Eye-safe laser-based lighting with improved performance

Abstract

The invention provides a light generating system (1000) comprising a first light generating device (110), a second light generating device (120), optics (500), a luminescent material (200), and a light exit (1090), wherein: - the first light generating device (100) is configured to generate first device light (111); - the optics (500) comprise one or more diffusers (600), a first redirection element (510), and a retarder element (550); - the one or more diffusers (600) are configured in an optical path between the first light generating device (110) and the light exit (1090) and configured to diffuse the first device light (111); wherein the one or more diffusers (600) at least comprises a segmented specular reflecting metallic reflector (610); - the optics (500) comprise a first diffuser arrangement (601); wherein the first diffuser arrangement (601) comprises the retarder element (550) and the specular reflecting metallic reflector (610); - the second light generating device (120) is configured to generate second device light (121); - the luminescent material (200) is configured to convert at least part of the second device light (121), into luminescent material light (201); and - the light generating system (1000) is configured to generate system light (1001) comprising one or more of (a) at least part of the first device light (111) and (b) the luminescent material light (201).

Description

[0001] 2024PF80076

[0002] 1

[0003] EYE-SAFE LASER-BASED LIGHTING WITH IMPROVED PERFORMANCE

[0004] FIELD OF THE INVENTION

[0005] The invention relates to a light generating system. The invention further relates to a lighting device comprising the light generating system.

[0006] BACKGROUND OF THE INVENTION

[0007] Lighting fixtures with built-in eye-safety are known in the art. US2019323803A1, for instance, describes a laser system comprising: an active laser with at least one beam guide and an effective range about an object / target when the active laser is in use; a protection device with at least one additional laser that operates in a visible spectral range, wherein the at least one additional laser is switched on if at least one person has been detected in the effective range of the active laser before the active laser is used.

[0008] SUMMARY OF THE INVENTION

[0009] Laser-phosphor systems may allow generation of high brightness light and may therefore be used in projection systems, including displays such as cinema projectors and projectors for home, school, and office applications, car front lighting, search lighting, stage lighting, architectural lighting, and special lighting applications. However, the maximum brightness may be limited by the components used, the engine volume may be large due to the many components, and the system cost may be high due to the many dedicated components. Further, prior art systems may have relatively high risks for eyesafety should one or more optical components break or malfunction. Therefore, it may be desired to improve the safety, compactness and / or performance / cost ratio of laser-phosphor technology. Hence, it is an aspect of the invention to provide an alternative light generating system, 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.

[0010] According to a first aspect, the invention provides a light generating system (“system”) comprising a first light generating device, optics, and a light exit, as well as optionally a luminescent material, and optionally a second light generating device. 2024PF80076

[0011] 2

[0012] Especially, the first light generating device may be configured to generate first device light. In embodiments, the first light generating device may comprise one or more of a laser diode, a superluminescent diode, and a multi -junction diode. Further, in embodiments the first device light may have spectral power at one or more wavelengths selected from the range of 380-780 nm. In specific embodiments, the optics may comprise one or more diffusers, a first redirection element, and a retarder element. Especially, in embodiments the one or more diffusers may be configured in an optical path between the first light generating device and the light exit and configured to diffuse the first device light. Further, in embodiments the one or more diffusers may at least comprise a segmented specular reflecting metallic reflector. In embodiments, the segmented specular reflecting metallic reflector may be configured in a light receiving relationship with the first light generating device. Especially, in embodiments the segmented specular reflecting metallic reflector may have a first full width half maximum diffusion angle (91) for coherent light under a first predetermined angle of incidence (ail) (on the segmented specular reflecting metallic reflector). In specific embodiments, the first full width half maximum diffusion angle (91) may be selected from the range of 1-49°, especially selected from the range of 1-29° (though other values may also be possible). Further, in embodiments the optics may comprise a first diffuser arrangement. In specific embodiments, the first diffuser arrangement may comprise the retarder element and the specular reflecting metallic reflector. Especially, in embodiments the retarder element may comprise a X / 4 plate. Yet, in embodiments the retarder element may be configured in an optical path between the first redirection element and the specular reflecting metallic reflector. Especially, in embodiments the first diffuser arrangement may be configured to diffuse the first device light and change the first linear polarization into a second linear polarization, different from the first linear polarization. Further, in embodiments the first redirection element may be configured in an optical path between the first light generating device and the first diffuser arrangement. Especially, in embodiments the light generating system may be configured such that the first device light reaching the first redirection element comprises a first linear polarization. In embodiments, the first redirection element may be configured (a) to direct the first device light comprising the first linear polarization, reaching the first redirection element, in an optical path to the first diffuser arrangement, and (b) to direct the first device light comprising the second linear polarization, emanating from the first diffuser arrangement and reaching the first redirection element, in an optical path to the light exit. Hence, in embodiments the light generating system may be configured to generate system light comprising at least part of the first device light (diffused by the one or 2024PF80076

[0013] 3 more diffusers (comprising the segmented specular reflecting metallic reflector and)) directed via the first redirection element in the optical path to the light exit. Further, in embodiments the light generating system may comprise a second light generating device. Especially, the second light generating device may be configured to generate second device light. Further, in embodiments the second light generating device may comprise one or more of a laser diode, a superluminescent diode, and a multi -junction diode. Especially, in embodiments the second device light may have spectral power at one or more wavelengths selected from the range of 380-490 nm, though other wavelength ranges may also be possible. Yet, further, in embodiments the light generating system may comprise a luminescent material. In specific embodiments, the luminescent material may be configured to convert at least part of the second device light, received by the luminescent material, into luminescent material light. Hence, in embodiments the light generating system may be configured to generate system light comprising one or more of (a) at least part of the first device light (diffused by the one or more diffusers (comprising the segmented specular reflecting metallic reflector and) directed via the first redirection element in the optical path to the light exit and (b) the luminescent material light. Therefore, in specific embodiments the invention provides a light generating system comprising a first light generating device, a second light generating device, optics, a luminescent material, and a light exit, wherein: (A) the first light generating device is configured to generate first device light; wherein the first light generating device comprises one or more of a laser diode, a superluminescent diode, and a multi -junction diode; wherein the first device light has spectral power at one or more wavelengths selected from the range of 380-780 nm; (B) the optics comprise one or more diffusers, a first redirection element, and a retarder element; (C) the one or more diffusers are configured in an optical path between the first light generating device and the light exit and configured to diffuse the first device light; wherein the one or more diffusers at least comprises a segmented specular reflecting metallic reflector, configured in a light receiving relationship with the first light generating device; wherein the segmented specular reflecting metallic reflector has a first full width half maximum diffusion angle (01) for coherent light under a first predetermined angle of incidence (ail) (on the segmented specular reflecting metallic reflector), wherein the first full width half maximum diffusion angle (91) is selected from the range of 1-20°; (D) the optics comprise a first diffuser arrangement; wherein the first diffuser arrangement comprises the retarder element and the specular reflecting metallic reflector; wherein the retarder element comprises a X / 4 plate, wherein the retarder element is configured in an optical path between the first redirection element and the specular reflecting metallic reflector; wherein 2024PF80076

[0014] 4 the first diffuser arrangement is configured to diffuse the first device light and change the first linear polarization into a second linear polarization, different from the first linear polarization; (E) the first redirection element is configured in an optical path between the first light generating device and the first diffuser arrangement; wherein the light generating system is configured such that the first device light reaching the first redirection element comprises a first linear polarization; wherein the first redirection element is configured (a) to direct the first device light comprising the first linear polarization, reaching the first redirection element, in an optical path to the first diffuser arrangement, and (b) to direct the first device light comprising the second linear polarization, emanating from the first diffuser arrangement and reaching the first redirection element, in an optical path to the light exit; (F) the second light generating device is configured to generate second device light; wherein the second light generating device comprises one or more of a laser diode, a superluminescent diode, and a multi -junction diode, wherein the second device light has spectral power at one or more wavelengths selected from the range of 380-490 nm; (G) the luminescent material is configured to convert at least part of the second device light, received by the luminescent material, into luminescent material light; and (H) the light generating system is configured to generate system light comprising one or more of (a) at least part of the first device light (diffused by the one or more diffusers (comprising the segmented specular reflecting metallic reflector) and) directed via the first redirection element in the optical path to the light exit and (b) the luminescent material light.

[0015] With such light generating system high intensity (laser) light may be provided, that may still be relatively safe. Further, when using two (or more) diffusers, safety can even be higher and / or efficiency may be higher. Further, with the system it may be possible to provide white light, optionally having controllable spectral properties. Further, should a luminescent material be applied, the beam sizes and / or full width half maximum angles of the luminescent material light and the diffused first device light may better be matched. Hence, amongst others the invention may provide eye-safe laser-based lighting with improved performance, for instance, for stage lighting.

[0016] As indicated above, the invention may provide a light generating system comprising a first light generating device, optics, and a light exit. In further embodiments, the light generating system may (optionally) comprise a luminescent material. Further, the light generating system may (optionally) comprise a second light generating device, especially in embodiments wherein the light generating system also comprises the luminescent material. Further embodiments of the system are described below. 2024PF80076

[0017] 5

[0018] The system comprises a first light generating device and optionally a second light generating device. The term “first light generating device” may also refer to a plurality of (essentially identical) first light generating devices, such as from the same bin. The term “second light generating device” may also refer to a plurality of (essentially identical) second light generating devices, such as from the same bin. Especially, each light generating device may comprise a (solid state) light source, configured to generate light source light. Hence, especially the light of the light generating device may in embodiments comprise, or essentially consist, of the light source light of the solid state) light source. Here below, some embodiments of light generating devices and light sources are described in general.

[0019] The term “light source” may in principle relate to any light source known in the art. It may be a conventional (tungsten) light bulb, a low pressure mercury lamp, a high pressure mercury lamp, a fluorescent lamp, an LED (light emitting diode). In a specific embodiment, the light source comprises a solid state 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. Further, the term “light source” may in embodiments also refer to a so-called chip-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.

[0020] 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 2024PF80076

[0021] 6

[0022] 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.

[0023] The light source may have a light escape surface. Referring to conventional light sources such as light bulbs or fluorescent lamps, it may be an outer surface of a glass or a quartz envelope. 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.

[0024] 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.

[0025] 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).

[0026] The term LED may also refer to a plurality of LEDs.

[0027] 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).

[0028] 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, 2024PF80076

[0029] 7 which may not comprise a luminescent material (“phosphor”) may be indicated as direct color LEDs.

[0030] In other embodiments, however, the light source may be configured to provide primary radiation and part of the primary radiation is converted into secondary radiation. Secondary radiation may be based on conversion by a luminescent material. The secondary radiation may therefore also be indicated as luminescent material radiation. The luminescent material may in embodiments be comprised by the light source, such as an LED with a luminescent material layer or dome comprising luminescent material. Such LEDs may be indicated as phosphor converted LEDs or PC LEDs (phosphor converted LEDs). In other embodiments, the luminescent material may be configured at some distance (“remote”) from the light source, such as an LED with a luminescent material layer not in physical contact with a die of the LED. Hence, in specific embodiments the light source may be a light source that during operation emits at least light at wavelength selected from the range of 380-470 nm. However, other wavelengths may also be possible. This light may partially be converted by the luminescent material.

[0031] In embodiments, the light generating device may comprise a luminescent material. In embodiments, the light generating device may comprise a PC LED. In other embodiments, the light generating device may comprise a direct LED (i.e. no phosphor). In embodiments, the light generating device may comprise a laser device, like a laser diode. In embodiments, the light generating device may comprise a superluminescent diode. Hence, in specific embodiments, the light source may be selected from the group of laser diodes and superluminescent diodes. In other embodiments, the light source may comprise an LED.

[0032] 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, having band widths as known for lasers.

[0033] 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 2024PF80076

[0034] 8 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).

[0035] 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.

[0036] 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 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.

[0037] 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.

[0038] 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.

[0039] 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 laser diode, or a superluminescent diode.

[0040] 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. The semiconductors for lasers mentioned herein may also be used as (semiconductor) LEDs. 2024PF80076

[0041] 9

[0042] The term “semiconductor light source” may comprise a semiconductor configured to generate light, herein also indicated a “solid state light source”. The term “solid state light source” may refer to a LED, a laser diode, a super luminescent diode, multijunction diode, VCSELs (vertical-cavity surface-emitting laser), etc. The term semiconductor light source and light generating device may herein interchangeably be used; the semiconductor light source or light generating device may comprise one or more semiconductors (configured to generate light) and optionally a luminescent material. Here below, some aspects in relation to (solid state) light sources and light generating devices are described.

[0043] 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. In embodiments, laser banks may be applied. Laser banks may also be used to boast the input power. Therefore, in embodiments the system may comprise a plurality of light generating devices configured in a laser bank. A laser bank may comprise a light emitting arrangement comprising an (2D) array of a plurality of laser diodes arranged on a thermally conductive carrier and a (lens array having a) plurality of collimator lenses corresponding to the laser diodes such that each laser diode of the plurality of laser diodes comprises a collimator lens for collimating laser light emitted by the laser diode. The arrangement may comprise a package architecture or a canned architecture. In case of the package architecture a laser diode chip array is arranged on the thermally conductive carrier. A plurality of electrodes may be present for electrically connecting the plurality of laser diodes.

[0044] In relation to the first light generating device, it is noted that especially the first light generating device may be configured to generate first device light. In specific embodiments, the first light generating device may comprise one or more of a laser diode, a superluminescent diode, and a multi -junction diode. Especially, the first light generating device may comprise a laser diode. In specific embodiments, the first light generating device may comprise a first laser bank comprising a plurality of first lasers (i.e. especially first laser diodes). The spectral power distribution of the first device light may be selected from essentially any possible option, though in general with at least some spectral power, if not all, in the visible wavelength range. Hence, in embodiments the first device light may have spectral power at one or more wavelengths selected from the range of 380-780 nm. More especially, the first device light may have a peak wavelength in the wavelength range of 380- 780 nm. When white system light may be desirable in one or more operational modes of the 2024PF80076

[0045] 10 light generating system, the choice of the spectral power distribution of the first device light may. Herein, in specific embodiments the first device light may have a peak wavelength in the wavelength range of 380-490 nm, more especially a peak wavelength in the wavelength range of 430-490 nm, such as a peak wavelength in the wavelength range of 440-490 nm.

[0046] Further, the light generating system may comprise optics. 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 or mirrors, reflectors, collimators, lenses, prisms, diffusers, phase plates, polarizers, diffractive elements, gratings, dichroics, 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”).

[0047] Herein, in embodiments the optics may comprise one or more diffusers. Especially, in embodiments the one or more diffusers may be configured to diffuse the first device light, received by the one or more diffusers, upstream of the light exit. In this way, non-diffused first device light may essentially not escape from the light generating system, and first device light may essentially only escape from the light generating system as diffused first device light.

[0048] 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 the especially the light source), 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”.

[0049] In embodiments, the one or more diffusers may at least comprise a segmented specular reflecting metallic reflector. As known to a person skilled in the art, a metallic specular reflector may essentially not diffuse. However, a plurality of specular reflectors, or a plurality of differently orientated specular reflector parts, may diffuse light. Hence, in this way a segmented specular reflecting metallic reflector may be used to diffuse first device light. Segments may e.g. be provided by a specular reflecting metallic reflector comprising a plurality of (small) indentations, and / or a plurality of (small) protrusions. A plurality of the segments may essentially be planar and / or (another) plurality of the segments may be curved (in at least one dimension). In embodiments, the segments may have one or more sizes like 2024PF80076

[0050] 11 length, width, and / or height, selected from the range of about 0.5-200 gm, though other dimensions may also be possible. Especially, the segments are selected such that a substantial part of light impinging under a predetermined angle of incidence, like 0°, i.e. perpendicular to a cross-sectional plane of the segmented specular reflecting metallic reflector is reflected with angles of reflection different from the predetermined angle of incidence. For instance, at least 60% or at least 80% of the spectral power of the incident light, may be diffused (i.e. diffusively reflected). Hence, in embodiments the segments define maxima and minima, wherein distances between adjacent maxima may be selected from the range of 0.5-200 gm, such as selected from the range of 1 - 100 gm, and the height difference between maxima and adjacent minima may be selected from the range of 0.1-100 gm, such as selected from the range of 0.5 - 50 gm. In embodiments, the distances between adjacent maxima may be selected from the range of 2-80 gm. Alternatively or additionally, in embodiments the height difference between maxima and adjacent minima may be selected from the range of 1-40 gm.

[0051] In this way, fully coherent light may be diffused, and non-coherent may be further diffused. The diffusion may be defined by a diffusion angle, assuming fully coherent light. In embodiments, the term “diffusion angle” may refer to the (relatively smooth) broadening of an incident beam of radiation that may be characterized by the full width at half maximum of the diffused radiant angular intensity distribution for an incident (nondiffused) pencil beam (i.e., an FWHM of the diffused beam compared to the incident beam of radiation with a negligible angular extent (FWHM)).

[0052] The spatial light distribution (of e.g. a diffused beam of light (be it via reflective diffused, as described amongst others here, of via transmissive diffusion, as described elsewhere herein) may be measured optically e.g. using a goniophotometer.

[0053] Hence, in embodiments the segmented specular reflecting metallic reflector may have a first full width half maximum diffusion angle (91) for coherent light under a first predetermined angle of incidence (ail) (on the segmented specular reflecting metallic reflector, wherein the first full width half maximum diffusion angle (91) is selected from the range of 9.5-49°, more especially 1-29°.

[0054] The one or more diffusers, especially the segmented specular reflecting metallic reflector may diffuse the first device light. In this way, the beam may be broadened. This may provide (additional) safety. Hence, in specific embodiments the one or more diffusers may be configured to increase an etendue of the first device light.

[0055] The first device light escaping from the first light generating device may not be fully coherent, but may already have a full width half maximum (FWHM) beam width of 2024PF80076

[0056] 12 in the order of about 1-40°, such as in embodiments in the order of about 20°, which may e.g. apply to (semiconductor) laser diodes. However, using a collimator element, downstream of the first light generating device, may reduce the beam width. Downstream thereof, however, the first device light may be diffused with the segmented specular reflecting metallic reflector. This may lead to the above indicated broadening. For instance, directly downstream of the segmented specular reflecting metallic reflector, the reflected (and diffused) first device light may e.g. have a full width half maximum diffusion angle (0S 11 ) selected from the range of 1-60°, more especially selected from the range of 1-40°. Herein the term FWHM may thus especially refer to a FWHM beam divergence.

[0057] Hence, in embodiments a laser diode as first light generating device may in embodiments provide (laser diode) first device light which may have a (narrow) collimation e.g. 20°. In embodiments, (directly) downstream thereof optics, e.g. a lens / lens array, may be arranged, to collimate this laser light. Collimated laser light may then be directed onto the segmented specular reflecting metallic reflector, optionally using further optical elements, either as parallel beam as focusing the beam on it. Then this beam is diffused. As indicated elsewhere herein, the diffused light may be collimated again by a optics, such as a lens, to obtain a substantially parallel beam.

[0058] However, the beam angle of the first device light may be reduced further in the light generating system by using one or more (further) collimator elements (see further also below). For instance, in embodiments the optics comprise one or more collimating optical elements, wherein the first light generating device and the optics may be selected and configured such that first device light escaping from the light generating system via the light exit may have upon escape from the light exit a system light full width half maximum diffusion angle (0SF) selected from the range of 0.1-3°. Especially, in embodiments first device light escaping from the light generating system via the light exit may, in an operational mode of the light generating system 1000, have upon escape from the light exit a system light full width half maximum diffusion angle (0SF) selected from the range of 0.1- 3°, such as selected from the range of 0.1-12 (and in specific embodiments even 0.1-1°).

[0059] The diffusion properties of the segmented specular reflecting metallic reflector may be such, that the (diffused) device light may already be relatively safe. In embodiments, the first light generating device and the optics may be selected and configured such that first device light emanating from the specular reflecting metallic reflector has a radiance of at maximum 90 W / (cm2.sr). Note that this value may be directly downstream of the specular reflecting metallic reflector. In further specific embodiments, the first device light emanating 2024PF80076

[0060] 13 from the light generating system (via the light exit) may (thus) have a radiance of at maximum 90 W / (cm2.sr).

[0061] As indicated above, the segmented specular reflecting metallic reflector has a first full width half maximum diffusion angle (01) for coherent light under a first predetermined angle of incidence (ail) (on the segmented specular reflecting metallic reflector). As the segmented specular reflecting metallic reflector may have a non-planar surface, due to the segmented character, the first predetermined angle of incidence (ail) may be defined relative to a cross-sectional plane of the segmented specular reflecting metallic reflector. This cross-sectional plane may be planar (in one or two directions, especially two directions (though this is not necessarily the case)), and may in embodiments be parallel to a length and to a width of the segmented specular reflecting metallic reflector. For instance, the segmented specular reflecting metallic reflector may comprise a plate-like support on which features have been provided defining the segments.

[0062] The angle of incidence is in general defined relative to a normal to a surface (of incidence). Hence, herein a normal to the cross-sectional plane may be applied to relate the first predetermined angle of incidence (ail). Would an optical axis of the (coherent) light be perpendicular to the cross-sectional plane, then the first predetermined angle of incidence (ail) is 0°. Note that the segmented specular reflecting metallic reflector may not necessarily be designed for perpendicular irradiation. Therefore, the first predetermined angle of incidence (ail) may be non-zero. However, in embodiments the first predetermined angle of incidence (ail) may be zero. This may also imply that (a beam of) the first device light received by the segmented specular reflecting metallic reflector may have the first predetermined angle of incidence (ail) (which may in embodiments thus be 0°). In embodiments, the first predetermined angle of incidence (ail) may be in a range from 0° to 2°. In such embodiments, the first diffuser arrangement may be a colinear arrangement or may be colinearly configured. In embodiments of a colinear diffuser arrangement, device light, which may (or may not) substantially not be diffused, propagating in an optical path from the light generating device that generates this device light 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. Hence, an optical axis of incoming (non-diffused) device light and an optical axis of diffused device light, may be parallel (and colinear), though the propagation directions may be opposite. 2024PF80076

[0063] 14

[0064] A colinear diffuser arrangement herein may in embodiments be applied as a polarization maintaining diffuser.

[0065] Especially, the term “optical axis” may be defined as an imaginary line that defines the path along which light propagates through a system starting from the light generating element, here especially the light source. Especially, the optical axis may coincide with the direction of the light with the highest radiant flux.

[0066] Especially, herein the specular reflecting metallic reflector may be comprised by a first diffuser arrangement. The first diffuser arrangement in combination with a (polarization based) first redirection element may allow directing device light comprising a first linear polarization to the specular reflecting metallic reflector and directing diffused first device light having a second linear polarization, different from the first linear polarization in an optical path to the light exit.

[0067] Hence, in embodiments the optics comprise a first redirection element and a first diffuser arrangement. Further, in embodiments the first redirection element may be configured in an optical path between the first light generating device and the first diffuser arrangement. Especially, in embodiments the light generating system may be configured such that the first device light reaching the first redirection element comprises the first linear polarization. Hence, the first device light may comprise linear polarized light and / or a polarizer may be configured downstream of the first light generating device and upstream of the first redirection element such that the first device light reaching the first redirection element may comprise linear polarized light. Especially, in embodiments the first diffuser arrangement may comprise a retarder element and (thus) the specular reflecting metallic reflector. Especially, in embodiments the retarder element may comprise a X / 4 plate. Further, in embodiments the retarder element may be configured in an optical path between the first redirection element and the specular reflecting metallic reflector. Yet, in embodiments the first diffuser arrangement may be configured to convert first device light comprising the first linear polarization, received by the diffuser arrangement, into first device light that may at least once have been diffused comprising a second linear polarization, different from the first linear polarization. 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 2024PF80076

[0068] 15 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 (i.e. 90° rotated)). Yet, in embodiments the first redirection element may be configured (a) to direct the first device light comprises a first linear polarization, reaching the first redirection element, in an optical path to the first diffuser arrangement, and (b) ) to direct the first device light that may at least once have been diffused comprising the second linear polarization, reaching the first redirection element, in an optical path to the light exit.

[0069] The phrase “first device light that may at least once have been diffused”, and similar phrases, may especially refer to first device light that has at least been diffused by the segmented specular reflecting metallic reflector.

[0070] Especially, in embodiments the first redirection element may comprise a polarizing beam splitter. A polarizing beam splitter may be considered an example of (polarization based) redirection optics or (polarization based) redirecting 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 combiner two beams of light having different linear polarizations may be multiplexed (i.e. combined). 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, 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, than for a second polarization. Especially, in embodiments, 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 2024PF80076

[0071] 16 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).

[0072] As indicated above, in embodiments the light generating system may comprise a luminescent material. In embodiments, the luminescent material may be irradiated for the generation of luminescent material light with a part of the undiffused first device light, for instance when part of the first device light is branched off and directed to the luminescent material, especially before it reaches the first redirection element (though other embodiments may also be possible). Alternatively or additionally, the luminescent material may be irradiated for the generation of luminescent material light with part of the diffused first device light, for instance when part of the diffused device light is branched off and directed to the luminescent material. Yet alternatively or additionally, a second light generating device may be applied to irradiate the luminescent material for the generation of luminescent material light. Especially, herein in embodiments (a) essentially all first device light may be used to be directed to the specular reflecting metallic reflector, but without branching off to the luminescent material (when comprised by the light generating system), (b) essentially all diffused first device light generated may be directed in an optical pat the light exit, optionally via one or more further diffuser, but without branching off to the luminescent material (when comprised by the light generating system), and (c) a second light generating device may be applied to irradiate the luminescent material. Using another light generating device (other than the first light generating device) to generate luminescent material light may allow a better control of the system light, as it is in embodiments possible to control the system light by controlling the first light generating device and the second light generating device (individually).

[0073] Hence, in embodiments the light generating system may comprise a second light generating device, wherein the second light generating device may be configured to generate second device light. Especially, in embodiments the second light generating device comprises one or more of a laser diode, a superluminescent diode, and a multi -junction diode. 2024PF80076

[0074] 17

[0075] Especially, the second light generating device may comprise a laser diode. In specific embodiments, the second light generating device may comprise a second laser bank comprising a plurality of second lasers (i.e. especially second laser diodes). The spectral power distribution of the second device light may be selected from essentially any possible option, though in general with at least some spectral power, if not all, in the visible wavelength range. Hence, in embodiments the second device light may have spectral power at one or more wavelengths selected from the range of 380-780 nm. More especially, the second device light may have a peak wavelength in the wavelength range of 380-780 nm. However, the second device light may especially be selected such that it is at least partially absorbed by the luminescent material, and converted into luminescent material light. Hence, in embodiments the second device light has spectral power at one or more wavelengths selected from the range of 380-490 nm, though other wavelengths are herein not excluded. Especially, in specific embodiments the second device light may have a peak wavelength selected from the wavelength range of 300-490 nm, such as selected from the wavelength range of 380-490 nm, more especially a peak wavelength in the wavelength range of 430-490 nm, such as a peak wavelength in the wavelength range of 440-490 nm.

[0076] Further, as indicated above, in embodiments the light generating system may comprise a luminescent material. In specific embodiments, the luminescent material may be configured to convert at least part of the second device light, received by the luminescent material, into luminescent material light. The luminescent material light may have spectral power at one or more wavelengths selected from the range of 380-780 nm. In embodiments, the luminescent material light may comprise one or more of green light, yellow light, orange light, and red light.

[0077] Note that the term “luminescent material” may refer to a single luminescent material, or to a combination of two or more different luminescent material. The term “luminescent material” especially refers to a material that can convert first radiation, 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” or “luminescent converter material” may be applied. 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 down-conversion. 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. Here below, some general 2024PF80076

[0078] 18 aspect of luminescent materials are described, which may in principle apply to each of the luminescent materials described herein, of course taking into account the possible conditions the luminescent material are subjected to herein.

[0079] 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).

[0080] 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. The term “luminescent material” may also refer to a plurality of different luminescent materials. Examples of possible luminescent materials are indicated below. Hence, the term “luminescent material” may in specific embodiments also refer to a luminescent material composition. Instead of the term “luminescent material” also the term “phosphor” may be applied. These terms are known to the person skilled in the art.

[0081] 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.

[0082] In specific embodiments the luminescent material comprises a 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 2024PF80076

[0083] 19

[0084] 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. Such garnets may be doped with cerium (Ce), with praseodymium (Pr) or a combination of cerium and praseodymium; especially however with Ce. Especially, B may comprise aluminum (Al); however, in addition to aluminum, B may also partly comprise gallium (Ga) and / or scandium (Sc) and / or indium (In), especially up to about 20% of B, more especially up to about 10 % of B (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.

[0085] In specific embodiments, A may especially comprise at least Y, and B may especially comprise at least Al.

[0086] In embodiments, the luminescent material may alternatively or additionally comprise one or more of MS:Eu2+and / or LSisN^Eu2and / or MAlSiHrEu2and / 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 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 2024PF80076

[0087] 20 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 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). 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.

[0088] 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.

[0089] 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). 2024PF80076

[0090] 21

[0091] 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).

[0092] 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).

[0093] In embodiments, the luminescent material may comprise a luminescent material of the type Mi-xLi3-2yAli+2y-zSizO4-4y-zN4y+z:Eux. Herein, M may comprise one or more of magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba), such as especially one or more of Ca, Sr, and Ba. Hence, Mi-xLi3-2yAli+2y-zSizO4-4y-zN4y+z:Euxmay especially refer to (Mg,Ca,Sr,Ba)i-xLi3-2yAli+2y-zSizO4-4y-zN4y+z:Eux. Such a luminescent material may be indicated as an SLA-type phosphor, or SLA phosphor. Luminescent materials of the type Mi-xLi3-2yAli+2y-zSizO4-4y-zN4y+z:Eux may be described in US2021171827A1, which is hereby herein incorporated by reference. In Mi-xLi3-2yAli+2y-zSizO4-4y-zN4y+z:Eux, x may be selected from the range of 0 < x < 0.1, such as from the range of 0.0005 < x < 0.08, especially from the range of 0.001 < x < 0.05. Hence, europium (Eu) may not replace more than 10% of the cation M, and may substantially or only be in the divalent state (Eu2+), as is known to the person skilled in the art. Further, in Mi-xLi3-2yAli+2y-zSizO4-4y-zN4y+z:Eux, y may be selected from the range of 0 < y < 1, such as from the range of 0 < y < 0.75, especially from the range of 0 < y < 0.6. In specific embodiments, y = 0. In Mi-xLi3-2yAli+2y-zSizO4-4y-zN4y+z:Eux, z may be selected from the range of 0 < z < 0.1, such as from the range of 0 < z < 0.07, especially from the range of 0 < z < 0.05. Hence, in embodiments, in an SLA phosphor, SiN may replace A1O to a maximum of 10 mole%. In embodiments, an SLA phosphor may crystallize in a UCr4C4 type crystal structure. Hence, the luminescent material may comprise a luminescent material of the type Mi-xLi3-2yAli+2y-zSizO4-4y-zN4y+z:Eux, wherein M comprises one or more of Ca, Sr, and Ba, wherein 0 < x < 0.04, wherein 0 < y < 1, wherein 0 < z < 0.05, and wherein y + z < 1. 2024PF80076

[0094] 22

[0095] Further, the luminescent material may comprise a SiAlON phosphor, such as selected from the group comprising (a) S112— m— n Alm+nOnNi6-n:Eu2+(a-SiA10N), (b) Si6-nAlnOnN8-n:Eu2+, wherein 0 < n < 4.2 (P-SiAlON), and (c) Si2-nAlnOi+nN2-n:Eu2+, wherein 0 < n < 0.2 (O-SiAlON).

[0096] 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.

[0097] The term “luminescent material” herein especially relates to inorganic luminescent materials.

[0098] Hence, when M (or A) in chemical formulas refer to n different elements, this may imply that the relevant formula may comprise for the M (or A) position in the formula essentially any permutation of the n different elements. For instance, when M=Ba,Sr,Ca or when M comprises one or more of Ba, Sr, Ca or when M refers to Ba,Sr,Ca, i.e. n=3, this may imply that in the formula Ba, Sr, Ca, (BaxSry), (BaxCay), (CaxSry), or (BaxSryCaz), may be available, wherein in general x+y+z=l.

[0099] In embodiments, the luminescent material may comprise a luminescent material of the type M’xM2-2XAXe doped with tetravalent manganese, wherein M’ comprises an alkaline earth cation, M comprises an alkaline cation, and x is in the range of 0-1, wherein A comprises a tetravalent cation, for instance comprising one or more of silicon and titanium, wherein X comprises a monovalent anion, at least comprising fluorine. A luminescent material of the type M’xM2-2XAXe doped with tetravalent manganese is amongst others described in WO2013121355A1, which is herein incorporated by reference. Passages from WO2013121355A1 are also copied herein. Herein, M’xM2-2XAXe doped with tetravalent manganese, may further also shortly be indicated as “phosphor”, i.e. the phrase " phosphor comprising M’xM2-2XAXe doped with tetravalent manganese" may in an embodiment also be read as M’xM2-2XAXe doped with tetraval ent manganese phosphor, or (tetraval ent) Mn-doped M’xM2-2XAXe phosphor, or shortly "phosphor".

[0100] Relevant alkaline cations (M) are sodium (Na), potassium (K) and rubidium (Rb). Optionally, also lithium and / or cesium may be applied. In a preferred embodiment, M comprises at least potassium. In yet another embodiment, M comprises at least rubidium. The phrase “wherein M comprises at least potassium” indicates for instance that of all M cations in a mole M’xM2-2XAXe , a fraction comprises K+and an optionally remaining fraction comprises one or more other monovalent (alkaline) cations (see also below). In another preferred embodiment, M comprises at least potassium and rubidium. Optionally, the M’XM2- 2XAXe luminescent material has the hexagonal phase. In yet another embodiment, the M’XM2- 2024PF80076

[0101] 23

[0102] 2XAXe luminescent material has the cubic phase. Relevant alkaline earth cations (M’) are magnesium (Mg), strontium (Sr), calcium (Ca) and barium (Ba), especially one or more of Sr and Ba.

[0103] In an embodiment, a combination of different alkaline cations may be applied. In yet another embodiment, a combination of different alkaline earth cations may be applied. In yet another embodiment, a combination of one or more alkaline cations and one or more alkaline earth cations may be applied. For instance, KRbo.sSro^sAXe might be applied. As indicated above, x may be in the range of 0-1, especially x<l. In an embodiment, x=0.

[0104] The term “tetravalent manganese” refers to Mn4+. This is a well-known luminescent ion. In the formula as indicated above, part of the tetravalent cation A (such as Si) is being replaced by manganese. Hence, M’xM2-2xAX6 doped with tetravalent manganese may also be indicated as M’xM2-2xAi-mMnmX6. The mole percentage of manganese, i.e. the percentage it replaces the tetravalent cation A will in general be in the range of 0.1-15 %, especially 1-12 %, i.e. m is in the range of 0.001-0.15, especially in the range of 0.01-0.12.

[0105] A comprises a tetravalent cation, and preferably at least comprises silicon. A may optionally (further) comprise one or more of titanium (Ti), germanium (Ge), stannum (Sn) and zinc (Zn). Preferably, at least 80%, even more preferably at least 90%, such as at least 95% of M consists of silicon. Hence, in a specific embodiment, M’xM2-2xAX6 may also be described as M’xM2-2xAi-m-t-g-s-zrMnmTitGegSnsZrzrX6, wherein m and x are as indicated above, and wherein t,g,s,zr are each individually preferably in the range of 0-0.2, especially 0-0.1, even more especially 0-0.05, wherein t+g+s+zr is smaller than 1, especially equal to or smaller than 0.2, preferably in the range of 0-0.2, especially 0-0.1, even more especially 0- 0.05, and wherein A is especially Si. X is preferably fluorine (F).

[0106] As indicated above, M relates to monovalent cations, but preferably at least comprises potassium and / or rubidium. Other monovalent cations that may further be comprised by M can be selected from the group consisting of lithium (Li), sodium (Na), cesium (Cs) and ammonium (NH ). In an embodiment, preferably at least 80%(i.e. 80% of all moles of the type M), even more preferably at least 90%, such as 95% of M consists of potassium and / or rubidium. Especially, in these embodiments x is thus zero.

[0107] In specific embodiments, the luminescent material may comprise (K,Rb)2SiFe:Mn4+. Alternatively or additionally, in embodiments the third luminescent material may comprise K2SiFe:Mn4+. Alternatively or additionally, in embodiments the third luminescent material may comprise K2TiFe:Mn4+. In embodiments, the third luminescent 2024PF80076

[0108] 24 material may comprise K2(Si,Ti)Fe:Mn4+. As can be derived from the above, “Si,Ti” may indicate one or more of Si and Ti.

[0109] Hence, when M (or A), etc., may refer to n different elements, with n being at least two, 2n-l permutations may in principle be possible.

[0110] 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.

[0111] 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 nanowires, etcetera.

[0112] 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).

[0113] 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.

[0114] 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 first luminescent material comprising luminescent materials A and B, and a second luminescent material comprising only A or only B, or comprising both A and B, but in a different weight ratio. Such first luminescent material and second luminescent material may have different spectral power distributions of their respective luminescent material light.

[0115] 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” 2024PF80076

[0116] 25 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.

[0117] 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 440-490 nm wavelength range.

[0118] As indicated above, the light generating system may especially be configured to generate system light. In embodiments, the system light may comprise at least part of the 2024PF80076

[0119] 26 first device light that may at least once have been diffused comprising the second linear polarization directed via the first redirection element in the optical path to the light exit. Hence, in embodiments the system light may comprise first device light that may at least once have been diffused comprising the second linear polarization. However, in other embodiments the system light may comprise first device light that may at least once have been diffused that is depolarized or has another polarization. Hence, any first device light that has been diffused by the segmented specular reflecting metallic reflector and is directed via the first redirection element in an optical path to the light exit, and also escapes from the light generating system via the light exit may be first device light that is at least once diffused. Such light may have the second polarization, but may also be unpolarized, or may have undergone a polarization change. Further, such first device light may also have been further diffused, by a second diffuser, see also below. In such embodiments, however, the first device light may especially be indicated as first device light that is at least twice diffused (see further below).

[0120] Further, alternatively or additionally, when the light generating system comprises the luminescent material, the system light may comprise luminescent material light. Therefore, in embodiments, the system light may comprise one or more of (a) at least part of the first device light that may at least once have been diffused, optionally comprising the second linear polarization (directed via the first redirection element in the optical path to the light exit) and (b) the luminescent material light. Hence, in specific embodiments, the system light may comprise, in an operational mode of the light generating system, at least part of the first device light that may at least once have been diffused (optionally comprising the second linear polarization (directed via the first redirection element in the optical path to the light exit)) and the luminescent material light. Hence, in embodiments the light generating system may be configured to generate system light comprising one or more of (a) at least part of the first device light (diffused by the one or more diffusers (comprising the segmented specular reflecting metallic reflector and the second diffuser)) directed via the second diffuser in the optical path to the light exit and (b) the luminescent material light. In embodiments, the system light may be white light (see also below).

[0121] Here below, some further embodiments of the segmented specular reflecting metallic reflector are described.

[0122] The segmented specular reflector provides locally to different angles of incidence for light having the first predetermined angle of incidence (ail) (relative to the cross-sectional plane (see also above). Though a part of the reflector surface may be 2024PF80076

[0123] 27 perpendicular to light with an optical axis having the first predetermined angle of incidence (ail), a substantial part may have (small) deviations, to provide the desired diffusion. To define this, a cross-sectional area of the cross-sectional plane. In embodiments, the segmented specular reflecting metallic reflector comprises a cross-sectional plane (P) having a reflector cross-sectional area Al, wherein the segmented specular reflecting metallic reflector comprises a reflective surface, wherein for at least ql% of the reflector cross- sectional area Al applies that an angle (a) between a tangent to the reflective surface and a line (V) configured parallel to first device light having the first predetermined angle of incidence (ail) is selected from the range of smaller than pl° and at least p2°. In embodiments, ql may be selected from the range of 20-100%, such as at least about 40%, like selected from the range of 60-100%, like at least about 80%. In embodiments ql may be 100%, and in other embodiments, ql may be equal to or less than 95%, such as at maximum about 90%. Further, in embodiments pl may especially be 90, and p2 may be selected from the range of 30-70, such as selected from the range of 40-60. In specific embodiments, the segmented specular reflecting metallic reflector comprises a cross-sectional plane (P) having a reflector cross-sectional area Al, wherein the segmented specular reflecting metallic reflector comprises a reflective surface, wherein for at least 80% or at least 90% of the reflector cross-sectional area Al applies that an angle (a) between a tangent to the reflective surface and a line (V) configured parallel to first device light having the first predetermined angle of incidence (ail) is selected from the range of smaller than 85° and at least 55°. There may be an plurality of different angles (a) over the cross-sectional area Al. In this way a relatively smooth angular distribution of the diffused light may be obtained. Note that line (V) is not necessarily perpendicular to the plane P, but in embodiments may be.

[0124] The segments may be relatively small, for instance when the segments are provided by cured structures. Alternatively or in addition to curved structures, facetted structures may be applied. Hence, in embodiments the segmented specular reflecting metallic reflector comprises a reflective surface, wherein the reflective surface comprises curved surface segments. For instance, for a relatively small diffusion angle, circle or hexagonal segment like structures could be applied having heights that are a fraction of the diameter (e.g. selected from the range of 2-60%, such as selected from the range of 5-60%, or less). Note that in embodiments there may be a distribution of dimensions of the facetted structures, such as at least three different values. Alternatively or additionally, in embodiments the segmented specular reflecting metallic reflector comprises a facetted metallic reflector, wherein the reflective surface comprises a plurality of facets having mutual 2024PF80076

[0125] 28 top angles (pi), especially selected from the range of larger than 90° and smaller than 170°, such as selected from the range of larger than 95° and smaller than 170°. Whereas in the curved embodiments, there may be a distribution of angles of reflection by definition, when applying relatively flat facets, there may be a distribution of mutual top angles (pi). In this way a relatively smooth angular distribution of the diffused light may be obtained.

[0126] Especially, the structures that provide the segments are selected such and shaped such, that under the first predetermined angle of incidence (ail) a large part of the light is reflected without any additional reflection at the segmented specular reflecting metallic reflector, and thus only a small part, if any, may be reflected with an additional reflection at the segmented specular reflecting metallic reflector. In this way, the linear polarization may essentially be maintained. Hence, in specific embodiments the segmented specular reflecting metallic reflector may be configured such that of coherent monochromatic light having a wavelength selected from a wavelength dependent spectral power distribution of the first device light incident on the segmented specular reflecting metallic reflector under the first predetermined angle of incidence (ail) (on the segmented specular reflecting metallic reflector (610 less than 10%, such as less than 5% is reflected more than once at the segmented specular reflecting metallic reflector.

[0127] The one or more diffusers comprised by the light generating system may in embodiments essentially consist of the segmented specular reflecting metallic reflector (only). Hence, the embodiment of “one or more diffusers” may refer to a single diffuser (i.e. the segmented specular reflecting metallic reflector). However, in other embodiments, the one or more diffusers may comprise in addition to the segmented specular reflecting metallic reflector one or more (other) diffusers. Especially, in embodiments the light generating system further comprise a transmissive diffuser. Such further diffuser may be configured in an optical path between the first light generating device and the first diffuser arrangement, but may alternatively be configured in an optical path between the first diffuser arrangement and the light exit. Especially, in embodiments the one or more diffusers may further comprise a second diffuser, wherein the second diffuser may be a transmissive diffuser; wherein the second diffuser may especially be configured downstream of the first diffuser arrangement and upstream of the light exit. Further, in embodiments the second diffuser may be configured in an optical path between the first redirection element and the light exit. Further, in embodiments the transmissive diffuser may comprise one or more of volume diffuser and a surface diffuser. Yet, in embodiments the second diffuser may be configured to further diffuse the first device light that may at least once have been diffused received via the first 2024PF80076

[0128] 29 diffuser into first device light that may at least twice have been diffused. In this way, the diffused device light escaping from the light generating system may comprise (or essentially consist of) the first device light that may at least twice have been diffused.

[0129] The phrase “first device light that may at least twice have been diffused”, and similar phrases, may especially refer to first device light that has at least been diffused by the segmented specular reflecting metallic reflector and (subsequently) by the second diffuser.

[0130] Especially, in embodiments the (transmissive) second diffuser may have a second full width half maximum diffusion angle (02) for coherent light under a second predetermined angle of incidence (ai2) (on the second diffuser). Further, in embodiments the second full width half maximum diffusion angle (92) may be larger than the first full width half maximum diffusion angle (91). Alternatively or additionally, in embodiments the second full width half maximum diffusion angle (92) may be selected from the range of 0.5-40°, more especially 1-20°. The light generating system may be configured such that an optical axis of the (first device) light to be diffused by the (transmissive) second diffuser has an angle of incidence of (essentially) 0° (i.e. perpendicular irradiation). In embodiments, for instance, at least 60% or at least 80% of the spectral power of the incident light, may be diffused (i.e. diffusively transmitted).

[0131] Especially, in embodiments the second full width half maximum diffusion angle (92) may be larger than the first full width half maximum diffusion angle (91). For instance, in embodiments 92 / 91>l .05. In embodiments, 02>1.1*01, such as 02>1.2*01. For instance, in embodiments 1.05<92 / 91<4, like 1.2<92 / 91<2.5. For instance, in (other) embodiments 92>(91+5°), such as in embodiments 92>(91+5°). Yet, in embodiments 92<(91+35°).

[0132] The first device light escaping from the system may diffused by the first diffuser arrangement only, and may in specific embodiments (then) comprise the second linear polarization. However, the diffused first device light, only once diffused, escaping from the light generating system may also be depolarized.

[0133] Likewise, when the one or more diffusers may comprise in addition to the segmented specular reflecting metallic reflector the (transmissive) second diffuser, the first device light that may at least twice have been diffused escaping from the system may in specific embodiments (then) comprise the second linear polarization. However, the first device light that may at least twice have been diffused escaping from the light generating system may also be depolarized. 2024PF80076

[0134] 30

[0135] For obtaining depolarized light, a depolarizer may be applied. Possible examples of depolarizers are e.g. transmissive diffusers, fiber optics, and semitransparent materials. Hence, in embodiments the (transmissive) second diffuser may further be configured to further depolarize the first device light that may at least once have been diffused received via the first diffuser into depolarized first device light that may at least twice have been diffused. Hence, a transmissive diffuser may be depolarizing or may be polarization maintaining.

[0136] In specific embodiments, the (diffused) first device light originating from the facetted reflector and imping on the second diffuser may be light essentially having a single polarization. In further specific embodiments, at least 30% or at least 40% e.g. about 50% of the light exiting the second diffuser may have a different polarization. Such percentages may be based on spectral powers (e.g. <70% of the spectral power having the same polarization, and >30% of the spectral power having a different polarization).

[0137] Hence, in embodiments the first device light, at least once or at least twice diffused, escaping from the light generating system (via the light exit) may be depolarized light, and in other embodiments the first device light, at least once or at least twice diffused, escaping from the light generating system (via the light exit) may comprise linearly polarized light.

[0138] As can be derived from the above, the first device light emanating from the segmented specular reflecting metallic reflector may have a full width half maximum (FWHM) beam width of in the order of about 1-40°. The beam angle of the first device light (at least once diffused) may be reduced further in the light generating system by using one or more (further) collimator elements configured in the optical path between the segmented specular reflecting metallic reflector and the light exit. Especially, in embodiments in the optical path between the specular reflecting metallic reflector and the first redirection element, one or more collimator elements may be configured.

[0139] Hence, the first device light diffused by the segmented specular reflecting metallic reflector and reaching the second diffuser may be collimated light. This first device light may then be further diffused by the second diffuser. In embodiments, the first device light emanating from the second diffuser (in an optical path to the light exit) may have a full width half maximum (FWHM) beam width of in the order of about 1-40°.

[0140] However, the beam angle of the first device light downstream from the second diffuser may be reduced further in the light generating system by using one or more (further) collimator elements (see further also below). For instance, in embodiments the optics 2024PF80076

[0141] 31 comprise one or more (further) collimating optical elements, wherein the first light generating device and the optics may be selected and configured such that first device light escaping from the light generating system via the light exit may have upon escape from the light exit a system light full width half maximum diffusion angle (0SF) selected from the range of 0.1-3°. Especially, in embodiments first device light escaping from the light generating system via the light exit may have upon escape from the light exit a system light full width half maximum diffusion angle (0SF) selected from the range of 0.1-2°, such as selected from the range of 0.1-1°.

[0142] Such further collimating optical elements may be configured downstream of the second diffuser and upstream of the light exit. However, the light exit may also be defined by a collimating optical element.

[0143] 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.

[0144] With the proposed light generating system, the light output may be relatively high, whereas the radiance may still be at acceptable levels, or even lower, than some light bulbs.

[0145] As indicated above, the system light may in embodiments comprise luminescent material light. To this end, the light generating system may comprise a luminescent material (and (optionally) the second light generating device as pump light source). Relative to the light with which the luminescent material is pumped, the luminescent material may be configured in the reflective mode or in the transmissive mode.

[0146] The luminescent material may be configured in the reflective mode or in the transmissive mode. In the transmissive mode, it may be relatively easy to have light source light admixed in the luminescent material light, which may be useful for generating the desirable spectral power distribution. In the reflective mode, thermal management may be more easy, as a substantial part of the luminescent material may be in thermal contact with a thermally conductive element, like a heatsink or heat spreader. In the reflective mode, a part of the light source light may in embodiments be reflected by the luminescent material and / or 2024PF80076

[0147] 32 a reflector and may be admixed in the luminescent material light. The reflector may be configured downstream of the luminescent material (in the reflective mode). In the reflective mode, a dichroic reflector may be used, to promote the luminescent material light over the device light. The former may be transmitted with a higher transmission than the latter and the latter may be reflected with a higher reflection than the former (see further also below).

[0148] Hence, in embodiments the light generating system may further comprising a second redirection element, and the luminescent material may be configured in the reflective mode. Especially, in embodiments the second redirection element may be configured in an optical path between the first redirection element and the light exit and in an optical path between the second luminescent material and the light exit. In embodiments, the second redirection element may be configured to direct (a) first device light that may at least once have been diffused or optionally at least twice have been diffused, received by the second redirection element via the first redirection element, and (b) direct luminescent material light received by the second redirection element, in an optical path to the light exit. Yet further, the second redirection element may be configured in an optical path between (the source of pump light for the luminescent material, especially) the second light generating device and the luminescent material. Further, in embodiments the second redirection element may comprise a dichroic beam combiner or other type of combiner.

[0149] Hence, in specific embodiments the light generating system may further comprise a dichroic element, configured to transmit or reflect the light from a light source and configured to reflect or transmit the luminescent material light (generated by the luminescent material e.g. due to conversion of the light from the light source).

[0150] Hence, in a light generating system comprising a source of light, like a light generating device (e.g. comprising a solid state light source) that emits light having a first wavelength range along a first beam path, a wavelength converting element may be configured in the first beam path. Such wavelength converting element may in embodiments be physically separated from source of light. Further, such wavelength converting element may be configured to convert at least part of the light having a first wavelength range into light having a second wavelength range along a second beam path. Especially, in embodiments a color separation element, especially a dichroic element, may be disposed between the source of light and the wavelength converting element. In embodiments, the color separation element may be configured to prevent substantially all of the light having the second wavelength range from being incident on the source of light. Hence, such color separation element may in embodiments be configured to (a) transmit at least part of the light 2024PF80076

[0151] 33 having the first wavelength range and reflect at least part of the light having the second wavelength range, or (b) reflect at least part of the light having the first wavelength range and transmit at least part of the light having the second wavelength range.

[0152] A multichroic beam splitter (such as a dichroic beam splitter) may be considered an example of (multichroic based) redirection optics or (multichroic based) redirecting optics. Light propagating to the multichroic beam splitter, and comprising intensity at different spectral positions, like light having a broad spectral power distribution, or light having different spectral peaks, or like light comprising a combination of first light having a first centroid wavelength and second light having a second centroid wavelength, different from the first centroid wavelength, etc., may be split in two orthogonally propagating beams of light with different spectral power distributions (or complementary spectral power distributions). Hence, this provides the multichroic beam splitter its beam splitting function. However, the opposite may also be true, two beams of light with different spectral power distributions orthogonally propagating to the multichroic beam splitter may be combined in a single beam comprising both spectral power distributions and propagating along an axis parallel to an axis of one of the two beams of light with spectral power distributions orthogonally propagating to the multichroic beam splitter. Hence, the term multichroic beam splitter may also refer to a multichroic beam combiner.

[0153] Hence, for the multichroic beam splitter may apply that for a first wavelength range, the wavelength averaged transmission may be higher, like at least 10% points higher, such as at least 20% points higher, or even at least 30 % points, than for a second wavelength range (different from the first wavelength range). Similarly, for a first wavelength range, the wavelength averaged reflection may be lower, like at least 10% points lower, such as at least 20% points lower, or even at least 30 % points, than for a second wavelength range. Especially, in embodiments, the multichroic 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 (first) light having the first wavelength to a first direction and at least 60%, like at least 80%, more especially at least 90%, such as at least about 95%, of (second) light of the second wavelength to a second direction, wherein the directions may in embodiments have a mutual angle selected from the range 45-135°, such as about 90°. In embodiments, the first light may have a first centroid wavelength and the second light may have a second centroid wavelength, which may differ at least 5 nm, more especially at least about 10 nm. In embodiments the centroid wavelengths may differ at least about 15 nm. The percentage of the light may refer to a spectral power (e.g. in Watt). 2024PF80076

[0154] 34

[0155] In embodiments, the term “multichroic beam splitter”, and similar terms may refer to a dichroic beam splitter.

[0156] The multichroic beam splitter, especially the dichroic beam splitter, may be an embodiment of a color separation element, such as described in US7070300, which is herein incorporated by reference. Especially, the color separation element may be selected from the group of a dichroic mirror, a dichroic cube, and a diffractive optical element. Optionally, the color separation element may be provided using a hologram. Especially, the multichroic beam splitter may be a dichroic mirror or reflector.

[0157] A dichroic beam splitter or dichroic beam combiner may in embodiments be configured combine two different types of light, e.g. in a 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. in a 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 combiner, 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. combining).

[0158] In embodiments, the second redirection element may be configured to transmit (a) first device light that may at least once have been diffused, or optionally at least twice have been diffused, received by the second redirection element via the first redirection element, and (b) reflect luminescent material light received by the second redirection element, in an optical path to the light exit. Further, the second redirection element may be configured to direct second device light, received by the second redirection element, in an optical path to the luminescent material. More especially, the second redirection element may be configured to transmit second device light, received by the second redirection element, in an optical path to the luminescent material. Note that herein instead of a single second redirection element, also more than one second redirection element may be applied. In such embodiments, a primary second redirection element may be configured to separate the second device light from the luminescent material light, and a secondary second redirection element may be configured to combine at least part of this luminescent material light with the 2024PF80076

[0159] 35 first device light that may at least once have been diffused, or at least twice have been diffused.

[0160] In other embodiments, however, the luminescent material is configured in the transmissive mode. In such embodiments, a second redirection element may be configured to combine at least part of this luminescent material light with the first device light that may at least once have been diffused optionally comprising the further diffused device light.

[0161] As indicated above, with the current invention it may be possible to better tune beam sizes and full width half maximum beam angles of the luminescent material light and the diffused first device light. The full width half maximum beam angle of the diffused device light may e.g. better be matched with the full width half maximum beam angle of the luminescent material light. In specific embodiments, the optics are selected and configured such that the first device light that may at least once have been diffused, or at least twice have been diffused, upon escape from the light exit may have a first cross sectional area (Al) defined by the full width half maximum of the first device light, the luminescent material light upon escape from the light exit has a second cross sectional area (A2) defined by the full width half maximum of the luminescent material light, and wherein either the first cross sectional area (Al) and the second cross sectional area (A2) fully overlap each other or wherein at least 60%, such as at least 70%, like at least 80%, of the larger of the cross sectional areas (A1,A2) overlaps with at least 60%, such as at least 70%, like at least 80% of the smaller of the cross sectional areas (A1,A2). Hence, in embodiments at least 80% of the larger of the cross sectional areas (A1,A2) overlaps with at least 80% of the smaller of the cross sectional areas (A1,A2). In specific embodiments, embodiments at least 90% of the larger of the cross sectional areas (A1,A2) overlaps with at least 90% of the smaller of the cross sectional areas (A1,A2). Note that it is also possible that e.g. at least 80% of the larger of the cross sectional areas (A1,A2) overlaps with at least 90% of the smaller of the cross sectional areas (A1,A2), or at least 80% of the larger of the cross sectional areas (A1,A2) overlaps with 100% of the smaller of the cross sectional areas (A1,A2). When 100% of the larger of the cross sectional areas (A1,A2) overlaps with 100% of the smaller of the cross sectional areas (A1,A2), the cross sectional areas (A1,A2) are thus the same. In specific embodiments, O.9<A1 / A2<1.1, such as especially in embodiments 0.95<Al / A2<1.05. For instance, in further specific embodiments, 0.98<Al / A2<1.02.

[0162] Further, the optics may comprise one or more lenses (see also above). Especially, in embodiments the light generating system may further comprise a first lens, wherein the first lens is configured between the retarder element and the specular reflecting 2024PF80076

[0163] 36 metallic reflector. In this way, further the beam size of the first device light that may at least once have been diffused may be controlled.

[0164] In embodiments, the spot on the specular reflecting metallic reflector (but also on the second diffuser) may be (very) small. Hence, an optical element, like afore-mentioned first lens, may be used to focus the first device light on the specular reflecting metallic reflector (and the facetted mirror diffuses the light). As indicated above, the diffused light, diffused via the specular reflecting metallic reflector, may be collimated again by the same optical element. To some extend similarly, this may apply to the first device light propagating via the second diffuser. The spot on the second diffuser may (also) be (very) small. Hence, an optical element, like a lens, may be used to focus the first device light (received via the specular reflecting metallic reflector) on the second diffuser (and the second diffuser transmits and (further) diffuses the first device light). As indicated above, the diffused light, diffused via second diffuser, may be collimated again, but (then) by an optical element configured downstream of the second diffuser.

[0165] In specific embodiments, the system light may thus comprise, in an operational mode of the light generating system, (a) the first device light that may at least once have been diffused, optionally at least twice diffused, and (b) the luminescent material light. Further, in embodiments, the system light may be white light having a correlated color temperature selected from the range of 1500-12000 K, such as having a CCT of at least 2000 K, more especially at least 3000 K. Yet, in embodiments the system light is white light having a color rendering index of at least 65, such as at least about 70, like at least about 80, more especially at least about 85. Hence, in embodiments the system light may be white light having a correlated color temperature selected from the range of 1500-12000 K and a color rendering index of at least 65.

[0166] 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. 2024PF80076

[0167] 37

[0168] 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.

[0169] Yet, as indicated above, in embodiments the light generating system may further comprises a control system configured to (individually) control the first light generating device and the second light generating device.

[0170] 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.

[0171] Yet, in embodiments, the first device light may comprise one or more of blue light, orange light, and red light. With the appropriate multichroic second redirection element, they may all be combined with the luminescent material light, thereby providing in embodiments white system light. To this end, two or more different first light generating devices may be applied, to generate first device light having different peak wavelengths. Alternatively or additionally, the luminescent material may comprise two or more different types of luminescent materials, providing luminescent material light having in spectral power in different wavelength ranges (like in the red and orange, or in the red and yellow, etc.). Alternatively or additionally, the combination of a second light generating device with a luminescent material, of which the luminescent material light is combined via a second 2024PF80076

[0172] 38 redirection element may be configured at one further positions within the system, wherein each combination has a differ type of luminescent material. Also in this way different colors of light may be provided.

[0173] In embodiments, the second device light may comprise one or more of violet and blue light. This may be used to pump the luminescent material. In specific embodiments, the luminescent material at least comprises a luminescent material of the type AsBsOn Ce3, 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 (see also above).

[0174] As can be derived from the above, in yet other embodiments, the light generating device may comprise the luminescent material, but not the second light generating device. Further, in yet further specific embodiment, the part of the first device light may be branched off, e.g. using a partial transmissive and partial reflective optical element, or other means known to the person skilled in the art. The branched off part may be directed (in embodiments via one or more optical elements of the optics) to the luminescent material. In such embodiments, the luminescent material may be configured to convert at least part of the first device light, branched off in an optical path to the luminescent material, and received by the luminescent material, into luminescent material light. Further, such embodiments may still be combined with embodiments where the second light generating device is available. In such yet further specific embodiments, the luminescent material may (then) be configured to convert the first device light, received by the luminescent material, and the second device light, received by the luminescent, into luminescent material light. As indicated herein, the first light generating device may e.g. comprise a plurality of laser diodes. Hence, when branching off first device light, it may in specific embodiments still be possible to individually control the spectral power of the first device light directed in an optical path to the first diffuser and the spectral power of the first device light directed in an optical path to the luminescent material.

[0175] Further, as can be derived from the above, in yet other specific embodiments, the light generating system may neither comprise the luminescent material, nor the second light generating device.

[0176] 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, 2024PF80076

[0177] 39 indicator sign systems, decorative lighting systems, portable systems, automotive applications, (outdoor) road lighting systems, urban lighting systems, greenhouse 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.

[0178] 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.

[0179] 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 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] 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.

[0181] 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, that can only operate in a single operation mode (i.e. “on”, without further tunability). 2024PF80076

[0182] 40

[0183] 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.

[0184] 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 the first light generating device and the optics, the optional second light generating device, the optional luminescent material, etc.

[0185] 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 and the optics, the optional second light generating device, the optional luminescent material, etc. and the light generating system may further comprise e.g. a control system configured to control the device.

[0186] 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 2024PF80076

[0187] 41 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.

[0188] In embodiments, the lamp or luminaire may be a downlighter or an uplighter. In embodiments, the lamp may comprise a torch.

[0189] Herein, the term “visible light” especially relates to light having a wavelength selected from the range of 380-780 nm.

[0190] 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 Ac = 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.

[0191] BRIEF DESCRIPTION OF THE DRAWINGS

[0192] 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:

[0193] Figs, la-lb schematically depict some embodiments, and

[0194] Figs. 2a-2c schematically depict some aspects.

[0195] Fig. 3 schematically depicts some (application) embodiments.

[0196] The schematic drawings are not necessarily to scale.

[0197] DETAILED DESCRIPTION OF THE EMBODIMENTS

[0198] Figs, la-lb schematically depict embodiments of a light generating system 1000 comprising a first light generating device 110, a second light generating device 120, optics 500, a luminescent material 200, and a light exit 1090. Especially, the first light generating device 100 may be configured to generate first device light 111. Furthermore, in embodiments, the first light generating device 110 may comprise one or more of a laser diode, a superluminescent diode, and a multi -junction diode. Moreover, in embodiments, the first device light 111 may have spectral power at one or more wavelengths selected from the range of 380-780 nm. Further, in embodiments, the optics 500 may comprise a one or more diffusers 600. In specific embodiments, the one or more diffusers 600 may be configured to 2024PF80076

[0199] 42 diffuse the first device light 111, received by the one or more diffusers 600, upstream of the light exit 1090.

[0200] In embodiments, the one or more diffusers 600 at least may comprise a segmented specular reflecting metallic reflector 610. Moreover, in embodiments, the segmented specular reflecting metallic reflector 610 may have a first full width half maximum diffusion angle 01 for coherent light under a first predetermined angle of incidence ail (on the segmented specular reflecting metallic reflector 610). Especially, the first full width half maximum diffusion angle (91) may be selected from the range of 1-20°; see also Figs. 2a-2c.

[0201] In embodiments, the first light generating device and the optics 500 (including the one or more diffusers 600) may be selected and configured such that first device light 111 escaping from the light generating system 1000 via the light exit 1090 as first device light 111 that may at least once have been diffused may (in an operational mode of the light generating system 1000) have upon escape from the light exit 1090 a system light full width half maximum diffusion angle (9SF) selected from the range of 0.1-3°. To this end, the optics 500 may also comprise collimating optical elements, see also below.

[0202] In further embodiments, the optics 500 may comprise a first redirection element 510 and a first diffuser arrangement 601. Furthermore, in embodiments, the first redirection element 510 may be configured in an optical path between the first light generating device 110 and the first diffuser arrangement 601.

[0203] Especially, the light generating system 1000 may be configured such that the first device light 111 reaching the first redirection element 510 may comprise a first linear polarization. Moreover, in embodiments, the first diffuser arrangement 601 may comprise a retarder element 550 and the specular reflecting metallic reflector 610. Furthermore, in embodiments, the retarder element 550 may comprise a X / 4 plate. Further, in embodiments, the retarder element 550 may be configured in an optical path between the first redirection element 510 and the specular reflecting metallic reflector 610.

[0204] Furthermore, in embodiments, the first diffuser arrangement 601 may be configured to convert first device light 111 comprising the first linear polarization, received by the diffuser arrangement 1700, into first device light 111 that may at least once have been diffused comprising a second linear polarization, different from the first linear polarization. Moreover, in embodiments, the first redirection element 510 may be configured (a) to direct the first device light 111 that may comprise a first linear polarization, reaching the first redirection element 510, in an optical path to the first diffuser arrangement 601, and (b)) to 2024PF80076

[0205] 43 direct the first device light 111 that may at least once have been diffused (by the specular reflecting metallic reflector 610) comprising the second linear polarization, reaching the first redirection element 510, in an optical path to the light exit 1090.

[0206] Especially, the second light generating device 120 may be configured to generate second device light 121. Yet, in embodiments, the second light generating device 120 may comprise one or more of a laser diode, a superluminescent diode, and a multijunction diode. In further embodiments, the second device light 121 may have spectral power at one or more wavelengths selected from the range of 380-490 nm.

[0207] Especially, the luminescent material 200 may be configured to convert at least part of the second device light 121, received by the luminescent material 200, into luminescent material light 201.

[0208] Further, 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 first device light 111 that may at least once have been diffused comprising the second linear polarization directed via the first redirection element 510 in the optical path to the light exit 1090 and (b) the luminescent material light 201 (especially comprising in an operational mode of the light generating system 1000 at least part of the first device light 111 that may at least once have been diffused comprising the second linear polarization directed via the first redirection element 510 in the optical path to the light exit 1090 and the luminescent material light 201). However, the first device light 111 escaping from the light generating system 1000 may also be depolarized, e.g. by using a depolarizer, or have another polarization, e.g. by using a 1 / 2X plate, etc.

[0209] Referring again to Figs, la-lb, in embodiments the one or more diffusers 600 may further comprise a second diffuser 620. In further embodiments, the second diffuser 620 may be a transmissive diffuser. Moreover, in embodiments, the second diffuser 620 may be configured downstream of the first diffuser arrangement 601 and upstream of the light exit 1090. In embodiments, the second diffuser 620 may be configured in an optical path between the first redirection element 510, see also above, and the light exit 1090). In embodiments, the transmissive diffuser may comprise one or more of volume diffuser and a surface diffuser. Especially, the second diffuser 620 may be configured to further diffuse first device light 111 that may at least once have been diffused received via the first diffuser 610 into first device light 11 Ithat may at least twice have been diffused. Hence, in embodiments, the diffused device light 111 escaping from the light generating system 1000 may comprise the first device light 111 that may at least twice have been diffused. 2024PF80076

[0210] 44

[0211] In further embodiments, the first light generating device 110 and the optics 500 (including the one or more diffusers 600) may be selected and configured such that first device light 111 escaping from the light generating system 1000 via the light exit 1090 as first device light 111 that may at least once have been diffused comprising the second linear polarization may, in an operational mode of the light generating system 1000, have upon escape from the light exit 1090 a system light full width half maximum diffusion angle (0SF) selected from the range of 0.1-3° (see also above and below).

[0212] Furthermore, in embodiments, the (transmissive) second diffuser 620 may be further configured to further depolarize the first device light 111 that may at least once have been diffused received via the first diffuser 610 into depolarized first device light that may at least twice have been diffused 111.

[0213] Referring to Figs, la-lb, in embodiments, the light generating system 1000 may further comprise a second redirection element 520.

[0214] Referring to Fig. la, in embodiments, the luminescent material 200 may be configured in the reflective mode. Furthermore, in embodiments, the second redirection element 520 may be configured in an optical path between the first redirection element 510 and the light exit 1090 and in an optical path between the second luminescent material 200 and the light exit 1090. Referring to Fig. lb, in embodiments, the luminescent material 200 may be configured in the transmissive mode.

[0215] Referring to Figs, la-lb, in embodiments the light generating system 1000 may further comprise a first lens 530. Especially, the first lens 530 may be configured between the retarder element 550 and the specular reflecting metallic reflector 610.

[0216] Further, in embodiments, the system light 1001 may comprise, in an operational mode of the light generating system 1000, (a) the first device light 111 that may at least once have been diffused or the first device light 111 that may at least twice have been diffused, as defined herein, and (b) the luminescent material light 201.

[0217] Especially, in embodiments, the system light 1001 may be white light having a correlated color temperature selected from the range of 1500-12000 K and a color rendering index of at least 65.

[0218] Furthermore, in embodiments, the light generating system 1000 may further comprise a control system 300 configured to (individually) control the first light generating device 110 and the second light generating device 120. 2024PF80076

[0219] 45

[0220] In embodiments, the first device light 111 may comprise one or more of blue light, orange light, and red light. Further, in embodiments, the second device light 121 may comprise one or more of violet and blue light.

[0221] Yet, in embodiments, the luminescent material 200 at least may comprise a luminescent material of the type AsBsOn Ce3. Especially, A may comprise one or more of Y, La, Gd, Tb and Lu. Especially, B may comprise one or more of Al, Ga, In and Sc.

[0222] Further, in embodiments, the first light generating device 110 may comprise a first laser bank comprising a plurality of first lasers 10. Especially, the second light generating device 120 may comprise a second laser bank comprising a plurality of second lasers 20.

[0223] Several elements may be optional. For instance, the elements in the dashed boxes in Figs, la-lb may be optional, but other elements may also be optional. For instance, the second diffuser 620 may be optional. Some specific optics 500 depicted may be optional or may be replaced with similar optical elements.

[0224] The optical elements 500 of the light generating system 1000 may especially comprise one or more condensing and / or collimating optics. For example, as depicted here, the optical elements 500 may comprise a lens 560, or a plurality of (micro) lenses 560, configured between the first light generating device 110 and the first redirection element 510, and / or between the second light generating device 120 and the second redirection element 520. Alternatively or additionally, a lens 560, or a plurality of (micro) lenses 560, may be configured in the optical path between the second redirection element 520 and the light exit 1090, or they may provide the light exit 1090.

[0225] The optical elements 500 of the light generating system 1000 may further comprise a lens 570, or a plurality of (micro) lenses 570, configured upstream and downstream of the (optional) second diffuser 620. Lenses 570 may be configured to converge or diverge light. For instance, lens 570 downstream of the second diffuser 620 may be configured to collimate the first device light.

[0226] As indicated above, the lens in front of the segmented specular reflecting metallic reflector 610 may be configured to focus first device light 111, such as laser light, onto the segmented specular reflecting metallic reflector 610, but may thus also configured to collimate the diffused first device light 111 made by the facetted segmented specular reflecting metallic reflector 610.

[0227] In similar vein, the first or upstream configured lens 570 may be configured to (receive a substantially parallel beam of (diffused) first device light and) focus the first 2024PF80076

[0228] 46 device light, such as laser light, onto the transmissive diffuser 620, while the second or downstream configured lens 570 may be configured to collimate again the diffused light into (a substantially parallel) beam of first device light 111.

[0229] In embodiments, optics 560 may be configured to collimate system light onto e.g. a wall. By adapting the lens a larger and smaller beam projected onto the wall can be established. In specific embodiments, such collimation may be controllable (via the control system 300).

[0230] Hence, the full width half maximum beam angle of the first device light 111 upstream of lens(es) 560 directly downstream of the first light generating device 110, indicated with reference 0SO1, may be larger than the full width half maximum beam angle of the first device light 111 directly downstream of this (these) lens(es) 560. This latter full width half maximum beam angle of the first device light I l l is indicated with reference 9S02. The full width half maximum beam angle 9S02 of the first device light 111 may be in the order of 0.1-5 °, such as 0.1-3°. In embodiments, 9S01 > (9S02 + 5°).

[0231] Reference 9S11 may refer to the full width half maximum beam angle of the first device light 111 diffused via the first diffuser 610, but upstream of the first redirection element 510. Reference 9S12 may refer to the full width half maximum beam angle of the first device light 111 diffused via the first diffuser 610, downstream of the first redirection element 510, but upstream of the second diffuser 620, and here also upstream of the optical element 570 (in the drawing left of the second diffuser 620).

[0232] The full width half maximum beam angle 9S12 in Fig. 1A may be reduced by a collimating optical element 530. In specific embodiments, 9S11 > (9S12 + 5°).

[0233] A full width half maximum beam angle 9S21 is of the first device light 111 directly downstream of the second diffuser 620, but upstream of the optical element 570 (in the drawing right of the second diffuser 620), whereas reference 9S22 refers to the full width half maximum beam angle 9S21 is of the first device light 111 downstream of the second diffuser 620 and downstream of the optical element 570 (in the drawing right of the second diffuser 620). The full width half maximum beam angle 9S22 of the first device light 111 may be in the order of 0.1-5 °, such as 0.1-3°. Further, in specific embodiments, 9S21 > (9S22 + 5°).

[0234] However, also further collimating optical elements may be applied, see optical elements 560, leading to the system light 1001 escaping from the light generating system 1000 via light exit 1090 that may comprise first device light 111, at least once, or at least twice diffused, having a full width half maximum beam angle 9SF of in embodiments at 2024PF80076

[0235] 47 maximum about 3°. Hence, in embodiments the optics may comprise one or more collimating optical elements 530,560,570, wherein the first light generating device 110 and the optics 500 are selected and configured such that, in an operational mode of the light generating system 1000, first device light 111 escaping from the light generating system 1000 via the light exit 1090 has upon escape from the light exit 1090 a system light full width half maximum diffusion angle 0SF selected from the range of 0.1-3° 0.1-5°.

[0236] However, other configurations and additional optical elements 500 may be possible as well, see e.g. further below.

[0237] The first device light, at least once diffused device light, and at least twice have been diffused, are all indicated with reference 111. For further distinction, in the drawing reference 11 Idf is used to indicate once diffused device light, and reference 11 ldf2 is used to indicate twice diffused further device light. In the schematically depicted embodiments of Figs, la-lb, the (diffused) first device light 111 escaping via the light exit 1090 may essentially consist of the at least twice diffused further device light 111 df2. However, note that the second diffuser 620 is optional.

[0238] Referring to embodiments such as schematically depicted in Figs, la-lb, the spot on the specular reflecting metallic reflector (but also on the second diffuser 620) may be (very) small. Hence, an optical element, like afore-mentioned first lens, may be used to focus the first device light on the specular reflecting metallic reflector (and the facetted mirror diffuses the light). As indicated above, the diffused light, diffused via the specular reflecting metallic reflector, may be collimated again by the same optical element. To some extend similarly, this may apply to the first device light propagating via the second diffuser. The spot on the second diffuser 620 may (also) be (very) small. Hence, an optical element, like a lens, may be used to focus the first device light (received via the specular reflecting metallic reflector) on the second diffuser (and the second diffuser transmits and (further) diffuses the first device light). As indicated above, the diffused light, diffused via second diffuser, may be collimated again, but (then) by an optical element configured downstream of the second diffuser.

[0239] In the reflective mode, the luminescent material 200 may be in thermal contact with a thermally conductive element and / or may be configured on a movable element, like a rotatable element, like a phosphor wheel (see Fig. la). Basically, the same may apply for the reflector 610, which may be in thermal contact with a thermally conductive element and / or may be configured on a movable element, like a rotatable element, like a reflector wheel. In the transmissive mode, the luminescent material 200 may be in thermal contact with a 2024PF80076

[0240] 48 thermally conductive element and / or may be configured on a movable element, like a rotatable element, like a phosphor wheel (see Fig. lb).

[0241] Though Figs, la-lb schematically depict embodiments comprising the luminescent material 200 and the second light generating device 120, as indicated above, other embodiments may also be possible. As can be derived from the above, in yet other specific embodiments, the light generating system 1000 may neither comprise the luminescent material, nor the second light generating device.

[0242] Fig. 2a schematically depicts two possible embodiments of the specular reflective metallic reflector 610; the embodiments are indicated with references I and II. Note more embodiments may be possible, including hybrid embodiments (combining carved and straight parts) than schematically depicted.

[0243] Referring to Figs. 2a, in embodiments, the segmented specular reflecting metallic reflector 610 may comprise a cross-sectional plane P having a reflector cross- sectional area Al. Especially, the segmented specular reflecting metallic reflector 610 may comprise a reflective surface 611. Furthermore, in embodiments, for at least 80% of the reflector cross-sectional area Al may apply that an angle (a) between a tangent to the reflective surface 611 and a line V configured parallel to first device light 111 having the first predetermined angle of incidence ail may be selected from the range of smaller than 90° and at least 55°, such as smaller than 85° and at least 55° (like at most 80° and / or at least 60°). Here, line V is depicted vertical to plane P, implying that in these embodiments the first predetermined angle of incidence ail is 0°.

[0244] Furthermore, in embodiments, the segmented specular reflecting metallic reflector 610 may comprise a facetted metallic reflector. The reflective surface 611 may comprise a plurality of facets 622 having mutual top angles pi, especially selected from the range of larger than 90° and smaller than 170°. The mutual top angles pi are especially between adjacent facets 622 (i.e. directly neighboring facets 622), see also embodiment I in Fig. 2a. Further, adjacent facets 622 of the plurality of facets 622 may have mutual bottom angles P2, especially selected from the range of larger than 90° and smaller than 170°, such as selected from the range of larger than 95° and smaller than 170°.

[0245] Referring to embodiment II in Fig. 2a, in further embodiments, the segmented specular reflecting metallic reflector 610 may comprise a reflective surface 611 comprising curved surface segments 623. There may be a plurality of curvatures having a plurality of different radii, though there may also be a dominant radius of the curved surface segments 623. 2024PF80076

[0246] 49

[0247] Embodiment III of Fig. 2a schematically depicts the diffusion of a pencil beam, with 91 indicating the first full width half maximum diffusion angle.

[0248] Especially, the segmented specular reflecting metallic reflector 610 may be configured such that of coherent monochromatic light having a wavelength selected from a wavelength dependent spectral power distribution of the first device light 111 incident on the segmented specular reflecting metallic reflector 610 under the first predetermined angle of incidence (ail) ((on the segmented specular reflecting metallic reflector less than 5% may be reflected more than once at the segmented specular reflecting metallic reflector 610.

[0249] Furthermore, in embodiments, the segments define maxima and minim. In further embodiments, distances between adjacent maxima may be selected from the range of 1 - 100 pm. Especially, height difference between maxima and adjacent minima may be selected from the range of 0.5 - 50 pm.

[0250] In further embodiments, the first predetermined angle of incidence ail may be in a range from 0° to 2°.

[0251] Referring to Figs. 2a-2b, in embodiments, the (transmissive) second diffuser 620 may have a second full width half maximum diffusion angle 92 for coherent light under a second predetermined angle of incidence ai2) (on the second diffuser 620). Further, in embodiments, the second full width half maximum diffusion angle 92) may be larger than the first full width half maximum diffusion angle 91 (especially wherein the second full width half maximum diffusion angle 92 may be selected from the range of 1-20°.

[0252] Referring to Fig. 2b, schematically is depicted the first full width half maximum diffusion angle 91 of a pencil beam after diffusion by the specular reflecting metallic reflector 610, and also schematically is depicted the second full width half maximum diffusion angle 92 of a pencil beam after diffusion by the (transmissive) second diffuser 620. By way of example, the diffusion of the latter is stronger than of the former, for instance, 92>1.1*91, such as 92>1.2*91. For instance, in embodiments 1.05<92 / 91<4, like 1.2<92 / 91<2.5.

[0253] Referring to Fig. 2b-2c, in embodiments, the optics 500 may be selected and configured such that the first device light 111 that may at least once have been diffused upon escape from the light exit 1090 may have a first cross sectional area Al defined by the full width half maximum of the first device light 111, the luminescent material light 201 upon escape from the light exit 1090 may have a second cross sectional area A2 defined by the full width half maximum of the luminescent material light 201. In further embodiments, either the first cross sectional area Al and the second cross sectional area A2 fully overlap each 2024PF80076

[0254] 50 other or wherein at least 80% of the larger of the cross sectional areas A1,A2 overlaps with at least 80% of the smaller of the cross sectional areas A1,A2. Note that the first device light 111 that may at least once have been diffused may in embodiments essentially consist of first device light that may at least twice have been diffused 111.

[0255] Referring to Figs, la-lb and 2a-2b, it is noted that in Figs, la-lb the beam angles are indicated with 901... 9SF. However, in Fig. 2a ail basically refers to the angle of incidence of a pencil beam, and 91 to the beam angle of the reflected pencil beam, i.e. the diffusion angle of the segmented reflector. Here, perpendicular irradiation is assumed (i.e. optical axis of the incident light and the normal are parallel. Fig 2b shows the diffusion angles of the segmented reflector 91, and of the transmissive diffuser, 92, again assuming a pencil beam (and e.g. assuming perpendicular irradiation). Hence, 91 and 92 are characterizing the diffusers 610,620, whereas the former 9S-values characterize the beam angle of the first device light 111 during propagation through the system 1000 (and exit of the system 1000).

[0256] 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. 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 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. Another embodiment of a lamp may be a torch. 2024PF80076

[0257] 51

[0258] 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. 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.

[0259] 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.

[0260] 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.

[0261] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

[0262] 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 2024PF80076

[0263] 52 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.

[0264] 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.

[0265] 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.

[0266] 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. 2024PF8007653CLAIMS:

1. A light generating system (1000) comprising a first light generating device(110), a second light generating device (120), optics (500), a luminescent material (200), and a light exit (1090), wherein: the first light generating device (100) is configured to generate first device light (111); wherein the first light generating device (110) comprises one or more of a laser diode, a superluminescent diode, and a multi -junction diode; wherein the first device light(111) has spectral power at one or more wavelengths selected from the range of 380-780 nm; the optics (500) comprise one or more diffusers (600), a first redirection element (510), and a retarder element (550); the one or more diffusers (600) are configured in an optical path between the first light generating device (110) and the light exit (1090) and configured to diffuse the first device light (111); wherein the one or more diffusers (600) at least comprises a segmented specular reflecting metallic reflector (610), configured in a light receiving relationship with the first light generating device (110); wherein the segmented specular reflecting metallic reflector (610) has a first full width half maximum diffusion angle (01) for coherent light under a first predetermined angle of incidence (ail), wherein the first full width half maximum diffusion angle (91) is selected from the range of 1-20°; wherein the segmented specular reflecting metallic reflector (610) comprises a cross-sectional plane (P) having a reflector cross-sectional area Al; wherein the segmented specular reflecting metallic reflector (610) comprises a reflective surface (611), wherein for at least 80% of the reflector cross- sectional area Al applies that an angle (a) between a tangent to the reflective surface (611) and a line (V) configured parallel to first device light (111) having the first predetermined angle of incidence (ail) is selected from the range of smaller than 85° and at least 55°; the optics (500) comprise a first diffuser arrangement (601); wherein the first diffuser arrangement (601) comprises the retarder element (550) and the specular reflecting metallic reflector (610); wherein the retarder element (550) comprises a X / 4 plate, wherein the retarder element (550) is configured in an optical path between the first redirection element (510) and the specular reflecting metallic reflector (610); wherein the first diffuser arrangement (601) is configured to diffuse the first device light (111) and change the first2024PF8007654 linear polarization into a second linear polarization, different from the first linear polarization; the first redirection element (510) is configured in an optical path between the first light generating device (110) and the first diffuser arrangement (601); wherein the light generating system (1000) is configured such that the first device light (111) reaching the first redirection element (510) comprises a first linear polarization; wherein the first redirection element (510) is configured (a) to direct the first device light (111) comprising the first linear polarization, reaching the first redirection element (510), in an optical path to the first diffuser arrangement (601), and (b) to direct the first device light (111) comprising the second linear polarization, emanating from the first diffuser arrangement (601) and reaching the first redirection element (510), in an optical path to the light exit (1090); the second light generating device (120) is configured to generate second device light (121); wherein the second light generating device (120) comprises one or more of a laser diode, a superluminescent diode, and a multi -junction diode, wherein the second device light (121) has spectral power at one or more wavelengths selected from the range of 380-490 nm; the luminescent material (200) is configured to convert at least part of the second device light (121), received by the luminescent material (200), into luminescent material light (201); and the light generating system (1000) is configured to generate system light (1001) comprising one or more of (a) at least part of the first device light (111) directed via the first redirection element (510) in the optical path to the light exit (1090) and (b) the luminescent material light (201).

2. The light generating system (1000) according to claim 1, wherein the segmented specular reflecting metallic reflector (610) comprises a facetted metallic reflector, wherein the reflective surface (611) comprises a plurality of facets (622) having mutual top angles (P 1), especially selected from the range of larger than 95° and smaller than 170°.

3. The light generating system (1000) according to claim any one of the preceding claims, wherein the segmented specular reflecting metallic reflector (610) comprises a reflective surface (611), wherein the reflective surface (611) comprises curved surface segments (623).2024PF80076554. The light generating system (1000) according to any one of the preceding claims, wherein the segmented specular reflecting metallic reflector (610) is configured such that of coherent monochromatic light having a wavelength selected from a wavelength dependent spectral power distribution of the first device light (111) incident on the segmented specular reflecting metallic reflector (610) under the first predetermined angle of incidence (ail) less than 5% is reflected more than once at the segmented specular reflecting metallic reflector (610).

5. The light generating system (1000) according to any one of the preceding claims, wherein the segmented specular reflecting metallic reflector (610) comprises maxima and minima, wherein distances between adjacent maxima are selected from the range of 1 - 100 pm, wherein height difference between maxima and adjacent minima are selected from the range of 0.5 - 50 pm.

6. The light generating system (1000) according to any one of the preceding claims, wherein the first predetermined angle of incidence (ail) is in a range from 0° to 2°.

7. The light generating system (1000) according to any one of the preceding claims, wherein the optics (500) comprise one or more collimating optical elements (530,560,570), wherein the first light generating device (110) and the optics (500) are configured such that, in an operational mode of the light generating system (1000), first device light (111) escaping from the light generating system (1000) via the light exit (1090) has, upon escape from the light exit (1090), a system light full width half maximum diffusion angle (0SF) selected from the range of 0.1-3°.

8. The light generating system (1000) according to any one of the preceding claims, wherein the one or more diffusers (600) further comprise a second diffuser (620); wherein: the second diffuser (620) is a transmissive diffuser; wherein the second diffuser (620) is configured downstream of the first diffuser arrangement (601) and upstream of 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 first device light (111) directed via2024PF8007656 the second diffuser (620) in the optical path to the light exit (1090) and (b) the luminescent material light (201).

9. The light generating system (1000) according to claim 8, wherein the second diffuser (620) has a second full width half maximum diffusion angle (02) for coherent light under a second predetermined angle of incidence (ai2), wherein the second full width half maximum diffusion angle (92) is larger than the first full width half maximum diffusion angle (91).

10. The light generating system (1000) according to any one of the preceding claims 8-9, wherein the second diffuser (620) is further configured to depolarize the first device light (111) received via the first diffuser (610) into depolarized first device light (111).

11. The light generating system (1000) according to any one of the preceding claims, wherein the first light generating device (110) and the optics (500) are selected and configured such that first device light (111) emanating from the specular reflecting metallic reflector (610) has a radiance of at maximum 90 W / (cm2.sr).

12. The light generating system (1000) according to any one of the preceding claims, further comprising a second redirection element (520); wherein: the luminescent material (200) is configured in the reflective mode; the second redirection element (520) is configured in an optical path between the first redirection element (510) and the light exit (1090) and in an optical path between the second luminescent material (200) and the light exit (1090); wherein the second redirection element is configured to (a) direct first device light (111), received by the second redirection element (520) via the first redirection element (510), and (b) direct luminescent material light (201) received by the second redirection element (520), in an optical path to the light exit (1090).

13. The light generating system (1000) according to any one of the preceding claims, wherein the optics (500) are selected and configured such that the first device light (111) upon escape from the light exit (1090) has a first cross sectional area (Al) defined by the full width half maximum of the first device light (111), the luminescent material light (201) upon escape from the light exit (1090) has a second cross sectional area (A2) defined2024PF8007657 by the full width half maximum of the luminescent material light (201), and wherein either the first cross sectional area (Al) and the second cross sectional area (A2) fully overlap each other or wherein at least 80% of the larger of the cross sectional areas (A1,A2) overlaps with at least 80% of the smaller of the cross sectional areas (A1,A2).

14. The light generating system (1000) according to any one of the preceding claims, wherein: the system light (1001) comprises, in an operational mode of the light generating system (1000), (a) the first device light (111) and (b) the luminescent material light (201); the system light (1001) is white light having a correlated color temperature selected from the range of 1500-12000 K and a color rendering index of at least 65; the light generating system (1000) further comprises a control system (300) configured to control the first light generating device (110) and the second light generating device (120); the first device light (111) comprises one or more of blue light, orange light, and red light; the second device light (121) comprises one or more of violet and blue light; the luminescent material (200) at least comprises a luminescent material of the type A3BsOi2:Ce3+, 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 the first light generating device (110) comprises a first laser bank comprising a plurality of first lasers (10), and wherein the second light generating device (120) comprises a second laser bank comprising a plurality of second lasers (20).

15. A lighting device (1200) selected from the group of a lamp (1), a luminaire (2), a projector device (3), a, lighting fixture, comprising the light generating system (1000) according to any one of the preceding claims.

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