 nm. In specific embodiments, the cyan light may have a centroid wavelength in the 490- 520 nm range. The terms “amber light” or “amber emission”, and similar terms, may especially relate to light having a wavelength in the range of about 585-605 nm, such as about 590-600 nm. In specific embodiments, the amber light may have a centroid wavelength in the 585-605 nm range. The phrase “light having one or more wavelengths in a wavelength range” and similar phrases may especially indicate that the indicated light (or radiation) has a spectral power distribution with at least intensity or intensities at these one or more wavelengths in the indicate wavelength range. For instance, a blue emitting solid state light source will have a spectral power distribution with intensities at one or more wavelengths in the 440-495 nm wavelength range. 2024PF80214

[0188] 47

[0189] The phrase “in the green-yellow wavelength range”, and similar phrases, may indicate spectral power at one or more wavelengths in the green wavelength range and / or spectral power at one or more wavelengths in the yellow wavelength range. The green-yellow wavelength range is defined as the 490-590 nm wavelength range. Note that the luminescent material providing luminescent material light having spectral power in the green-yellow wavelength range may in embodiments only have spectral power in this 490-590 nm wavelength range (within the 380-780 nm wavelength range), but may in other embodiments also have spectral power within the 380-780 nm wavelength range at other wavelengths than within the 490-590 nm wavelength range.

[0190] The phrase “in the orange-red wavelength range”, and similar phrases, may indicate spectral power at one or more wavelengths in the orange wavelength range and / or spectral power at one or more wavelengths in the red wavelength range. The orange-red wavelength range is defined as the 590-780 nm wavelength range. Note that the luminescent material providing luminescent material light having spectral power in the orange-red wavelength range may in embodiments only have spectral power in this 590-780 nm wavelength range (within the 380-780 nm wavelength range), but may in other embodiments also have spectral power within the 380-780 nm wavelength range at other wavelengths than within the 590-780 nm wavelength range. The terms “orange-red light” or “orange-red emission”, and similar terms, may especially relate to light having a wavelength in the range of about 590-780 nm, more especially in the range of 590-750 nm.

[0191] The term “centroid wavelength”, also indicated as c, is known in the art, and refers to the wavelength value where half of the light energy is at shorter and half the energy is at longer wavelengths; the value is stated in nanometers (nm). It is the wavelength that divides the integral of a spectral power distribution into two equal parts as expressed by the formula Ze = X A* 1(A) / (S I( A)), where the summation is over the wavelength range of interest, and 1(A) is the spectral energy density (i.e. the integration of the product of the wavelength and the intensity over the emission band normalized to the integrated intensity). The centroid wavelength may e.g. be determined at operation conditions.

[0192] In embodiments, the first light generating device may comprise one or more semiconductor lasers. Alternatively or additionally, in embodiments the second light generating device may comprise one or more semiconductor lasers. Further, in embodiments the first light generating device may comprises a laser bank (see also above) comprising a plurality of semiconductor lasers. Yet, alternatively or additionally, the second light generating device may comprise a laser bank comprising a plurality of semiconductor lasers. 2024PF80214

[0193] 48

[0194] In embodiments, the second light generating device may be configured to generate second device light having a second peak wavelength (Zp2) in the 610-680 nm wavelength range. Note, however, that other wavelength range for the first luminescence wavelength range (ZLR1), the second luminescence wavelength range (ZLR2), and the second device wavelength range (ZDR2) may also be possible.

[0195] Referring to the first light generating device, a first device light wavelength range (ZDR1) may be selected such that essentially all spectral power of the first device light (in the visible wavelength range) is within the first device light wavelength range (ZDR I ). Just for the sake of argument, assuming a first device light emission band having spectral intensity (spectral power) at all wavelengths between 460-470 nm, then options for the first device light wavelength range may e.g. be 460-470 nm, or 410-500 nm, or 460-490 nm. Note that these are only examples, and alternative choices may also be possible.

[0196] In general, however, it may be useful to select the first device light wavelength range (ADR I ) such that between the end wavelengths of the range at least 95%, more especially at least 98%, such as at least 99%, like 100% of the spectral power of the first device light is available. Further, it may be useful when the first device light wavelength range (ADR I ) does not extend more than about 5 nm beyond the wavelengths of the spectral power distribution of the first device light, where its intensity is equal to or lower than 0.1% of the maximum intensity of the spectrally closest emission band within the first device light wavelength range (ZDR1). Hence, assuming above-mentioned first device light emission band having spectral intensity (spectral power) at all wavelengths between 460-470 nm with at 460.1 nm and 469.9 nm spectral intensities equal to 0.1% of the maximum intensity of the spectrally closest emission band, then in embodiments the first device light wavelength range (ZDR1) may be defined as 455.1-474.9 nm, though other ranges may also be possible (see also above). Especially, however, the one (or more) first device light wavelength range(s) may be selected such, that it is (they are) the narrowest wavelength range(s) that (together) includes the wavelengths of the first device light providing at least 99%, more especially at least 99.9% of the spectral power (especially 100% of the spectral power).

[0197] With respect to the third redirection element, in embodiments the third redirection element may comprise a reflective polarizer for light in the second luminescence wavelength range (ALR2). This may imply that in embodiments a substantial part, or essentially all, of the luminescent material light having a wavelength in the first luminescence wavelength range (ALR I ) may be transmitted, and a substantial part, or essentially all, of the luminescent material light having a wavelength in the second luminescence wavelength range 2024PF80214

[0198] 49

[0199] (XLR2) and having the second polarization may be reflected back to the luminescent material element. In embodiments, assuming an optical axis of the luminescent material light essentially perpendicular to the third redirection element, at least 60%, like at least 80%, more especially at least 90%, such as at least about 95%, of the luminescent material light having a wavelength in the second luminescence wavelength range (ZLR2) and having the first polarization may be transmitted, and at least 60%, like at least 80%, more especially at least 90%, such as at least about 95%, of the light of the luminescent material light having a wavelength in the second luminescence wavelength range (ZLR2) and having the second polarization may be reflected back to the luminescent material element. Hence, in embodiments a reflective polarizer may be applied for light in the second luminescence wavelength range (ZLR2), which may be configured perpendicular to a normal to the luminescent material (element)(and parallel to an optical axis of the luminescent material light emanating away from the luminescent material). Hence, recycling of light having a wavelength in the second luminescence wavelength range (ZLR2) may be between the third redirection element and luminescent material (only).

[0200] With respect to the third redirection element, in other embodiments the third redirection element may comprise a polarizing beam splitter (see also above) for light in the second luminescence wavelength range (ZLR2), wherein the optics further comprises a reflective element. In such embodiments, the light generating system may be configured such that at least part of the luminescent material light having a wavelength in the second luminescence wavelength range (ZLR2) and comprising the second linear polarization propagates in an optical path from the luminescent material to the reflective element via the third redirection element, and the reflective element may be configured to reflect luminescent material light having a wavelength in the second luminescence wavelength range (ZLR2) and comprising the second linear polarization, received by the reflective element, back to the luminescent material element via the third redirection element. Hence, recycling of light having a wavelength in the second luminescence wavelength range (ZLR2) may then be between the reflective element and the luminescent material, with the third redirection element configured in the optical path between the reflective element and the luminescent material. In embodiments, assuming an optical axis of the luminescent material light approximately under 45° to the third redirection element, at least 60%, like at least 80%, more especially at least 90%, such as at least about 95%, of the luminescent material light having a wavelength in the second luminescence wavelength range (ZLR2) and having the first polarization may be transmitted, and at least 60%, like at least 80%, more especially at 2024PF80214

[0201] 50 least 90%, such as at least about 95%, of the light of the luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) and having the second polarization, received by the third redirection element, may (a) be reflected to the reflective element, when the luminescent material light having a wavelength in the second luminescence wavelength range (XLR2) and having the second polarization propagates from the luminescent material to the third redirection element, or (b) be reflected back to the luminescent material, when the luminescent material light having a wavelength in the second luminescence wavelength range (ZLR2) and having the second polarization propagates (after reflection) from the reflective element to the third redirection element.

[0202] In addition or alternative to the luminescent material light and / or the second device light, it may be desirable to add a further type of light. For instance, by combining luminescent material light and the second device light and another type of light, white light with a relatively high CRI may be produced, or yet another color of (system) light may be provided.

[0203] Hence, in embodiments the light generating system may further comprise a third light generating device configured to generate third device light. In embodiments, the third light generating device may comprise a solid-state light source selected from the group of diode lasers, superluminescent diodes, and multi -junction diodes.

[0204] In specific embodiments, the third device light may have a third peak wavelength (Ap3) in the 380-490 nm wavelength range. More especially, the third device light may have a third peak wavelength (Zp3 ) in the 430-490 nm wavelength range.

[0205] The third device light may be included in the system light in a similar way as the second device light. Hence, the third device light may also be diffused with a diffuser arrangement. The third device light may then also be added via a polarizing beam splitter. Therefore, in embodiments the optics may be configured to direct the (diffuse) third device light in an optical path to the light exit. Yet, in embodiments the optics may comprise a (second) polarizing beam splitter.

[0206] Hence, in specific embodiments in an operational mode of the light generating system the system light may be white light comprising two or more, more especially three or more, yet even more especially all of (a) at least part of the luminescent material light having a wavelength in the first luminescence wavelength range (ZLR1), (b) at least part of the luminescent material light having a wavelength in the second luminescence wavelength range (ZLR2) and comprising the first linear polarization, (c) at least part of the diffused second device light comprising the second linear polarization, and (d) at least part of the third device 2024PF80214

[0207] 51 light. Further, in (such) embodiments the system light in this operational mode may have a correlated color temperature selected from the range of 1500-12000 K and / or a color rendering index of at least 75, such as at least 80. For instance, the CCT may be selected from the range of 1800-10000 K.

[0208] In embodiments, instead of the second light generating device and a separate third light generating device, the afore described second light generating device may be comprised by an arrangement comprising the second light generating device and a third light generating device. For the third light generating device may be referred to the above, but in embodiments, the third light generating device may especially be configured to generate third device light. Further, in specific embodiments the third device light has a third peak wavelength (Xp3 ) in the 380-490 nm wavelength range. Yet, especially the third light generating device may comprise a solid-state light source selected from the group of diode lasers, superluminescent diodes, and multi -junction diodes. Especially, in embodiments the arrangement of the second light generating device and a third light generating device may be configured upstream of the second redirection element. Further, in embodiments the light generating system may be configured such that the second device light and the third device light received by second redirection element may comprise device light comprising the same linear polarization. In specific embodiments, in an operational mode of the light generating system, the system light may be white light comprising two or more, more especially three or more, yet even more especially all of (a) at least part of the luminescent material light having a wavelength in the first luminescence wavelength range (ZLR1), (b) at least part of the luminescent material light having a wavelength in the second luminescence wavelength range (ZLR2) and comprising the first linear polarization, (c) at least part of the diffused second device light comprising the second linear polarization, and (d) at least part of the third device light; wherein the system light in this operational mode has a correlated color temperature selected from the range of 1500-12000 K a color rendering index of at least 75, such as at least 80. For instance, the CCT may be selected from the range of 1800-10000 K.

[0209] Hence, in embodiments the light generating system may be configured such that two or more of the first light generating device, the second light generating device, and the third light generating device may be operated in the first operational mode of the light generating system in a pulsed mode with pulse frequencies of 50 Hz or larger.

[0210] Further light generating devices may also be possible. Further, dependent upon the spectral power distributions, device light of the optional third light generating device and 2024PF80214

[0211] 52 optional further light generating devices may be introduced in an optical path to the light exit via a polarizing beam splitter or a multichroic beam splitter (or a combination thereof).

[0212] A dichroic beam splitter or beam combiner may in embodiments be configured combine two different types of light, e.g. light having wavelengths below a predefined XI and light having wavelengths above the predefined XI . A trichroic beam splitter may in embodiments be configured combine three different types of light, e.g. light having a wavelength below a predefined XI and light having wavelengths above the predefined XI but below another predefined wavelength X2, and light having a wavelength above the other predefined X2. Hence, the terms “multichroic beam splitter” or “multichroic beam combiner”, or similar terms, are herein used, to indicated that in embodiments two types or more than two types of light may be combined. Note that multichroic beam combiners, able to combine more than two beams of light having different spectral power distributions, may also be used to combine only two beams of light having different spectral power distributions. With a multichroic beam combiner, a plurality beams of light having different spectral power distributions may be “multiplexed” (i.e. combined).

[0213] As indicated above, in embodiments, the light generating system, especially the light generating devices, may comprise laser banks. As beams of light emitted from such (multi-chip packages and / or) laser banks may comprise multiple narrow laser beams, each individual laser beam may represent a hot spot in the beam of device light. Focusing of such a beam of device light on e.g. a luminescent material may exceed the maximum tolerable local irradiance and result in damage to the luminescent material, or other materials present in the luminescent material element. Therefore, in some embodiments, homogenizing optics may be applied and may especially be configured between (relative to the propagation of light through the system) the light generating devices (contributing to irradiation of the luminescent material) and collimating optics of the luminescent material, see also below. Similarly, in some embodiments, homogenizing optics may be applied and may especially be configured between (relative to the propagation of light through the system) the light generating devices (contributing to irradiation of the diffuser) and collimating optics of the diffuser, see also below. In embodiments, the homogenizing optics may e.g. comprise one or more of a transmissive volume diffuser, a transmissive surface diffuser, a reflective surface diffuser, a transmissive or reflective diffractive optical element, a transmissive holographic optical element, a single multi lens array, a double multi lens array such as a fly-eye lens array, or an integrating polygonal light pipe that may be either solid (with propagation in the 2024PF80214

[0214] 53 integrator based on total internal reflection) or hollow (with propagation in the integrator based on specular reflection).

[0215] In embodiments, the condensing optics may comprise a first condensing optics configured (directly) upstream of the luminescent material element and a second condensing optics configured (directly) upstream of the diffuser (arrangement). Especially, in embodiments, the first condensing optics and the second condensing optics may each comprise at least one positive lens. In specific embodiments (such as e.g. when the luminescent material element is configured in the reflective mode) the first condensing optics may comprise a first positive lens and a second smaller positive lens. In such embodiments, the smaller positive lens may especially be located between (relative to the propagation of light through the system) the first positive lens and the luminescent material element or diffuser (arrangement), respectively. Further, in embodiments, the optics may comprise a first collecting and collimating optics configured (directly) downstream of the luminescent material element and a second collecting and collimating optics configured (directly) downstream of the diffuser (arrangement). Especially, in embodiments, the first collecting and collimating optics and the second collecting and collimating optics may each comprise at least one positive lens, especially at least two positive lenses. In embodiments, the collimating optics and / or condensing optics, especially the lenses, may comprise glass materials, such as e.g. N-BK7, H-K51, B270, or fused silica (FS). The latter shows relatively low absorption and relatively low induced stress, but also has a relatively low refractive index. Therefore, if FS is used for all the lenses, in embodiments, the condensing optics for the reflective mode may preferably comprise three lenses.

[0216] The term “light source” may in principle relate to any light source known in the art. In a specific embodiment, the light source comprises a solid state LED light source (such as an LED or laser diode (or “diode laser”)). The term “light source” may also relate to a plurality of light sources, such as 2-2000 (solid state) LED light sources. Hence, the term LED may also refer to a plurality of LEDs.

[0217] Further, the term “light source” may in embodiments also refer to a so-called chips-on-board (COB) light source. The term “COB” especially refers to LED chips in the form of a semiconductor chip that is neither encased nor connected but directly mounted onto a substrate, such as a PCB. Hence, a plurality of light emitting semiconductor light source may be configured on the same substrate. In embodiments, a COB is a multi LED chip configured together as a single lighting module. 2024PF80214

[0218] 54

[0219] The term “light source” may also refer to a chip scaled package (CSP). A CSP may comprise a single solid state die with provided thereon a luminescent material comprising layer. The term “light source” may also refer to a midpower package. A midpower package may comprise one or more solid state die(s). The die(s) may be covered by a luminescent material comprising layer. The die dimensions may be equal to or smaller than 2 mm, such as in the range of e.g. 0.2-2 mm. Hence, in embodiments the light source comprises a solid state light source. Further, in specific embodiments, the light source comprises a chip scale packaged LED. Herein, the term “light source” may also especially refer to a small solid state light source, such as having a mini size or micro size. For instance, the light sources may comprise one or more of mini LEDs and micro LEDs. Especially, in embodiment the light sources comprise micro LEDs or “microLEDs” or “pLEDs”. Herein, the term mini size or mini LED especially indicates to solid state light sources having dimensions, such as die dimension, especially length and width, selected from the range of 100 pm - 1 mm. Herein, the term p size or micro LED especially indicates to solid state light sources having dimensions, such as die dimension, especially length and width, selected from the range of 100 pm and smaller.

[0220] The light source may have a light escape surface. For LED’s it may for instance be the LED die, or when a resin is applied to the LED die, the outer surface of the resin. In principle, it may also be the terminal end of a fiber. The term escape surface especially relates to that part of the light source, where the light actually leaves or escapes from the light source. The light source is configured to provide a beam of light. This beam of light (thus) escapes from the light exit surface of the light source.

[0221] Likewise, a light generating device may comprise a light escape surface, such as an end window. Further, likewise a light generating system may comprise a light escape surface, such as an end window.

[0222] The term “light source” may refer to a semiconductor light-emitting device, such as a light emitting diode (LEDs), a resonant cavity light emitting diode (RCLED), a vertical cavity laser diode (VCSELs), an edge emitting laser, etc. The term “light source” may also refer to an organic light-emitting diode (OLED), such as a passive-matrix (PMOLED) or an active-matrix (AMOLED). In a specific embodiment, the light source comprises a solid-state light source (such as an LED or laser diode). In an embodiment, the light source comprises an LED (light emitting diode). The terms “light source” or “solid state light source” may also refer to a superluminescent diode (SLED). 2024PF80214

[0223] 55

[0224] The term “light source” may also relate to a plurality of (essentially identical (or different)) light sources, such as 2-2000 solid state light sources. In embodiments, the light source may comprise one or more micro-optical elements (array of micro lenses) downstream of a single solid-state light source, such as an LED, or downstream of a plurality of solid-state light sources (i.e. e.g. shared by multiple LEDs). In embodiments, the light source may comprise an LED with on-chip optics. In embodiments, the light source comprises pixelated single LEDs (with or without optics) (offering in embodiments on-chip beam steering).

[0225] In embodiments, the light source may be configured to provide primary radiation, which is used as such, such as e.g. a blue light source, like a blue LED, or a green light source, such as a green LED, and a red light source, such as a red LED. Such LEDs, which may not comprise a luminescent material (“phosphor”) may be indicated as direct color LEDs.

[0226] The light source may especially be configured to generate light source light having an optical axis (O), (a beam shape,) and a spectral power distribution. The light source light may in embodiments comprise one or more bands, e.g. having band widths as known for lasers.

[0227] The term “light source” may (thus) refer to a light generating element as such, like e.g. a solid state light source, or e.g. to a package of the light generating element, such as a solid state light source, and one or more of a luminescent material comprising element and (other) optics, like a lens, a collimator. A light converter element (“converter element” or “converter”) may comprise a luminescent material comprising element. For instance, a solid state light source as such, like a blue LED, is a light source. A combination of a solid state light source (as light generating element) and a light converter element, such as a blue LED and a light converter element, optically coupled to the solid state light source, may also be a light source (but may also be indicated as light generating device). Hence, a white LED is a light source (but may e.g. also be indicated as (white) light generating device).

[0228] The term “light source” herein may also refer to a light source comprising a solid state light source, such as an LED or a laser diode or a superluminescent diode.

[0229] The term “light source” may (thus) in embodiments also refer to a light source that is (also) based on conversion of light, such as a light source in combination with a luminescent converter material. Hence, the term “light source” may also refer to a combination of an LED with a luminescent material configured to convert at least part of the 2024PF80214

[0230] 56

[0231] LED radiation, or to a combination of a (diode) laser with a luminescent material configured to convert at least part of the (diode) laser radiation.

[0232] In embodiments, the term “light source” may also refer to a combination of a light source, like an LED, and an optical filter, which may change the spectral power distribution of the light generated by the light source. Especially, the term “light generating device” may be used to address a light source and further (optical components), like an optical filter and / or a beam shaping element, etc.

[0233] The phrases “different light sources” or “a plurality of different light sources”, and similar phrases, may in embodiments refer to a plurality of solid-state light sources selected from at least two different bins. Likewise, the phrases “identical light sources” or “a plurality of same light sources”, and similar phrases, may in embodiments refer to a plurality of solid-state light sources selected from the same bin.

[0234] The term “solid state light source”, or “solid state material light source”, and similar terms, may especially refer to semiconductor light sources, such as a light emitting diode (LED), a diode laser, or a superluminescent diode.

[0235] The term “laser light source” especially refers to a laser. Such laser may especially be configured to generate laser light source light having one or more wavelengths in the UV, visible, or infrared, especially having a wavelength selected from the spectral wavelength range of 200-2000 nm, such as 300-1500 nm. The term “laser” especially refers to a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. Especially, in embodiments the term “laser” may refer to a solid-state laser. In specific embodiments, the terms “laser” or “laser light source”, or similar terms, refer to a laser diode (or diode laser).

[0236] Hence, in embodiments the light source comprises a laser light source. In embodiments, the terms “laser” or “solid state laser” or “solid state material laser” may refer to one or more of cerium doped lithium strontium (or calcium) aluminum fluoride (Ce:LiSAF, Ce:LiCAF), chromium doped chrysoberyl (alexandrite) laser, chromium ZnSe (CrZnSe) laser, divalent samarium doped calcium fluoride (Sm:CaF2) laser, Er:YAG laser, erbium doped and erbium-ytterbium codoped glass lasers, F-Center laser, holmium YAG (Ho: YAG) laser, Nd:YAG laser, NdCrYAG laser, neodymium doped yttrium calcium oxoborate Nd:YCa4O(BO3)3 or Nd:YCOB, neodymium doped yttrium orthovanadate (Nd:YVO4) laser, neodymium glass (Nd:glass) laser, neodymium YLF (Nd:YLF) solid-state laser, promethium 147 doped phosphate glass (147Pm3+:glass) solid-state laser, ruby laser (AhO3:Cr3+), thulium YAG (Tm:YAG) laser, titanium sapphire (Ti:sapphire; AhO3:Ti3+) 2024PF80214

[0237] 57 laser, trival ent uranium doped calcium fluoride (U:CaF2) solid-state laser, Ytterbium doped glass laser (rod, plate / chip, and fiber), Ytterbium YAG (Yb:YAG) laser, Yb2Os (glass or ceramics) laser, etc. For instance, including second and third harmonic generation embodiments, the light source may comprise one or more of an F center laser, an yttrium orthovanadate (Nd:YVO4) laser, a promethium 147 doped phosphate glass (147Pm3+:glass), and a titanium sapphire (Ti:sapphire; AhChYi3) laser. For instance, considering second and third harmonic generation, such light sources may be used to generated blue light.

[0238] In embodiments, the terms “laser” or “solid state laser” or “solid state material laser” may refer to one or more of a semiconductor laser diodes, such as GaN, InGaN, AlGalnP, AlGaAs, InGaAsP, lead salt, vertical cavity surface emitting laser (VCSEL), quantum cascade laser, hybrid silicon laser, etc. Suitable solid state lasers may be selected from (III-V compound) semiconductor lasers, such as in specific embodiments semiconductor lasers selected from the group of GaN, AlGaN, InGaN, and AlGalnN, (especially for blue-green), GaP, InP, GalnP, and AlGalnP (especially for red-NIR), GaAs, AlGaAs, InGaAs, and InGaAsP (especially for NIR-MIR). Hence, in embodiments one or more of the light generating devices may comprise a semiconductor laser selected from the group of GaN, AlGaN, InGaN, AlGalnN, GaP, InP, GalnP, and AlGalnP lasers.

[0239] A laser may be combined with an upconverter in order to arrive at shorter (laser) wavelengths. For instance, with some (trival ent) rare earth ions upconversion may be obtained or with non-linear crystals upconversion can be obtained. Alternatively, a laser can be combined with a downconverter, such as a dye laser, to arrive at longer (laser) wavelengths.

[0240] As can be derived from the below, the term “laser light source” may also refer to a plurality of (different or identical) laser light sources. In specific embodiments, the term “laser light source” may refer to a plurality N of (identical) laser light sources. In embodiments, N=2, or more. In specific embodiments, N may be at least 5, such as especially at least 8. In this way, a higher brightness may be obtained. In embodiments, laser light sources may be arranged in a laser bank (see also above). The laser bank may in embodiments comprise heat sinking and / or optics e.g. a lens to collimate the laser light. Hence, in embodiments lasers in a laser bank (or “laser array bank”) may share the same optics.

[0241] The laser light source is configured to generate laser light source light (or “laser light”). The light source light may essentially consist of the laser light source light. The light source light may also comprise laser light source light of two or more (different or 2024PF80214

[0242] 58 identical) laser light sources. For instance, the laser light source light of two or more (different or identical) laser light sources may be coupled into a light guide, to provide a single beam of light comprising the laser light source light of the two or more (different or identical) laser light sources. In specific embodiments, the light source light is thus especially collimated light source light. In yet further embodiments, the light source light is especially (collimated) laser light source light.

[0243] The laser light source light may in embodiments comprise one or more bands, having band widths as known for lasers. In specific embodiments, the band(s) may be relatively sharp line(s), such as having full width half maximum (FWHM) in the range of less than 20 nm at RT, such as equal to or less than 10 nm. Hence, the light source light has a spectral power distribution (intensity on an energy scale as function of the wavelength) which may comprise one or more (narrow) bands.

[0244] The beams (of light source light) may be focused or collimated beams of (laser) light source light. The term “focused” may especially refer to converging to a small spot. This small spot may be at the discrete converter region, or (slightly) upstream thereof or (slightly) downstream thereof. Especially, focusing and / or collimation may be such that the cross-sectional shape (perpendicular to the optical axis) of the beam at the discrete converter region (at the side face) is essentially not larger than the cross-section shape (perpendicular to the optical axis) of the discrete converter region (where the light source light irradiates the discrete converter region). Focusing may be executed with one or more optics, like (focusing) lenses. Especially, two lenses may be applied to focus the laser light source light. Collimation may be executed with one or more (other) optics, like collimation elements, such as lenses and / or parabolic mirrors. In embodiments, the beam of (laser) light source light may be relatively highly collimated, such as in embodiments <2° (FWHM), more especially <1° (FWHM), most especially <0.5° (FWHM). Hence, <2° (FWHM) may be considered (highly) collimated light source light. Optics may be used to provide (high) collimation (see also above).

[0245] The term “solid state material laser”, and similar terms, may refer to a solid state laser like based on a crystalline or glass body doped with ions, like transition metal ions and / or lanthanide ions, to a fiber laser, to a photonic crystal laser, to a semiconductor laser, such as e.g. a vertical cavity surface-emitting laser (VCSEL), etc.

[0246] The term “solid state light source”, and similar terms, may especially refer to semiconductor light sources, such as a light emitting diode (LED), a laser diode, or a superluminescent diode. Instead of the term “solid state light source” also the term 2024PF80214

[0247] 59

[0248] “semiconductor-based light source” may be applied. Hence, the term “semiconductor-based light source” may e.g. refer to one or more of a light emitting diode (LED), a laser diode, and a superluminescent diode. Hence, the light generating device may comprise one or more of a light emitting diode (LED), a laser diode, and a superluminescent diode.

[0249] A light-emitting diode (LED) is especially a semiconductor light source that emits light when current flows through it. Electrons in the semiconductor may recombine with electron holes, releasing energy in the form of photons. The color of the light (corresponding to the energy of the photons) may be determined by the energy required for electrons to cross the band gap of the semiconductor.

[0250] A laser diode (or diode laser) may be a semiconductor device substantially similar to a light-emitting diode in which a diode pumped directly with electrical current can create lasing conditions at the diode's junction. This is known to a person skilled in the art.

[0251] Superluminescent diodes are known in the art. A superluminescent diode may be indicated as a semiconductor device which may be able to emit low-coherence light of a broad spectrum like an LED, while having a brightness about in between the brightness of LEDs and laser diodes. Superluminescent diodes are e.g. described in US2020192017, incorporated herein by reference, or in “Edge Emitting Laser Diodes and Superluminescent Diodes”, Szymon Stanczyk, Anna Kafar, Dario Schiavon, Stephen Naj da, Thomas Slight, Piotr Perlin, Book Editor(s): Fabrizio Roccaforte, Mike Leszczynski, First published: 03 August 2020 https: / / doi.org / 10.1002 / 9783527825264.ch9 in chapter 9,3 superluminescent diodes. This book, and especially chapter 9.3, are herein incorporated by reference. Superluminescent diodes may combine the high power and brightness of laser diodes with the low coherence of conventional light-emitting diodes. The low (temporal) coherence of the source has advantages that the speckle is significantly reduced or not visible, and the spectral distribution of emission is much broader compared to laser diodes, which can be better suited for lighting applications. Hence, in embodiments, the solid state light source may comprise a superluminescent diode. For instance, in further specific embodiments, the solid state light source may comprise a GaN-based superluminescent diode, or an InGaN-based superluminescent diode, or an AlGaN-based superluminescent diode.

[0252] The light generating system may be part of or may be applied in e.g. office lighting systems, household application systems, shop lighting systems, home lighting systems, accent lighting systems, spot lighting systems, theater lighting systems, fiber-optics application systems, projection systems, self-lit display systems, pixelated display systems, segmented display systems, warning sign systems, medical lighting application systems, 2024PF80214

[0253] 60 indicator sign systems, decorative lighting systems, portable systems, automotive applications, (outdoor) road lighting systems, urban lighting systems, green house lighting systems, horticulture lighting, digital projection, or LCD backlighting. The light generating system (or luminaire) may be part of or may be applied in e.g. optical communication systems or disinfection systems.

[0254] The term “white light”, and similar terms, herein, is known to the person skilled in the art. It may especially relate to light having a correlated color temperature (CCT) between about 1800 K and 20000 K, such as between 2000 and 20000 K, especially 2700- 20000 K, for general lighting especially in the range of about 2000-7000 K, such as in the range of 2700 K and 6500 K. In embodiments, e.g. for backlighting purposes, or for other purposes, the correlated color temperature (CCT) may especially be in the range of about 7000 K and 20000 K. Yet further, in embodiments the correlated color temperature (CCT) is especially within about 15 SDCM (standard deviation of color matching) from the BBL (black body locus), especially within about 10 SDCM from the BBL, even more especially within about 5 SDCM from the BBL. In specific embodiments, the correlated color temperature (CCT) may be selected from the range of 6000-12000 K, like selected from the range of 7000-12000 K, like at least 8000 K. Yet further, in embodiments the correlated color temperature (CCT) may be selected from the range of 6000-12000 K, like selected from the range of 7000-12000 K, in combination with a CRI of at least 70.

[0255] The terms “visible”, “visible light” or “visible emission” and similar terms refer to light having one or more wavelengths in the range of about 380-780 nm. Herein, UV may especially refer to a wavelength selected from the range of 190-380 nm, such as 200-380 nm. The terms “light” and “radiation” are herein interchangeably used, unless clear from the context that the term “light” only refers to visible light. The terms “light” and “radiation” may thus refer to UV radiation, visible light, and IR radiation. In specific embodiments, especially for lighting applications, the terms “light” and “radiation” refer to (at least) visible light.

[0256] Herein, when an element is indicated to be transmissive this may in embodiments imply that at one or more wavelengths the part of the radiation that is transmitted may be larger than the part of the radiation that is reflected or absorbed. Herein, when an element is indicated to be reflective this may in embodiments imply that at one or more wavelengths the part of the radiation that is reflected may be larger than the part of the radiation that is transmitted or absorbed. The term “transmissive” with regards to the light incident on the transmissive element may herein may especially refer to at least 50% of 2024PF80214

[0257] 61 incident light passing through the material, such as at least 60%, especially at least 70%, such as at least 80%, especially at least 90%, such as at least 95%, under perpendicular irradiation or other predefined angle of incidence. Similarly, the term “reflective” with regards to the light source light may herein refer to at least 50% of incident light source light being reflected, such as at least 60%, especially at least 70%, such as at least 80%, especially at least 90%, such as at least 95%, under perpendicular irradiation or other predefined angle of incidence. Here, the percentages may refer to percentages based on Watts. Hence, the term “transmissive” may thus imply that at least part of the (incident) light is transmitted. Likewise, the term “reflective” may thus imply that at least part of the (incident) light is reflected.

[0258] In yet a further aspect, the invention also provides a lamp or a luminaire comprising the light generating system as defined herein. The luminaire may further comprise a housing, optical elements, louvres, etc. etc... The lamp or luminaire may further comprise a housing enclosing the light generating system. The lamp or luminaire may comprise a light window in the housing or a housing opening, through which the system light may escape from the housing. In yet a further aspect, the invention also provides a projection device comprising the light generating system as defined herein. Especially, a projection device or “projector” or “image projector” may be an optical device that projects an image (or moving images) onto a surface, such as e.g. a projection screen. The projection device may include one or more light generating systems such as described herein. Hence, in an aspect the invention also provides a lighting device selected from the group of a lamp, a luminaire, a projector device, a disinfection device, a photochemical reactor, and an optical wireless communication device, comprising the light generating system as defined herein. The lighting device may comprise a housing or a carrier, configured to house or support, one or more elements of the light generating system. For instance, in embodiments the lighting device may comprise a housing or a carrier, configured to house or support one or more of first light generating device, second light generating device, the luminescent material element, one or more of the optical elements, etc. In (other) embodiments, the lamp may be a torch.

[0259] In yet a further aspect, the invention also provides a lighting fixture comprising the light generating system as defined herein. Hence, in yet a further aspect, the light generating system may comprise a device selected from the group of a lamp, a luminaire, or a lighting fixture, wherein the lamp, luminaire, or lighting fixture may comprise one or more elements of the light generating system, such as the first light generating device, 2024PF80214

[0260] 62 second light generating device, the luminescent material element, one or more of the optical elements, etc., and the light generating system may further comprise e.g. a control system configured to control the device.

[0261] The term “lighting fixture” may refer to a light emitting system like a moving head, a search light, a stage light, etc. Generally these fixtures may have various control options for changing one or more of the direction of the light (e.g. via gimbals or rotary stages), the beam angle / width (e.g. via zoom optics), the beam pattern (e.g. via mechanical selection of a specific aperture that defines a virtual and patterned source for the further projection optics), the color of the light (e.g. via mechanical selection of a certain color filter), and of course the luminous flux, and mostly these are remotely controllable.

[0262] BRIEF DESCRIPTION OF THE DRAWINGS

[0263] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which: Figs, la-ld schematically depict several aspects of the invention in relation to spectral power distributions; Figs. 2a-2c schematically depict a non-limiting number of embodiments of the system; and Fig. 3 schematically depicts a number of (application) embodiments. The schematic drawings are not necessarily to scale.

[0264] DETAILED DESCRIPTION OF THE EMBODIMENTS

[0265] Fig. la schematically depicts power distributions with the y-axis being an energy related axis (like e.g. Watt / nm), i.e. the spectral power, and with the x-axis displaying the wavelength in nanometers. In Fig. la a number of embodiments are displayed in a single drawing, though they are not necessarily applied in this way and as this combination herein.

[0266] The peak with peak wavelength pi refers to first device light 111, which may pump a luminescent material. The luminescent material may convert at least part of the first device light 111 into luminescent material light 201. In at least part of a first luminescence wavelength range (ZLR1) and in at least part of a second luminescence wavelength range (ZLR2) the luminescent material light 201 may have (non-zero) spectral power. The luminescent material light 201 in the first luminescence wavelength range (ZLR1) is indicated with reference 201a, and the luminescent material light 201 in the second luminescence wavelength range ZLR1 is indicated with reference 201b. The peak with peak wavelength L>2 refers to second device light 121. Especially, in at least part of a second device light wavelength range (ZDR2) the second device light 121 may have spectral power. 2024PF80214

[0267] 63

[0268] Here, the second device light wavelength range (XDR2) and the second luminescence wavelength range (XLR2) at least partly overlap. Further, Fig. la also schematically depicts an embodiment of third device light 131 having a third peak wavelength ki>3 (see further also below).

[0269] In Fig. la, the luminescence wavelength ranges (ZLR1, ZLR2) and device light wavelength ranges (ZDR1, ZDR2, and ZDR3) are selected such, that they are the narrowest wavelength ranges that (together) include the wavelengths of the luminescent material light, or the device light, respectively, providing at least 99%, more especially at least 99.9% of the spectral power (especially 100% of the spectral power).

[0270] Preceding to the schematically depicted embodiments of the system in Figs. 2a-2c, Figs, lb, 1c, and Id schematically depict how a spectral power distribution of the system light 1001 may look like after direction of the luminescent material light 201 via the first redirection element 510 (see below).

[0271] Referring to Fig. lb, on the left, only the luminescent material light 201 is shown, with the first luminescence wavelength range (ZLR1) comprising unpolarized luminescent material light 201a and the second luminescence wavelength range (ZLR2) comprising first linear polarized light luminescent material light 201b. The spectral power on the right may show a dip relative to the spectral power on the left, as some of the luminescent material light 201 in the second luminescence wavelength range (ZLR2) may be lost as not all light may be 100% recycled (see also below and above about recycling). On the right in Fig. lb, it is shown that this luminescent material light 201 may be combined with second device light 121, which may have a complementary second linear polarization (here thus by way of example p-polarization), via a second redirection element 520 (see below). Here, by way of example two peaks are shown, as one or more (different) types of second device light 121 may be added. Hence, here the long wavelength part (red) may be polarized.

[0272] Here, u refers to unpolarized and s refers to s-polarized (however, this may also be p-polarized; s-polarization is only used as an example, but is in line with the p- polarized second device light 121).

[0273] Fig. 1c schematically depicts a similar embodiment. However, now the second luminescence wavelength range (ZLR2) is at another position than in Fig. lb, somewhere in the middle of the emission band of the luminescent material. At the short wavelength side, the first luminescence wavelength range (ZLR1) may be positioned; at the long wavelength side, another first luminescence wavelength range (ZLR1) may be positioned, which may also be indicated as third luminescence wavelength range. The former is also indicated with 2024PF80214

[0274] 64 reference 201a’ and the latter is also indicated with reference 201a”. Hence, here the green wavelength part may be polarized, which is here also indicated with reference 201b. Again, on the left Fig. 1c schematically depicts the emission from the phosphor after direction of the luminescent material light 201 via the first redirection element 510 (see below), and on the right Fig. 1c schematically depicts the emission from the phosphor after direction of the luminescent material light 201 via the first redirection element 510 and after getting combined with the p-polarized green via the second redirection element 520 (see below).

[0275] Fig. Id schematically depicts an embodiment wherein a green part and a red part are polarized. This would allow adding device light of different types of light generating devices (i.e. in the green and in the red, respectively). The unpolarized parts are the wavelength ranges indicated with references 201a’, 201a”, and 201a””; the polarized parts are the wavelength ranges indicated with references 201b’ and 201b”.

[0276] The embodiments of Figs, la and lb may e.g. be obtained with the systems 1000 described below. The embodiments of Figs. 1c and Id may require further optics (and light generating devices).

[0277] Referring to Figs. 2a-2c, in specific embodiments, the invention provides a light generating system 1000 comprising a first light generating device 110, a second light generating device 120, a luminescent material element 2000, optics 500, and a light exit 1090. Moreover, in embodiments, the first light generating device 110 may be configured to generate first device light 111. Especially, the first device light 111 may have a first peak wavelength (kp l ) selected from the wavelength range of 380-490 nm. In further embodiments, the first light generating device 110 may comprise a solid-state light source selected from the group of diode lasers, superluminescent diodes, and multi -junction diodes. Furthermore, in embodiments, the luminescent material element 2000 may comprise a luminescent material 200. In further embodiments, the luminescent material 200 may be configured to convert at least part of the first device light 111 received by the luminescent material element 2000 into luminescent material light 201. Furthermore, in embodiments, the second light generating device 120 may be configured to generate second device light 121. In further embodiments, the second light generating device 120 may comprise a solid-state light source selected from the group of diode lasers, superluminescent diodes, and multi -junction diodes. The first light generating device 110, the second light generating device 120 (and also the third light generating device 130), may herein also be indicated with the general reference 100, indicating a light generating device. 2024PF80214

[0278] 65

[0279] Furthermore, in embodiments, the optics 500 may comprise redirection elements 510,520,530, and a diffuser arrangement 1700. Especially, a first redirection element 510 and a third redirection element 530 may be configured in an optical path between the first light generating device 110 and the luminescent material element 2000. In further embodiments, the first redirection element 510 may be configured to direct (such as transmit) at least part of the first device light 111 received by the first redirection element 510 to the luminescent material element 2000 via the third redirection element 530. In further embodiments, the third redirection element 530 may be (a) transmissive for first device light 111, received by the third redirection element 530, (b) transmissive for luminescent material light 201 having a wavelength in the first luminescence wavelength range (XLR1), received by the third redirection element 530, (c) transmissive for luminescent material light 201 having a wavelength in the second luminescence wavelength range (XLR2) comprising a first linear polarization, received by the third redirection element 530, and (d) reflective for luminescent material light 201 having a wavelength in the second luminescence wavelength range (XLR2) and comprising a second linear polarization, different from the first linear polarization, received by the third redirection element 530 (which may thus be polarization based). Furthermore, in embodiments, the optics 500 (comprising the third polarization based redirection element 530) may be configured such that at least part of the luminescent material light 201 having a wavelength in the second luminescence wavelength range (XLR2) and comprising the second linear polarization may be directed back to the luminescent material element 2000. In further embodiments, the first redirection element 510 may be configured to direct (a) luminescent material light 201 having a wavelength in the first luminescence wavelength range (XLR1), and (b) luminescent material light 201 having a wavelength in the second luminescence wavelength range (XLR2) and comprising the first linear polarization, received by the first redirection element 510, in an optical path to the light exit 1090, via a second redirection element 520. Especially, the diffuser arrangement 1700 may comprise a retarder element 550 and a polarization maintaining diffuser 710. In further embodiments, the retarder element 550 may comprise a / 4 plate. Further, in embodiments, the second redirection element 520 and the retarder element 550 may be configured in an optical path between the second light generating device 120 and the polarization maintaining diffuser 710; the light generating system 1000 may be configured such that second device light 121 received by the second redirection element 520 may comprise the first linear polarization. Furthermore, in embodiments, the second redirection element 520 may be configured to direct second device light 121 comprising the first linear polarization, received by the second 2024PF80214

[0280] 66 redirection element 520, in an optical path to the diffuser arrangement 1700. Especially, the diffuser arrangement 1700 may be configured to convert second device light 121 comprising the first linear polarization, received by the diffuser arrangement 1700, into diffused second device light 121 comprising the second linear polarization. Moreover, in embodiments, the second redirection element 520 may be configured to direct (a) luminescent material light 201 having a wavelength in the first luminescence wavelength range (XLR1) (received via the first redirection element 510), (b) luminescent material light 201 having a wavelength in the second luminescence wavelength range (XLR2) and comprising the first linear polarization (received via the first redirection element 510), and (c) diffused second device light 121 comprising the second linear polarization, received by the second redirection element 520, into an optical path to the light exit 1090. In further embodiments, the light generating system 1000 may be configured to generate system light 1001 comprising, (in an operational mode of the light generating system 1000,) one or more of (a) at least part of the luminescent material light 201 having a wavelength in the first luminescence wavelength range (XLR1), (b) at least part of the luminescent material light 201 having a wavelength in the second luminescence wavelength range (XLR2) and comprising the first linear polarization, and (c) at least part of the diffused second device light 121 comprising the second linear polarization. This contributions to the system light 1001 are also indicated at the light exit 1090.

[0281] Moreover, in embodiments, the light generating system 1000 may be configured such that at least part of the luminescent material light 201 having a wavelength in the second luminescence wavelength range (XLR2) and comprising the second linear polarization that may be received by the luminescent material element 2000 after having been directed back thereto, may be converted into further luminescent material light 201 having a wavelength in a second luminescence wavelength range (ZLR2) and comprising the first linear polarization). This is depicted by the luminescent material light 201b returning to the luminescent material 200. This light may be scattered by the luminescent material 200, leading to the generation of at least part of the luminescent material light 201 having a wavelength in a second luminescence wavelength range (ZLR2) and having the first linear polarization).

[0282] In further embodiments, the light generating system 1000 may be configured such that the first light generating device 110 and the second light generating device 120 may be operated in the first operational mode of the light generating system 1000 in a pulsed mode with pulse frequencies of 50 Hz or larger. 2024PF80214

[0283] 67

[0284] Moreover, in embodiments, in the first luminescence wavelength range (XLR1) the luminescent material light 201 may have a first spectral power Pl. Further, in embodiments, in the second luminescence wavelength range (XLR2) the luminescent material light 201 may have a second spectral power P2. Moreover, in embodiments, 0.05<P2 / Pl<0.5; see e.g. also Figs, la-lb.

[0285] Further, in embodiments, the second luminescence wavelength range (XLR2) and the second device light wavelength range (XDR2) may (at least partially overlap, more especially) overlap over a range of at least 10 nm (such as at least 20 nm, like at least 30 nm); see e.g. also Figs, la-ld.

[0286] Alternatively, in embodiments, the second luminescence wavelength range (kLR.2) and the second device light wavelength range (ZDR2) may have an inter wavelength range distance of at maximum 10 nm. Such embodiments are herein not further described in detail.

[0287] In embodiments, the luminescent material 200 may comprise a single type of luminescent material or a combination of two or more different (types of) luminescent materials.

[0288] Further, in embodiments, the second luminescence wavelength range (ZLR2) and the second device light wavelength range (ZDR2) may be at least partly comprised in a wavelength range of 490-640 nm (and wherein the luminescent material light 201 may have spectral power in at least one of (a) a 490-560 nm wavelength range and (b) a 560-640 nm wavelength range). Yet, in embodiments, the second device light 121 may have a second peak wavelength (Ap2) in the green-yellow wavelength range, and in other embodiments, the second device light 121 may have a second peak wavelength (Zp2) in the yellow-red wavelength range. In embodiments, the second light generating device 120 may comprise one or more semiconductor lasers. Further, in embodiments the second light generating device 120 may comprise a laser bank comprising a plurality of semiconductor lasers. Likewise, the first light generating device 110 may comprise a laser bank comprising a plurality of semiconductor lasers. In specific embodiments, the second light generating device 120 may be configured to generate second device light 121 having a second peak wavelength (Zp2) in the 610-680 nm wavelength range.

[0289] Further, in embodiments, first redirection element 510 may comprise a multichroic based beam splitter (such as a dichroic) based beam splitter. In this way, first device light 111 may reach the luminescent material 200, and luminescent material light 201 2024PF80214

[0290] 68

[0291] (from the first luminescence wavelength range XLR1 (and from the second luminescence wavelength range XLR2)) may be directed in an optical pat to the light exit 1090.

[0292] Moreover, in embodiments, the second redirection element 520 may comprise a polarizing beam splitter for the second device light 121.

[0293] Yet, in embodiments, the third redirection element 530 may comprise a reflective polarizer for light in the second luminescence wavelength range (XLR2). This is schematically depicted in Fig. 2a.

[0294] Referring to Fig. 2b, in embodiments, the third redirection element 530 may comprise a polarizing beam splitter for light in the second luminescence wavelength range (XLR2). In further embodiments, the optics 500 may comprise a reflective element 540. Furthermore, in embodiments, the light generating system 1000 may be configured such that at least part of the luminescent material light 201 having a wavelength in the second luminescence wavelength range (XLR2) and comprising the second linear polarization propagates in an optical path from the luminescent material 200 to the reflective element 540 via the third redirection element 530. Yet, in embodiments, the reflective element 540 may be configured to reflect luminescent material light 201 having a wavelength in the second luminescence wavelength range (XLR2) and comprising the second linear polarization, received by the reflective element 540, back to the luminescent material element 2000 via the third redirection element 530.

[0295] Referring to Figs. 2a-2b, in embodiments, the light generating system 1000 may further comprise a third light generating device 130 configured to generate third device light 131. In further embodiments, the third device light 131 may have a third peak wavelength (Ap3) in the 380-490 nm wavelength range. Further, in embodiments, the third light generating device 130 may comprise a solid-state light source selected from the group of diode lasers, superluminescent diodes, and multi -junction diodes. Further, in embodiments, the optics 500 may be configured to direct the third device light 131 in an optical path to the light exit 1090 (wherein the optics may comprise a polarizing beam splitter 560). Especially, in an operational mode of the light generating system 1000, the system light 1001 may be white light comprising (a) at least part of the luminescent material light 201 having a wavelength in the first luminescence wavelength range (ZLR1), (b) at least part of the luminescent material light 201 having a wavelength in the second luminescence wavelength range (ZLR2) and comprising the first linear polarization, (c) at least part of the diffused second device light 121 comprising the second linear polarization, and (d) at least part of the third device light 131. In further embodiments, the system light 1001 in this 2024PF80214

[0296] 69 operational mode may have a correlated color temperature selected from the range of 1500- 12000 K and a color rendering index of at least 80. For clarity in the drawings, diffused second device light 121 is also indicated with reference 791.

[0297] Referring to Fig. 2c, in embodiments the system 1000 may comprise an arrangement 125 of the second light generating device 120 and a third light generating device 130. Especially, the third light generating device 130 may be configured to generate third device light 131. Especially, the third device light 131 may have a third peak wavelength (Zp3) in the 380-490 nm wavelength range. Moreover, in embodiments, the third light generating device 130 may comprise a solid-state light source selected from the group of diode lasers, superluminescent diodes, and multi -junction diodes. Further, in embodiments, the arrangement of the second light generating device 120 and a third light generating device 130 may be configured upstream of the second redirection element 520; the light generating system 1000 may be configured such that the second device light 121 and the third device light 131 received by second redirection element 520 may comprise device light comprising the same linear polarization. Yet, in embodiments, in an operational mode of the light generating system 1000, the system light 1001 may be white light comprising (a) at least part of the luminescent material light 201 having a wavelength in the first luminescence wavelength range (ZLR1), (b) at least part of the luminescent material light 201 having a wavelength in the second luminescence wavelength range (ZLR2) and comprising the first linear polarization, (c) at least part of the diffused second device light 121 comprising the second linear polarization, and (d) at least part of the third device light 131. Further, in embodiments, the system light 1001 in this operational mode may have a correlated color temperature selected from the range of 1500-12000 K and a color rendering index of at least 80.

[0298] Referring to Figs. 2a-2c, in further embodiments, the light generating 1000 may further comprise a control system 300. In embodiments, the control system 300 may be configured to control a spectral power distribution of the system light 1001 by individually controlling the first light generating device 110, the second light generating device 120, and the optional third light generating device 130 (and optional further light generating devices).

[0299] In Figs. 2a-2c the second redirection element 520 may have a double function, as it is in the optical path between the first redirection element 510 and the light exit 1090, and in the optical path between the second light generating device 120 and the diffuser arrangement 1700. However it may also be possible to split the functions of the second redirection element 520 and e.g. use two second redirection elements 520. However, this 2024PF80214

[0300] 70 would imply a rearrangement of some of the elements schematically depicted in Figs. 2a-2c. Referring to e.g. Fig. 2a, the diffuser arrangement 1700 and the second light generating device 120 may be configured at one side of the optical path between the first redirection element 510 and the light exit 1090. This would allow the currently drawn second redirection element 520 be indicated as a secondary second redirection element 520, which would receive the diffused second device light via a primary second redirection element 520. The latter primary second redirection element 520 would then be configured in an optical path between the second light generating device 120 and the diffuser arrangement 1700, but this optical path would not cross the optical path between the first redirection element 510 and the light exit 1090.

[0301] Hence, in embodiments (not schematically depicted herein) the system may comprise a plurality of second redirection elements 520, wherein a primary second redirection element 520 and the retarder element 550 may be configured in an optical path between the second light generating device 120 and the polarization maintaining diffuser 710. Further, the light generating system 1000 may be configured such that second device light 121 received by the primary second redirection element 520 comprises the first linear polarization. Yet, in embodiments the primary second redirection element 520 may be configured to direct second device light 121 comprising the first linear polarization, received by the second redirection element 520, in an optical path to the diffuser arrangement 1700. Further, in embodiments the diffuser arrangement 1700 may be configured to convert second device light 121 comprising the first linear polarization, received by the diffuser arrangement 1700, into diffused second device light 121 comprising the second linear polarization. Moreover, in embodiments the primary second redirection element 520 may be configured to direct diffused second device light 121 comprising the second linear polarization, received by the primary second redirection element 520, in an optical path to the secondary second redirection element 520. Yet, in embodiments the secondary second redirection element 520 may be configured to direct (a) luminescent material light 201 having a wavelength in the first luminescence wavelength range XLR1 received via the first redirection element 510, (b) luminescent material light 201 having a wavelength in the second luminescence wavelength range XLR2 and comprising the first linear polarization received via the first redirection element 510, and (c) diffused second device light 121 comprising the second linear polarization, received by the second redirection element 520 via the primary second redirection element 520, into an optical path to the light exit 1090. Yet, in embodiments the light generating system 1000 may be configured to generate system light 1001 comprising, in 2024PF80214

[0302] 71 an operational mode of the light generating system 1000, one or more of (a) at least part of the luminescent material light 201 having a wavelength in the first luminescence wavelength range XLR1, (b) at least part of the luminescent material light 201 having a wavelength in the second luminescence wavelength range XLR2 and comprising the first linear polarization, and (c) at least part of the diffused second device light 121 comprising the second linear polarization.

[0303] Further, note that the diffuser arrangement 1700, such as from the schematically depicted embodiments in Figs. 2a-2c may also be optional. In such embodiments, referring again to these schematical drawings, the second redirection element 520 may then be rotated 90°. This would still allow the luminescent material light 201, received by the second redirection element 520 via the first redirection element 510, to be directed in an optical path to the light exit 1090, and would allow second device light 121, received by the second redirection element 520, to be directed in an optical path to the light exit 1090.

[0304] Hence, in embodiments (not schematically depicted herein) the light generating system 1000 may comprise a first light generating device 110, a second light generating device 120, a luminescent material element 2000, optics 500, and a light exit 1090. Especially, the first light generating device 110 may (thus) be configured to generate first device light 111, wherein the first device light 111 may have a first peak wavelength kp l selected from the wavelength range of 380-490 nm. Further, as indicated above, the first light generating device 110 may comprise a solid-state light source selected from the group of laser diodes, superluminescent diodes, and multi -junction diodes. Yet, the luminescent material element 2000 may comprise a luminescent material 200. Especially, the luminescent material 200 may be configured to convert at least part of the first device light 111 received by the luminescent material element 2000 into luminescent material light 201. In embodiments, in at least part of a first luminescence wavelength range ZLR I and in at least part of a second luminescence wavelength range ZLR2 the luminescent material light 201 may have spectral power. In embodiments, the second light generating device 120 may be configured to generate second device light 121. Further, in embodiments in at least part of a second device light wavelength range DR2 the second device light 121 may have (non-zero) spectral power. Further, as indicated above, the second light generating device 120 may comprise a solid-state light source selected from the group of laser diodes, superluminescent diodes, and multi -junction diodes. As indicated above, the optics 500 may comprise redirection elements 510,520,530. In embodiments, a first redirection element 510 and a third 2024PF80214

[0305] 72 redirection element 530 may be configured in an optical path between the first light generating device 110 and the luminescent material element 2000. Further, in embodiments, the first redirection element 510 may be configured to direct at least part of the first device light 111 received by the first redirection element 510 to the luminescent material element 2000 via the third redirection element 530. Yet, in embodiments the third redirection element 530 may be (a) transmissive for first device light 111, received by the third redirection element 530, (b) transmissive for luminescent material light 201 having a wavelength in the first luminescence wavelength range XLR1, received by the third redirection element 530, (c) transmissive for luminescent material light 201 having a wavelength in the second luminescence wavelength range XLR2 comprising a first linear polarization, received by the third redirection element 530, and (d) reflective for luminescent material light 201 having a wavelength in the second luminescence wavelength range XLR2 and comprising a second linear polarization, different from the first linear polarization, received by the third redirection element 530. Yet, in embodiments the optics 500 may be configured such that at least part of the luminescent material light 201 having a wavelength in the second luminescence wavelength range XLR2 and comprising the second linear polarization may be directed back to the luminescent material element 2000. Further, in embodiments the first redirection element 510 may be configured to direct (a) luminescent material light 201 having a wavelength in the first luminescence wavelength range ZLR1, and (b) luminescent material light 201 having a wavelength in the second luminescence wavelength range ZLR2 and comprising the first linear polarization, received by the first redirection element 510, in an optical path to the light exit 1090, via a second redirection element 520. Furthermore, in embodiments the second redirection element 520 may be configured to direct (a) luminescent material light 201 having a wavelength in the first luminescence wavelength range ZLR1, (b) luminescent material light 201 having a wavelength in the second luminescence wavelength range ZLR2 and comprising the first linear polarization, and (c) second device light 121 comprising the second linear polarization, received by the second redirection element 520, into an optical path to the light exit 1090. As can be derived from the above, in embodiments the light generating system 1000 may be configured to generate system light 1001 comprising, one or more of (a) at least part of the luminescent material light 201 having a wavelength in the first luminescence wavelength range ZLR1, (b) at least part of the luminescent material light 201 having a wavelength in the second luminescence wavelength range ZLR2 and comprising the first linear polarization, and (c) at least part of the second device light 121 comprising the second linear polarization. 2024PF80214

[0306] 73

[0307] As indicated above, the (reflective) diffuser arrangement 1700 may thus be optional. Would it however be desirable to have the second device light 121 escape from the system 1000 (via the light exit 1090), then the (reflective) diffuser arrangement 1700 and / or a transmissive diffuser arrangement, etc., may be present (see also above).

[0308] Note that the diffuser arrangements 1700 in the embodiments of Figs. 2a-2c may thus be optional (with some minor change of the optical elements 500).

[0309] Note that in Fig. 2a and 2b, by way of example, embodiments are depicted wherein a third light generating device 130 may optionally be available. Here, by way of example the device light 131 is not diffused via a diffuser arrangement of the type of the diffuser arrangement 1700 as used for the second device light. Hence, actually these drawings show examples of how also second device light 121 could be added without using the diffuser arrangement 1700, as indicated above as example. On the other hand, however, a diffuser arrangement like the diffuser arrangement 1700 could also be used to diffuse the third device light 131.

[0310] Fig. 3 schematically depicts an embodiment of a luminaire 2 comprising the light generating system 1000 as described above. Reference 301 indicates a user interface which may be functionally coupled with the control system 300 comprised by or functionally coupled to the light generating system 1000. Fig. 3 also schematically depicts an embodiment of lamp 1 comprising the light generating system 1000. Reference 3 indicates a projector device or projector system, which may be used to project images, such as at a wall, which may also comprise the light generating system 1000. Hence, Fig. 3 schematically depicts embodiments of a lighting device 1200 selected from the group of a lamp 1, a luminaire 2, a projector device 3, a disinfection device, a photochemical reactor, and an optical wireless communication device, comprising the light generating system 1000 as described herein. In embodiments, such lighting device may be a lamp 1, a luminaire 2, a projector device 3, a disinfection device, or an optical wireless communication device. Lighting device light escaping from the lighting device 1200 is indicated with reference 1201. Lighting device light 1201 may essentially consist of system light 1001, and may in specific embodiments thus be system light 1001. Reference 1300 refers to a space, such as a room. Reference 1305 refers to a floor and reference 1310 to a ceiling; reference 1307 refers to a wall. In (other) embodiments, the lamp 1 may be a torch.

[0311] Fig. 3 also schematically depicts an embodiment of an outdoor light, or stage light, or stadium light. Fig. 3 also schematically depicts a vehicle, like an automobile, but this 2024PF80214

[0312] 74 may also be a truck, a motor cycle, etc. etc., with automotive lighting 4, e.g. headlights. These automotive lighting 4 may also comprise the lighting device 1200.

[0313] The term “plurality” refers to two or more. The terms “substantially” or “essentially” herein, and similar terms, will be understood by the person skilled in the art. The terms “substantially” or “essentially” may also include embodiments with “entirely”, “completely”, “all”, etc. Hence, in embodiments the adjective substantially or essentially may also be removed. Where applicable, the term “substantially” or the term “essentially” may also relate to 90% or higher, such as 95% or higher, especially 99% or higher, even more especially 99.5% or higher, including 100%. The term “comprise” also includes embodiments wherein the term “comprises” means “consists of’. The term “and / or” especially relates to one or more of the items mentioned before and after “and / or”. For instance, a phrase “item 1 and / or item 2” and similar phrases may relate to one or more of item 1 and item 2. The term "comprising" may in an embodiment refer to "consisting of but may in another embodiment also refer to "containing at least the defined species and optionally one or more other species". Use of the verb "to comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”. The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

[0314] Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

[0315] The devices, apparatus, or systems may herein amongst others be described during operation. As will be clear to the person skilled in the art, the invention is not limited to methods of operation, or devices, apparatus, or systems in operation.

[0316] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. 2024PF80214

[0317] 75

[0318] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

[0319] The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In a device claim, or an apparatus claim, or a system claim, enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. In yet a further aspect, the invention (thus) provides a software product, which, when running on a computer is capable of bringing about (one or more embodiments of) the method as described herein.

[0320] The invention also provides a control system that may control the device, apparatus, or system, or that may execute the herein described method or process. Yet further, the invention also provides a computer program product, when running on a computer which is functionally coupled to or comprised by the device, apparatus, or system, controls one or more controllable elements of such device, apparatus, or system.

[0321] The invention further applies to a device, apparatus, or system comprising one or more of the characterizing features described in the description and / or shown in the attached drawings. The invention further pertains to a method or process comprising one or more of the characterizing features described in the description and / or shown in the attached drawings.

[0322] The various aspects discussed in this patent can be combined in order to provide additional advantages. Further, the person skilled in the art will understand that embodiments can be combined, and that also more than two embodiments can be combined. Furthermore, some of the features can form the basis for one or more divisional applications.

Claims

1. 2024PF8021476CLAIMS:

1. A light generating system (1000) comprising a first light generating device(110), a second light generating device (120), a luminescent material element (2000), optics (500), and a light exit (1090), wherein: the first light generating device (110) is configured to generate first device light (111); wherein the first device light (111) has a first peak wavelength (kpl) selected from the wavelength range of 380-490 nm; wherein the first light generating device (110) comprises a solid-state light source selected from the group of laser diodes, superluminescent diodes, and multi -junction diodes; the luminescent material element (2000) comprises a luminescent material (200); wherein the luminescent material (200) is configured to convert at least part of the first device light (111) received by the luminescent material element (2000) into luminescent material light (201); wherein in at least part of a first luminescence wavelength range (ZLR1) and in at least part of a second luminescence wavelength range (ZLR2) the luminescent material light (201) has spectral power; the second light generating device (120) is configured to generate second device light (121); wherein in at least part of a second device light wavelength range (ZDR2) the second device light (121) has spectral power; wherein the second light generating device (120) comprises a solid-state light source selected from the group of laser diodes, superluminescent diodes, and multi -junction diodes; the optics (500) comprise redirection elements (510,520,530); a first redirection element (510) and a third redirection element (530) are configured in an optical path between the first light generating device (110) and the luminescent material element (2000); the first redirection element (510) is configured to direct at least part of the first device light (111) received by the first redirection element (510) to the luminescent material element (2000) via the third redirection element (530); the third redirection element (530) is (a) transmissive for first device light(111), received by the third redirection element (530), (b) transmissive for luminescent material light (201) having a wavelength in the first luminescence wavelength range (ZLR I ),2024PF8021477 received by the third redirection element (530), (c) transmissive for luminescent material light (201) having a wavelength in the second luminescence wavelength range (XLR2) comprising a first linear polarization, received by the third redirection element (530), and (d) reflective for luminescent material light (201) having a wavelength in the second luminescence wavelength range (XLR2) and comprising a second linear polarization, different from the first linear polarization, received by the third redirection element (530); the optics (500) are configured such that at least part of the luminescent material light (201) having a wavelength in the second luminescence wavelength range (XLR2) and comprising the second linear polarization is directed back to the luminescent material element (2000); the first redirection element (510) is configured to direct (a) luminescent material light (201) having a wavelength in the first luminescence wavelength range (XLR1), and (b) luminescent material light (201) having a wavelength in the second luminescence wavelength range (XLR2) and comprising the first linear polarization, received by the first redirection element (510), in an optical path to the light exit (1090), via a second redirection element (520); the second redirection element (520) is configured to direct (a) luminescent material light (201) having a wavelength in the first luminescence wavelength range (XLR1), (b) luminescent material light (201) having a wavelength in the second luminescence wavelength range (XLR2) and comprising the first linear polarization, and (c) second device light (121) comprising the second linear polarization, received by the second redirection element (520), into an optical path to the light exit (1090); and the light generating system (1000) is configured to generate system light (1001) comprising, one or more of (a) at least part of the luminescent material light (201) having a wavelength in the first luminescence wavelength range (XLR1), (b) at least part of the luminescent material light (201) having a wavelength in the second luminescence wavelength range (XLR2) and comprising the first linear polarization, and (c) at least part of the second device light (121) comprising the second linear polarization.

2. The light generating system (1000) according to claim 1, wherein the optics(500) further comprise a diffuser arrangement (1700); and wherein: the diffuser arrangement (1700) comprises a retarder element (550) and a polarization maintaining diffuser (710); wherein the retarder element (550) comprises a X / 4 plate;2024PF8021478 the second redirection element (520) and the retarder element (550) are configured in an optical path between the second light generating device (120) and the polarization maintaining diffuser (710); the light generating system (1000) is configured such that second device light (121) received by the second redirection element (520) comprises the first linear polarization; the second redirection element (520) is configured to direct second device light (121) comprising the first linear polarization, received by the second redirection element (520), in an optical path to the diffuser arrangement (1700); the diffuser arrangement (1700) is configured to convert second device light (121) comprising the first linear polarization, received by the diffuser arrangement (1700), into diffused second device light (121) comprising the second linear polarization; the second redirection element (520) is configured to direct (a) luminescent material light (201) having a wavelength in the first luminescence wavelength range (XLR1), (b) luminescent material light (201) having a wavelength in the second luminescence wavelength range (XLR2) and comprising the first linear polarization, and (c) diffused second device light (121) comprising the second linear polarization, received by the second redirection element (520), into an optical path to the light exit (1090); and the light generating system (1000) is configured to generate system light (1001) comprising, one or more of (a) at least part of the luminescent material light (201) having a wavelength in the first luminescence wavelength range (XLR1), (b) at least part of the luminescent material light (201) having a wavelength in the second luminescence wavelength range (XLR2) and comprising the first linear polarization, and (c) at least part of the diffused second device light (121) comprising the second linear polarization.

3. The light generating system (1000) according to any one of the preceding claims, wherein one or more of the following applies: the light generating system (1000) is configured such that at least part of the luminescent material light (201) having a wavelength in the second luminescence wavelength range (XLR2) and comprising the second linear polarization that is received by the luminescent material element (2000) after having been directed back thereto, is converted into further luminescent material light comprising a wavelength in a second luminescence wavelength range (ZLR2) and comprising the first linear polarization.2024PF80214794. The light generating system (1000) according to any one of the preceding claims, wherein in the first luminescence wavelength range (XLR1) the luminescent material light (201) has a first spectral power Pl, wherein in the second luminescence wavelength range (XLR2) the luminescent material light (201) has a second spectral power P2, wherein 0.05<P2 / Pl<0.5.

5. The light generating system (1000) according to any one of the preceding claims, wherein the second device light (121) has a second peak wavelength (Zp2) within the second luminescence wavelength range (ZLR2).

6. The light generating system (1000) according to any one of the preceding claims, wherein the luminescent material (200) comprises one or more of (a) a luminescent material of the type AsBsOn Ce, wherein A comprises one or more of Y, La, Gd, Tb and Lu, and wherein B comprises one or more of Al, Ga, In and Sc, and (b) a luminescent material selected from the types of a divalent europium comprising nitride luminescent material and a divalent europium comprising oxynitride luminescent material.

7. The light generating system (1000) according to any one of the preceding claims, wherein the second luminescence wavelength range (ZLR2) and the second device light wavelength range (ZDR2) are at least partly comprised in a wavelength range of 490- 640 nm.

8. The light generating system (1000) according to any one of the preceding claims 1-7, wherein the second device light (121) has a second peak wavelength (Zp2) in the green-yellow wavelength range.

9. The light generating system (1000) according to any one of the preceding claims 1-7, wherein the second light generating device (120) is configured to generate second device light (121) having a second peak wavelength (Zp2) in the 610-680 nm wavelength range.

10. The light generating system (1000) according to any one of the preceding claims 1-9, wherein first redirection element (510) comprises a multichroic based beam splitter; and wherein the second redirection element (520) comprises a polarizing beam2024PF8021480 splitter for the second device light (121), and wherein the third redirection element (530) comprises a reflective polarizer for light in the second luminescence wavelength range (XLR2).

11. The light generating system (1000) according to any one of the preceding claims 1-9, wherein the third redirection element (530) comprises a polarizing beam splitter for light in the second luminescence wavelength range (XLR2); wherein the optics (500) comprises a reflective element (540); and wherein: the light generating system (1000) is configured such that at least part of the luminescent material light (201) having a wavelength in the second luminescence wavelength range (XLR2) and comprising the second linear polarization propagates in an optical path from the luminescent material (200) to the reflective element (540) via the third redirection element (530), and wherein the reflective element (540) is configured to reflect luminescent material light (201) having a wavelength in the second luminescence wavelength range (XLR2) and comprising the second linear polarization, received by the reflective element (540), back to the luminescent material element (2000) via the third redirection element (530).

12. The light generating system (1000) according to any one of the preceding claims, further comprising a third light generating device (130) configured to generate third device light (131); wherein the third device light (131) has a third peak wavelength (Zp3) in the 380-490 nm wavelength range; and wherein the third light generating device (130) comprises a solid- state light source selected from the group of diode lasers, superluminescent diodes, and multi -junction diodes; the optics (500) are configured to direct the third device light (131) in an optical path to the light exit (1090); and in an operational mode of the light generating system (1000) the system light (1001) is white light comprising (a) at least part of the luminescent material light (201) having a wavelength in the first luminescence wavelength range (ZLR1), (b) at least part of the luminescent material light (201) having a wavelength in the second luminescence wavelength range (ZLR2) and comprising the first linear polarization, (c) at least part of the diffused second device light (121) comprising the second linear polarization, and (d) at least part of the third device light (131); wherein the system light (1001) in this operational mode2024PF8021481 has a correlated color temperature selected from the range of 1500-12000 K and a color rendering index of at least 80.

13. The light generating system (1000) according to any one of the preceding claims 1-11, comprising an arrangement of the second light generating device (120) and a third light generating device (130); wherein: the third light generating device (130) is configured to generate third device light (131); wherein the third device light (131) has a third peak wavelength (Xp3 ) in the 380- 490 nm wavelength range; and wherein the third light generating device (130) comprises a solid-state light source selected from the group of diode lasers, superluminescent diodes, and multi -junction diodes; the arrangement of the second light generating device (120) and a third light generating device (130) is configured upstream of the second redirection element (520); the light generating system (1000) is configured such that the second device light (121) and the third device light (131) received by second redirection element (520) comprise device light comprising the same linear polarization; and in an operational mode of the light generating system (1000) the system light (1001) is white light comprising (a) at least part of the luminescent material light (201) having a wavelength in the first luminescence wavelength range (ZLR1), (b) at least part of the luminescent material light (201) having a wavelength in the second luminescence wavelength range (ZLR2) and comprising the first linear polarization, (c) at least part of the (diffused) second device light (121) comprising the second linear polarization, and (d) at least part of the third device light (131); wherein the system light (1001) in this operational mode has a correlated color temperature selected from the range of 1500-12000 K and a color rendering index of at least 80.

14. The light generating (1000) according to any one of the preceding claims, further comprising a control system (300), wherein the control system (300) is configured to control a spectral power distribution of the system light (1001) by individually controlling the first light generating device (110), the second light generating device (120), and the optional third light generating device (130) according to any one of claims 12-13.2024PF802148215. A lighting device (1200) selected from the group of a lamp (1), a luminaire(2), a projector device (3), and a lighting fixture, comprising the light generating system (1000) according to any one of the preceding claims.

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