High brightness white light source comprising a blue laser bank and a blue-red laser bank

Abstract

The invention provides a light generating system (1000) comprising a first light generating arrangement (1100), a second light generating arrangement (1200), a luminescent material (200), one or more diffusers (710), and a control system (300); wherein the first light generating arrangement (1100) comprises a plurality of first light generating devices (110) configured to generate first device light (111); wherein the first light generating arrangement (1100) comprises a first laser bank comprising the plurality of first light generating devices (110); wherein the first light generating devices (110) comprise first laser diodes; and wherein the second light generating arrangement (1200) comprises a plurality of second light generating devices (120); wherein the plurality of second light generating devices (120) comprises (a) one or more primary second light generating devices (1210), configured to generate primary second device light (1211), and (b) one or more secondary second light generating devices (1220), configured to generate secondary second device light (1221); wherein the second light generating arrangement (1200) comprises a second laser bank comprising the plurality of second light generating devices (120); wherein the plurality of second light generating devices (120) comprise primary second laser diodes and secondary second laser diodes.

Description

[0001] High brightness white light source comprising a blue laser bank and a blue-red laser bank

[0002] FIELD OF THE INVENTION

[0003] The invention relates to a light generating system as well as to a lighting device comprising such light generating system.

[0004] BACKGROUND OF THE INVENTION

[0005] Light emitting devices comprising a plurality of light sources are known in the art. WO2022 / 143318, for instance, describes a light emitting device, comprising a first light source, a second light source, a dichroic mirror, a wavelength conversion apparatus, a first light path adjusting apparatus or a second light path adjusting apparatus, and a first scattering optical system. WO2022 / 143318 further states: (a) the light mixing effect of emergent light can be improved by using the first scattering optical system, (b) the color temperature of the emergent light of the light emitting device can be freely adjusted by independently adjusting the power of the first light source and the power of the second light source, (c) a laser capable of emitting light of different dominant wavelengths can be used in the second light source to improve the color rendering index of the emergent light of the light emitting device, and (d) light emitted by the first light source in the present invention is all used for exciting the wavelength conversion apparatus.

[0006] W02020 / 135300A1 discloses a light source system that includes a first light source for emitting laser light, a second light source for emitting laser light and a rotatable wavelength conversion device. The wavelength conversion device includes a substrate, a diffuser and a driving member. The wavelength conversion device further includes a reflection area and a wavelength conversion area located on the same side of the substrate and arranged in sections, and the laser light emitted from the first light source is incident on the reflection area and the wavelength conversion area in time sequence. The laser light emitted from the first light source enters the wavelength conversion region to excite and generate fluorescence, and the laser light emitted from the second light source is scattered by the diffuser and mixed with fluorescent light of the same color to emit light.

[0007] WO2023 / 126202A1 discloses a light generating system comprising a first blue laser light source, a second blue laser light source that is different from the first one, a third red laser light source, a luminescent material, and a control system. The luminescent material is configured to generate luminescent material light having a centroid wavelength within the green-orange wavelength range. The light generating system generates white light.

[0008] WO2021 / 063878 Al discloses a system with a blue laser that excites a yellow / green luminescent element. A green laser provides light that is transmitted through the yellow / green luminescent element. The light generated by the yellow / green luminescent element and the transmitted light from the green laser is combined with light from a red laser and light from a blue laser.

[0009] SUMMARY OF THE INVENTION

[0010] High brightness light sources can be used in various applications including spots, stage-lighting, headlamps, home and office lighting, and automotive lighting. For this purpose, laser-phosphor technology can be used, wherein a laser provides laser light and a remote phosphor converts laser light into converted light. A relatively straightforward way to produce white light using lasers is to use laser light in combination to generate phosphor converted light. 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, such light engine may be capable to generate only a single color point as defined by the luminescent converter. Creation of a product range providing different color points may be difficult as it may require multiple unique components to be designed, qualified, produced, and kept in stock. In other cases, e.g. in RGB LCD-based projection systems, 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. A way to combine pump light and luminescent light may be to use a polarizing beam splitter for the pump light, by which part of the light is reflected to the luminescent material and part is transmitted to a diffuser. However, in general the diffused light may to a large degree be depolarized, which may result in relatively high losses of diffused blue light at the beam combiner where it is combined with the luminescent light into white output light.

[0011] 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. According to a first aspect, the invention provides a light generating system (“system”) comprising a first light generating arrangement (“first arrangement”), a second light generating arrangement (“second arrangement”), a luminescent material, one or more diffusers. In embodiments, the system may also comprise a control system. In embodiments, the first light generating arrangement may comprise a plurality of first light generating devices configured to generate first device light. Further, in specific embodiments the first light generating arrangement may comprise a first laser bank comprising the plurality of first light generating devices. Especially, in embodiments the first light generating devices may comprise first laser diodes. Further, in embodiments the second light generating arrangement may comprise a plurality of second light generating devices. Further, in specific embodiments the plurality of second light generating devices may comprise one or more of (a) one or more primary second light generating devices, configured to generate primary second device light, and (b) one or more secondary second light generating devices, configured to generate secondary second device light. Yet, in specific embodiments the second light generating arrangement may comprise a second laser bank comprising the plurality of second light generating devices (i.e. one or more primary second light generating devices and one or more secondary second light generating devices). Especially, in embodiments the plurality of second light generating devices may comprise primary second laser diodes and / or secondary second laser diodes. Further, in embodiments the luminescent material may be configured in a light receiving relationship with the first light generating arrangement and may especially be configured to convert at least part of the first device light into luminescent material light. In embodiments, the first device light may comprise one or more of violet light and blue light. Alternatively or additionally, in embodiments the primary second device light may comprise blue light. Alternatively or additionally, in embodiments the secondary second device light may comprise one or more of green, yellow, orange, and red light. Alternatively or additionally, in embodiments the luminescent material light may comprise one or more of green, yellow, orange, and red light. Yet, in embodiments the primary second device light, the secondary second device light, and the luminescent material light may have different spectral power distributions. Further, in embodiments the one or more diffusers may be configured in a light receiving relationship with the second light generating arrangement and may be configured to convert at least part of the primary second device light and at least part of the secondary second device light into diffused primary second device light and diffused secondary second device light (respectively). Especially, in embodiments the light generating system may be configured to generate system light comprising one or more of the diffused primary second device light, the diffused secondary second device light, and the luminescent material light. Yet, in embodiments in an operational mode of the light generating system the system light may be white light comprising the diffused primary second device light, the diffused secondary second device light, and the luminescent material light. In specific embodiments, the control system may be configured to control the first light generating devices and the second light generating devices. Hence, in specific embodiments the invention provides a light generating system comprising a first light generating arrangement, a second light generating arrangement, a luminescent material, one or more diffusers, and a control system; wherein: (A) the first light generating arrangement may comprise a plurality of first light generating devices configured to generate first device light; wherein the first light generating arrangement may comprise a first laser bank comprising the plurality of first light generating devices; wherein the first light generating devices comprise first laser diodes; (B) the second light generating arrangement may comprise a plurality of second light generating devices; wherein the plurality of second light generating devices may comprise (a) one or more primary second light generating devices, configured to generate primary second device light, and (b) one or more secondary second light generating devices, configured to generate secondary second device light; wherein the second light generating arrangement may comprise a second laser bank comprising the plurality of second light generating devices; wherein the plurality of second light generating devices comprise primary second laser diodes and secondary second laser diodes; (C) the luminescent material is configured in a light receiving relationship with the first light generating arrangement and is configured to convert at least part of the first device light into luminescent material light; (D) the first device light may comprise one or more of violet light and blue light; the primary second device light may comprise blue light; the secondary second device light may comprise one or more of green, yellow, orange, and red light; the luminescent material light may comprise one or more of green, yellow, orange, and red light; and the primary second device light, the secondary second device light, and the luminescent material light have different spectral power distributions; (E) the one or more diffusers are configured in a light receiving relationship with the second light generating arrangement and are configured to convert at least part of the primary second device light and at least part of the secondary second device light into diffused primary second device light and diffused secondary second device light (respectively); (F) the light generating system is configured to generate system light comprising one or more of the diffused primary second device light, the diffused secondary second device light, and the luminescent material light; wherein in an operational mode of the light generating system the system light is white light comprising the diffused primary second device light, the diffused secondary second device light, and the luminescent material light; and (G) the control system is configured to control the first light generating devices and the second light generating devices.

[0012] With such system high intensity and color tunability is possible. Also correlated color temperature (CCT) control may be possible. Further, a high color rendering index (CRI) may be possible. The architecture can be relatively simple. Further, thermal management may be possible with the proposed system.

[0013] As indicated above, the light generating system may comprise a first light generating arrangement, a second light generating arrangement, a luminescent material, one or more diffusers, and optionally a control system.

[0014] Each light generating arrangement may comprise a plurality of light generating devices. Especially, the light generating devices may be selected from light emitting diodes (LEDs), laser diodes, and superluminescent diodes. Hence, the light generating devices may comprise solid state light sources. Especially, the light generating devices comprise laser diodes. Especially, each arrangement may comprise a (respective) laser bank, wherein a first laser bank may comprise the first light generating devices, and wherein a s second laser bank may comprise the second light generating devices. Here below, some aspects of the light generating arrangements, light generating devices, (solid state) light sources, and laser banks are described.

[0015] Each light generating device may comprise a (solid state) light source.

[0016] Especially, in embodiments, the one or more light generating devices may comprise light sources selected from a laser diode, a stacked multi -junction light emitting diode, and a superluminescent diode. Embodiments of light generating devices and (solid state) light sources are described below in general, and may (individually) apply to the one or more light generating devices. Hence, the light generating system may comprise one or more light generating devices. A light generating device may especially be configured to generate device light. Especially, the light generating device may comprise a light source. The light source may especially configured to generate light source light. In embodiments, the device light may essentially consist of the light source light. In other embodiments, the device light may essentially consist of converted light source light. In yet other embodiments, the device light may comprise (unconverted) light source light and converted light source light. Light source light may be converted with a luminescent material into luminescent material light and / or with an upconverter into upconverted light (see also below). The term “light generating device” may also refer to a plurality of light generating devices which may provide device light having essentially the same spectral power distributions. In (other) specific embodiments, the term “light generating device” may also refer to a plurality of light generating devices which may provide device light having different spectral power distributions.

[0017] 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 emissive diode). In a specific embodiment, the light source comprises a solid state LED light source (such as an LED or laser diode (or “diode laser”)). The term “light source” may also relate to a plurality of light sources, such as 2-2000 (solid state) LED light sources. Hence, the term LED may also refer to a plurality of LEDs. 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. The term “light source” may also refer to a chip scaled package (CSP). A CSP may comprise a single solid state die with provided thereon a luminescent material comprising layer. The term “light source” may also refer to a midpower package. A midpower package may comprise one or more solid state die(s). The die(s) may be covered by a luminescent material comprising layer. The die dimensions may be equal to or smaller than 2 mm, such as in the range of e.g. 0.2-2 mm. Hence, in embodiments the light source comprises a solid state light source. Further, in specific embodiments, the light source comprises a chip scale packaged LED. Herein, the term “light source” may also especially refer to a small solid state light source, such as having a mini size or micro size. For instance, the light sources may comprise one or more of mini LEDs and micro LEDs. Especially, in embodiment the light sources comprise micro LEDs or “microLEDs” or “pLEDs”. Herein, the term mini size or mini LED especially indicates to solid state light sources having dimensions, such as die dimension, especially length and width, selected from the range of 100 pm - 1 mm. Herein, the term p size or micro LED especially indicates to solid state light sources having dimensions, such as die dimension, especially length and width, selected from the range of 100 pm and smaller. 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.

[0018] 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.

[0019] A position where system light escapes from the light generating system may also be indicated as light exit. This may be a light transmissive window or an opening (in the system). The light transmissive window may in embodiments be provided by an optical component.

[0020] The term “light source” may refer to a semiconductor light-emitting device, such as a light emitting diode (LEDs), a laser diode, a resonant cavity light emitting diode (RCLED), a vertical cavity laser diode (VCSELs), an edge emitting laser (EEL), a photonic crystal surface emitting laser (PCSEL), a vertical external cavity surface emitting laser (VECSEL), 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). 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). The term LED may also refer to a plurality of LEDs.

[0021] In embodiments, the light source may be configured to provide primary radiation, which is used as such, such as e.g. a blue light source, like a blue LED, or a green light source, such as a green LED, and a red light source, such as a red LED. Such LEDs, which may not comprise a luminescent material (“phosphor”) may be indicated as direct color LEDs. 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. 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.

[0022] 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.

[0023] The term “light source” may (thus) refer to a light generating element as such, like e.g. a solid state light source, or e.g. to a package of the light generating element, such as a solid state light source, and one or more of a luminescent material comprising element and (other) optics, like a lens, a collimator. A light converter element (“converter element” or “converter”) may comprise a luminescent material comprising element. For instance, a solid state light source as such, like a blue LED, is a light source. A combination of a solid state light source (as light generating element) and a light converter element, such as a blue LED and a light converter element, optically coupled to the solid state light source, may also be a light source (but may also be indicated as light generating device). Hence, a white LED is a light source (but may e.g. also be indicated as (white) light generating device). The term “light source” herein may also refer to a light source comprising a solid state light source, such as an LED, a stacked multi -junction light emitting diode, a laser diode or a superluminescent diode. 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. 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.

[0024] 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.

[0025] 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.

[0026] The term “laser light source” especially refers to a laser. Such laser may especially be configured to generate laser light source light having one or more wavelengths in the UV, visible, or infrared, especially having a wavelength selected from the spectral wavelength range of 200-2000 nm, such as 300-1500 nm. The term “laser” especially refers to a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. Especially, in embodiments the term “laser” may refer to a solid-state laser. In specific embodiments, the terms “laser” or “laser light source”, or similar terms, refer to a laser diode (or diode laser). Hence, in embodiments the light source comprises a laser light source. In embodiments, the terms “laser” or “solid state laser” or “solid state material laser” may refer to one or more of cerium doped lithium strontium (or calcium) aluminum fluoride (Ce:LiSAF, Ce:LiCAF), chromium doped chrysoberyl (alexandrite) laser, chromium ZnSe (CrZnSe) laser, divalent samarium doped calcium fluoride (Sm:CaF2) laser, Er: YAG laser, erbium doped and erbium-ytterbium codoped glass lasers, F-Center laser, holmium YAG (Ho:YAG) laser, Nd:YAG laser, NdCrYAG laser, neodymium doped yttrium calcium oxoborate Nd:YCa4O(BO3)3 or Nd:YCOB, neodymium doped yttrium orthovanadate (Nd: YVO4) laser, neodymium glass (Nd:glass) laser, neodymium YLF (Nd:YLF) solid-state laser, promethium 147 doped phosphate glass (147Pm3+:glass) solid-state laser, ruby laser (AhO3:Cr3+), thulium YAG (Tm:YAG) laser, titanium sapphire (Ti:sapphire; AhChYi3) laser, trival ent uranium doped calcium fluoride (U:CaF2) solid-state laser, Ytterbium doped glass laser (rod, plate / chip, and fiber), Ytterbium YAG (Yb:YAG) laser, Yb2O3 (glass or ceramics) laser, etc.

[0027] For instance, including second and third harmonic generation embodiments, the light source may comprise one or more of an F center laser, an yttrium orthovanadate (Nd:YVO4) laser, a promethium 147 doped phosphate glass (147Pm3+:glass), and a titanium sapphire (Ti:sapphire; AhChYi3) laser. For instance, considering second and third harmonic generation, such light sources may be used to generated blue light.

[0028] 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.

[0029] A laser may be combined with an upconverter in order to arrive at shorter (laser) wavelengths. For instance, with some (trival ent) rare earth ions upconversion may be obtained or with non-linear crystals upconversion can be obtained. Alternatively, a laser can be combined with a downconverter, such as a dye laser, to arrive at longer (laser) wavelengths.

[0030] As can be derived from the below, the term “laser light source” may also refer to a plurality of (different or identical) laser light sources. In specific embodiments, the term “laser light source” may refer to a plurality N of (identical) laser light sources. In embodiments, N=2, or more. In specific embodiments, N may be at least 5, such as especially at least 8. In this way, a higher brightness may be obtained.

[0031] The laser light source may be configured to generate laser light source light (or “laser light”). The light source light may essentially consist of the laser light source light. The light source light may also comprise laser light source light of two or more (different or identical) laser light sources. For instance, the laser light source light of two or more (different or identical) laser light sources may be coupled into a light guide, to provide a single beam of light comprising the laser light source light of the two or more (different or identical) laser light sources. In specific embodiments, the light source light is thus especially collimated light source light. In yet further embodiments, the light source light is especially (collimated) laser light source light. The laser light source light may in embodiments comprise one or more bands, having band widths as known for lasers. In specific embodiments, the band(s) may be relatively sharp line(s), such as having full width half maximum (FWHM) in the range of less than 20 nm at RT, such as equal to or less than 10 nm. Hence, the light source light has a spectral power distribution (intensity on an energy scale as function of the wavelength) which may comprise one or more (narrow) bands.

[0032] The beams (of light source light) may be focused or collimated beams of (laser) light source light. The term “focused” may especially refer to converging to a small spot. This small spot may be at the discrete converter region, or (slightly) upstream thereof or (slightly) downstream thereof. Especially, focusing and / or collimation may be such that the cross-sectional shape (perpendicular to the optical axis) of the beam at the discrete converter region (at the side face) is essentially not larger than the cross-section shape (perpendicular to the optical axis) of the discrete converter region (where the light source light irradiates the discrete converter region). Focusing may be executed with one or more optics, like (focusing) lenses. Especially, two lenses may be applied to focus the laser light source light. Collimation may be executed with one or more (other) optics, like collimation elements, such as lenses and / or parabolic mirrors. In embodiments, the beam of (laser) light source light may be relatively highly collimated, such as in embodiments <2° (FWHM), more especially <1° (FWHM), most especially <0.5° (FWHM). Hence, <2° (FWHM) may be considered (highly) collimated light source light. Optics may be used to provide (high) collimation (see also above).

[0033] The term “solid state material laser”, and similar terms, may refer to a solid state laser like based on a crystalline or glass body dopes with ions, like transition metal ions and / or lanthanide ions, to a fiber laser, to a photonic crystal laser, to a semiconductor laser, such as e.g. a vertical cavity surface-emitting laser (VCSEL), etc. The term “solid state light source”, and similar terms, may especially refer to semiconductor light sources, such as a light emitting diode (LED), a laser diode, or a superluminescent diode. Instead of the term “solid state light source” also the term “semiconductor-based light source” may be applied. Hence, the term “semiconductor-based light source” may e.g. refer to one or more of a light emitting diode (LED), a laser diode, and a superluminescent diode. Hence, the light generating device may comprise one or more of a light emitting diode (LED), a laser diode, and a superluminescent diode.

[0034] A light-emitting diode (LED) is especially a semiconductor light source that emits light when current flows through it. Electrons in the semiconductor may recombine with electron holes, releasing energy in the form of photons. The color of the light (corresponding to the energy of the photons) may be determined by the energy required for electrons to cross the band gap of the semiconductor.

[0035] 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.

[0036] 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. The 2D array may e.g. comprise at least 8 laser diodes.

[0037] Hence, in embodiments the first light generating arrangement may comprise a plurality of first light generating devices configured to generate first device light. Especially, in embodiments the first light generating arrangement may comprise a first laser bank comprising the plurality of first light generating devices. More especially, the first light generating devices may comprise first laser diodes. In embodiments, the first device light may comprise blue light and / or violet light. However, in other embodiments the first device light may comprise UV radiation. Therefore, in embodiments the first device light may comprise one or more of UV, violet and blue radiation, more especially one or more of violet radiation and blue radiation (see further also below about colors). The laser bank may comprise a 2D arrangement with xl*yl first laser diodes, wherein xl>2, especially xl>4, and wherein yl>2, especially yl>4.

[0038] Yet, in embodiments the second light generating arrangement comprises a plurality of second light generating devices. Especially, in embodiments the plurality of second light generating devices may comprise (a) one or more primary second light generating devices, configured to generate primary second device light, and (b) one or more secondary second light generating devices, configured to generate secondary second device light. Especially, in embodiments the second light generating arrangement may comprise a second laser bank comprising the plurality of second light generating devices. More especially, the plurality of second light generating devices may comprise primary second laser diodes and secondary second laser diodes. In embodiments, the primary second device light may comprise blue light. However, the secondary second device light may comprise one or of green light, yellow light, orange light, and red light (see further also below about colors). The laser bank may comprise a 2D arrangement with x2*y2 second laser diodes, wherein x2>2, especially x2>4, and wherein y2>2, especially y2>4; see further also below.

[0039] In embodiments, the plurality of first light generating devices may comprises at least 4 or at least 8 or at least 12 first laser diodes. In embodiments, the plurality of second light generating devices may comprises at least 4 or at least 8 or at least 12 second laser diodes. In embodiments, the primary second laser diodes may comprise at least 3 or at least 6 or at least 9 laser diodes. In embodiments, the secondary second laser diodes may comprise at least 3 or at least 6 or at least 9 laser diodes.

[0040] As indicated above, the system may comprise a 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” 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 downconversion. In specific embodiments, however the second radiation has a spectral power distribution with intensity at smaller wavelengths than the first radiation, which is the case in the so-called up-conversion. 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 (Xex>Xem). 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.

[0041] 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.

[0042] 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 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.

[0043] In embodiments, the luminescent material (thus) comprises A3B5O12 wherein in specific embodiments at maximum 10% of B-0 may be replaced by Si-N.

[0044] In specific embodiments the luminescent material comprises (YxiA’X2CeX3)3(AlyiB’y2)5Oi2, wherein xl+x2+x3=l, wherein x3>0, wherein 0<x2+x3<0.2, wherein yl+y2=l, wherein especially 0<y2<0.2, wherein A’ comprises one or more elements selected from the group consisting of lanthanides, and wherein B’ comprises one or more elements selected from the group consisting of Ga, In and Sc. In embodiments, x3 is selected from the range of 0.001-0.1. In the present invention, especially xl>0, such as >0.2, like at least 0.8. Garnets with Y may provide suitable spectral power distributions.

[0045] In specific embodiments at maximum 10% of B-0 may be replaced by Si-N. Here, B in B-0 refers to one or more of Al, Ga, In and Sc (and O refers to oxygen); in specific embodiments B-0 may refer to Al-O. As indicated above, in specific embodiments x3 may be selected from the range of 0.001-0.04. Especially, such luminescent materials may have a suitable spectral distribution (see however below), have a relatively high efficiency, have a relatively high thermal stability, and allow a high CRI (optionally in combination with (the) light of other sources of light as described herein). Hence, in specific embodiments A may be selected from the group consisting of Lu and Gd. Alternatively or additionally, B may comprise Ga. Hence, in embodiments the luminescent material comprises (Yxi(Lu,Gd)X2CeX3)3(AlyiGay2)5Oi2, wherein Lu and / or Gd may be available. Even more especially, x3 is selected from the range of 0.001-0.1, wherein 0<x2+x3<0.1, and wherein 0<y2<0.1. Further, in specific embodiments, at maximum 1% of B-0 may be replaced by Si- N. Here, the percentage refers to moles (as known in the art); see e.g. also EP3149108. In yet further specific embodiments, the luminescent material comprises (YxiCeX3)3A150i2, wherein xl+x3=l, and wherein 0<x3<0.2, such as 0.001-0.1.

[0046] In specific embodiments, the light generating device may only include luminescent materials selected from the type of cerium comprising garnets. In even further specific embodiments, the light generating device includes a single type of luminescent materials, such as (YxiA’X2CeX3)3(AlyiB’y2)5Oi2. Hence, in specific embodiments the light generating device comprises luminescent material, wherein at least 85 weight%, even more especially at least about 90 wt.%, such as yet even more especially at least about 95 weight % of the luminescent material comprises (¥xiA’X2CeX3)3(AlyiB’y2)5Oi2. Here, wherein A’ comprises one or more elements selected from the group consisting of lanthanides, and wherein B’ comprises one or more elements selected from the group consisting of Ga, In and Sc, wherein xl+x2+x3=l, wherein x3>0, wherein 0<x2+x3<0.2, wherein yl+y2=l, wherein 0<y2<0.2. Especially, x3 is selected from the range of 0.001-0.1. Note that in embodiments x2=0. Alternatively or additionally, in embodiments y2=0.

[0047] In specific embodiments, A may especially comprise at least Y, and B may especially comprise at least Al.

[0048] Alternatively or additionally, the luminescent material may comprise a luminescent material of the type AsSieNiuCe3, wherein A comprises one or more of Y, La, Gd, Tb and Lu, such as in embodiments one or more of La and Y.

[0049] In embodiments, the luminescent material may alternatively or additionally comprise one or more of MS:Eu2+and / or LSisNs Eu2and / or MAlSiNrEu2and / 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 be (Cao.98Euo.o2)AlSiN3. Divalent europium will in general replace divalent cations, such as the above divalent alkaline earth cations, especially Ca, Sr, or Ba. The material (Ba,Sr,Ca)S:Eu can also be indicated as MS:Eu, wherein M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca); especially, M comprises in this compound calcium or strontium, or calcium and strontium, more especially calcium. Here, Eu is introduced and replaces at least part of M (i.e. one or more of Ba, Sr, and Ca). Further, the material (Ba,Sr,Ca)2SisN8:Eu can also be indicated as NESis Eu, wherein M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca); especially, M comprises in this compound Sr and / or Ba. In a further specific embodiment, M consists of Sr and / or Ba (not taking into account the presence of Eu), especially 50 to 100%, more especially 50 to 90% Ba and 50 to 0%, especially 50 to 10% Sr, such as Bai.sSro.sSis Eu (i.e. 75 % Ba; 25% Sr). Here, Eu is 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.

[0050] 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.

[0051] 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).

[0052] 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).

[0053] 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).

[0054] 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.

[0055] Blue luminescent materials may comprise YSO (Y2SiOs:Ce3+), or similar compounds, or BAM (BaMgAlioOi?:Eu2+), or similar compounds.

[0056] The term “luminescent material” herein especially relates to inorganic luminescent materials. Alternatively or additionally, also other luminescent materials may be applied. For instance quantum dots and / or organic dyes may be applied and may optionally be embedded in transmissive matrices like e.g. polymers, like PMMA, or polysiloxanes, etc. etc.. Quantum dots are small crystals of semiconducting material generally having a width or diameter of only a few nanometers. When excited by incident light, a quantum dot emits light of a color determined by the size and material of the crystal. Light of a particular color can therefore be produced by adapting the size of the dots. Most known quantum dots with emission in the visible range are based on cadmium selenide (CdSe) with a shell such as cadmium sulfide (CdS) and zinc sulfide (ZnS). Cadmium free quantum dots such as indium phosphide (InP), and copper indium sulfide (CuInS?) and / or silver indium sulfide (AglnS?) can also be used. Quantum dots show very narrow emission band and thus they show saturated colors. Furthermore the emission color can easily be tuned by adapting the size of the quantum dots. Any type of quantum dot known in the art may be used in the present invention. However, it may be preferred for reasons of environmental safety and concern to use cadmium-free quantum dots or at least quantum dots having a very low cadmium content. Instead of quantum dots or in addition to quantum dots, also other quantum confinement structures may be used. The term “quantum confinement structures” should, in the context of the present application, be understood as e.g. quantum wells, quantum dots, quantum rods, tripods, tetrapods, or nanowires, etcetera. Organic phosphors can be used as well. Examples of suitable organic phosphor materials are organic luminescent materials based on perylene derivatives, for example compounds sold under the name Lumogen® by BASF. Examples of suitable compounds include, but are not limited to, Lumogen® Red F305, Lumogen® Orange F240, Lumogen® Yellow F083, and Lumogen® F170.

[0057] 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). 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.

[0058] In embodiments, the luminescent material may be configured in a light receiving relationship with the first light generating arrangement and may be configured to convert at least part of the first device light into luminescent material light.

[0059] In embodiments, the first device light comprises one or more of violet light and blue light. Alternatively or additionally, the primary second device light may comprise blue light. Yet alternatively or additionally, the secondary second device light may comprise one or more of green, yellow, orange, and red light. Further alternatively or additionally, the luminescent material light may comprise one or more of green, yellow, orange, and red light. Especially, in embodiments the first device light may comprise blue light, the primary second device light may comprise blue light, and the secondary second device light may comprises red light.

[0060] The terms “visible”, “visible light” or “visible emission” and similar terms refer to light having one or more wavelengths in the range of about 380-780 nm. Herein, UV may especially refer to a wavelength selected from the range of 190-380 nm, such as 200-380 nm. The terms “light” and “radiation” are herein interchangeably used, unless clear from the context that the term “light” only refers to visible light. The terms “light” and “radiation” may thus refer to UV radiation, visible light, and IR radiation. In specific embodiments, especially for lighting applications, the terms “light” and “radiation” refer to (at least) visible light. 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 620-750 nm. In specific embodiments, the red light may have a centroid wavelength in the 620-750 nm range. The terms “cyan light” or “cyan emission”, and similar terms, especially relate to light having a wavelength in the range of about 490-520 nm. In specific embodiments, the cyan light may have a centroid wavelength in the 490-520 nm range. The terms “amber light” or “amber emission”, and similar terms, may especially relate to light having a wavelength in the range of about 585-605 nm, such as about 590-600 nm. In specific embodiments, the amber light may have a centroid wavelength in the 585-605 nm range. The phrase “light having one or more wavelengths in a wavelength range” and similar phrases may especially indicate that the indicated light (or radiation) has a spectral power distribution with at least intensity or intensities at these one or more wavelengths in the indicate wavelength range. For instance, a blue emitting solid state light source will have a spectral power distribution with intensities at one or more wavelengths in the 440-495 nm wavelength range.

[0061] The spectral power distributions of the first device light and the primary second device light may essentially be the same. In specific embodiments, the first light generating devices and the primary second light generating devices are from the same bin. In other embodiments, however, the spectral power distributions of the first device light and the primary second device light may be the same. Hence, in embodiments the first device light and the primary second device light may have the same color (and in other embodiments they may have different colors).

[0062] In specific embodiments, colors, or color points of a first type of light and a second type of light may be different when the respective color points of the first type of light and the second type of light differ with at least 0.01 for u’ and / or with at least 0.01 for v’, even more especially at least 0.02 for u’ and / or with at least 0.02 for v’. In yet more specific embodiments, the respective color points of first type of light and the second type of light may differ with at least 0.03 for u’ and / or with at least 0.03 for v’. Here, u’ and v’ are color coordinates of the light in the CIE 1976 UCS (uniform chromaticity scale) diagram. Spectral power distributions of different sources of light having centroid wavelengths differing least 10 nm, such as at least 20 nm, or even at least 30 nm may be considered different spectral power distributions, e.g. different colors. In general, the differences in centroid wavelengths will not be larger than about 400 nm, such as not more than 350 nm. In other specific embodiments, colors or color points of a first type of light and a second type of light may be essentially the same when the respective color points of the first type of light and the second type of light differ with at maximum 0.03 for u’ and / or with at maximum 0.03 for v’, even more especially at maximum 0.02 for u’ and / or with at maximum 0.02 for v’. In yet more specific embodiments, the respective color points of first type of light and the second type of light may differ with at maximum 0.01 for u’ and / or with at maximum 0.01 for v’. Here, u’ and v’ are color coordinate of the light in the CIE 1976 UCS (uniform chromaticity scale) diagram. The color points indicated with u’,v’ may especially refer to the CIE 1976 color points (see ISO CIE 11664-5: Colorimetry - Part5: CIE 1976 L*u*v* color space and u', v' uniform chromaticity scale diagram).

[0063] Further, in embodiments the primary second device light, the secondary second device light, and the luminescent material light may have different spectral power distributions. Especially, in embodiments the primary second device light, the secondary second device light, and the luminescent material light may have different colors. For instance, the primary second device light may be blue, the secondary second device light may be red, and the luminescent material may be green or yellow. However, other embodiments may also be possible.

[0064] Further, the term “first light generating device” may in embodiments refer to a plurality of first light generating devices which may provide first device light having essentially the same spectral power distributions, but may in other embodiments refer to a plurality of first light generating devices comprising at least two first light generating devices which may provide first device light having different spectral power distributions. Likewise, the term “primary second light generating device” may in embodiments refer to a plurality of primary second light generating devices which may provide primary second device light having essentially the same spectral power distributions, but may in other embodiments refer to a plurality of primary second light generating devices comprising at least two primary second light generating devices which may provide primary second device light having different spectral power distributions. Yet, likewise, the term “secondary second light generating device” may in embodiments refer to a plurality of secondary second light generating devices which may provide secondary second device light having essentially the same spectral power distributions, but may in other embodiments refer to a plurality of secondary second light generating devices comprising at least two secondary second light generating devices which may provide secondary second device light having different spectral power distributions.

[0065] Whether or not the luminescent material is configured in the reflective more or transmissive mode, the luminescent material light generated may substantially be diffuse (luminescent material) light. The first device light used to irradiate the luminescent material may not be fully absorbed, e.g. due to reflection in the reflective mode or transmission in the transmissive mode. Especially, such unconverted first device light may be filtered out, e.g. with a dichroic mirror, see also below. However, the luminescent material and the first device light may also be chosen such that essentially all first device light is absorbed by the luminescent material, i.e. “full conversion”. Therefore, especially in embodiments, essentially no first device light may end up in the system light (for instance less than 1% of the spectral power within the 380-780 nm wavelength range may be provided by the first device light, even more especially less than 0.1%).

[0066] Hence, in embodiments, the luminescent material may not be configured in a light receiving relationship with the second light generating arrangement and may not be configured to convert at least part of the second device light into luminescent material light. The second device light, i.e. the primary second device light and secondary second device light may essentially bypass the luminescent material.

[0067] However, the second device light may be relatively collimated light. It appears, however, desirable to apply diffuse second device light, especially at high powers (which is possible with lasers, like laser diodes). Hence, a diffuser may be applied to diffuse the second device light. Hence, a diffuser may be used to decrease the influence the angular distribution of the light (especially due to scattering). In embodiments, the diffuser may increase divergence of (a beam of) light. Therefore, in embodiments the one or more diffusers may be configured in a light receiving relationship with the second light generating arrangement and may be configured to convert at least part of the primary second device light and at least part of the secondary second device light into diffused primary second device light and diffused secondary second device light (respectively). In embodiments, essentially no second device light ends up in the system light without being diffused by one or more diffusers. In embodiments, at least one of the one or more diffusers may be configured in the transmissive mode and / or at least one of the one or more diffusers may be configured in the reflective mode. Especially, each of the one of the one or more diffusers may be configured in the transmissive mode or each of the one of the one or more diffusers may be configured in the reflective mode. In more specific embodiments, each of the one of the one or more diffusers may be configured in the reflective mode.

[0068] Hence, one or more of the following may apply: (a) the one or more diffusers may be configured in a transmissive mode, and (b) the luminescent material may be configured in a transmissive mode. See further also below. Especially, however, one or more of the following may apply: (a) the one or more diffusers may be configured in a reflective mode, and (b) the luminescent material may be configured in a reflective mode. More especially both are in the reflective mode. See further also below.

[0069] Further, in embodiments the light generating system may be configured to generate system light comprising one or more of the diffused primary second device light, the diffused secondary second device light, and the luminescent material light. In specific embodiments, this may be white light. In other embodiments, this may be colored white. More especially, in embodiments in an operational mode of the light generating system the system light may be white light comprising the diffused primary second device light, the diffused secondary second device light, and the luminescent material light. This does not exclude the optional availability of other operational modes of the light generating system wherein the system light may be colored light. Hence, in another operational mode the system light may be colored light.

[0070] Further, in embodiment a spectral power distribution of the system light may be controllable. Therefore, in embodiments the (optional) control system may be configured to control the first light generating devices and the second light generating devices. In specific embodiments, the control system may be configured to control one or more of a color point, correlated color temperature, and color rendering index of the system light. Further, in embodiments the control system may be configured to individually control (a) one or more primary second light generating devices and (b) one or more secondary second light generating devices. Yet, in embodiments the control system may be configured to individually control (a) one or more first light generating devise, (b) one or more primary second light generating devices, and (c) one or more secondary second light generating devices. For instance, when increasing the power of the first light generating devices relative to the primary second light generating devices, the CCT of the white system light may decrease, whereas when increasing the power of the primary second light generating devices relative to the first light generating devices, the CCT of the white system light may increase. Further, when increasing the power of the secondary second light generating devices relative to the primary second light generating devices, the CCT of the white system light may decrease. Further, by controlling the power of the secondary second light generating devices the CRI may (further) be controlled.

[0071] The term “white light”, and similar terms, herein, is known to the person skilled in the art. It may especially relate to light having a correlated color temperature (CCT) between about 1800 K and 20000 K, such as between 2000 and 20000 K, especially 2700- 20000 K, for general lighting especially in the range of about 2000-7000 K, such as in the range of 2700 K and 6500 K. In embodiments, e.g. for backlighting purposes, or for other purposes, the correlated color temperature (CCT) may especially be in the range of about 7000 K and 20000 K. Yet further, in embodiments the correlated color temperature (CCT) is especially within about 15 SDCM (standard deviation of color matching) from the BBL (black body locus), especially within about 10 SDCM from the BBL, even more especially within about 5 SDCM from the BBL. In specific embodiments, the correlated color temperature (CCT) may be selected from the range of 6000-12000 K, like selected from the range of 7000-12000 K, like at least 8000 K. Yet further, in embodiments the correlated color temperature (CCT) may be selected from the range of 6000-12000 K, like selected from the range of 7000-12000 K, in combination with a CRI of at least 70.

[0072] 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.

[0073] 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. 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.

[0074] 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.

[0075] 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).

[0076] 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.

[0077] The second light generating arrangement may thus provide primary second device light and secondary second device light. In embodiments, the primary second device light and the secondary second device light may be diffused by the same diffuser. This may be advantageous in view of complexity reduction. Such diffuser may in embodiments be a polarization maintaining diffuser. However, in other embodiments the primary second device light and the secondary second device light may be diffused by different diffusers. This may improve the efficiency, especially when polarization maintain diffusers are applied (in combination with a polarization changing element; see also below). To have the primary second device light and the secondary second device light diffused by different diffuser, the primary second device light and the secondary second device light may be separated via a dichroic beam splitter or by a polarizing beam splitter (with in the latter case assuming that the primary second device light and the secondary second device light have different polarizations).

[0078] It appears that an efficient and / or good solution to provide diffused (laser) light is to apply a polarization maintaining diffuser, in the reflective mode, in combination with a polarization changing element.

[0079] Hence, the reflective diffuser element may in embodiments be configured to reflect and diffuse at least part of linearly polarized device light received by the diffuser element while especially maintaining at least part of the direction of linearly polarized of device light. Hence, the diffused device light generated by (and propagating from) the diffuser element may have substantially the same, such as exactly the same, direction of polarization as the linearly polarized device light incident on the diffuser element. However, in the case of elliptically polarized light, the reflective diffuser element may in embodiments be configured to reflect and diffuse at least part of the device light received by the diffuser element while especially changing a direction of elliptically polarized device light. Hence, the diffused device light generated by (and propagating from) the diffuser element may at least still partially be elliptically polarized, but having a different direction from the elliptically polarized device light incident on the diffuser element. Especially, the diffuser element may comprise a specular metal reflector comprising a diffuser. The diffuser element may also comprise a diffusers with a metallic coating.

[0080] Especially, the polarization changing element may be configured to change s- polarized light or p-polarized light to elliptically (especially circularly) polarized light having a first handedness (e.g. right-handed or left-handed polarization). The diffuser element may subsequently, in embodiments, change the direction of the circularly polarized light, but the elliptically (especially circularly) polarized light may essentially stay circularly polarized light, but now having a second handedness (e.g. left-handed or right-handed polarization). At least part of the diffused light, having circular polarization, will subsequently propagate from the diffuser element (back) to the polarization changing element, where it will be converted to (diffused) p-polarized light and / or (diffused) s-polarized light, respectively. Therefore, in some embodiments, the polarization changing element may comprise a X / 4 waveplate; wherein the polarization changing element is especially configured in an optical path of the device light between the central optics and the diffuser element. In this way, p-polarized light can be converted in diffused s-polarized light, and s-polarized light can be converted in diffused p-polarized light. Hence, in specific embodiments, the polarization changing element comprises a X / 4 waveplate. Especially, the polarization changing element may be an element that induces a 90° phase shift between the two orthogonal linear polarization components (s and p) of the light. The most common way is to use birefringent material (birefringent rotators), such as a quarter- wave plate. An alternative may be to use the Faraday effect, in which case the phase shift is caused by an applied magnetic field (Faraday rotators). Another alternative may be to use any component or set of components resulting in an up to 180° relative phase shift of one polarization versus the other polarization. In embodiments, such phase shift may be the result of any one of birefringent, electro-optical, thermo-optical, magneto-optical or any other principle known in the art. Hence, the device light may first pass the polarization changing element, whereby the polarization of the device light is changed, then at the polarization maintaining diffuser the device light is diffused, but polarization may essentially be maintained, and subsequently the diffused device light may pass again the polarization changing element, whereby again the polarization is changed. In this way, relatively collimated light having a s or p polarization may be converted in to diffused light having p or s polarization.

[0081] Hence, in embodiments the invention provides one or more diffuser sets, wherein each diffuser set comprises a diffuser arrangement and a first polarizing beam splitter. The former element may be applied to convert polarized (collimated) (laser) light into polarized diffused (laser) light, having a polarization different from the polarized (collimated) (laser) directed to the diffuser arrangement. The latter element may be configured to direct polarized (collimated) (laser) light from a first direction to the diffuser arrangement and to directed polarized diffused (laser) light, propagating away from the diffuser arrangement to a second direction, different from the first direction.

[0082] In embodiments, the diffuser arrangement may comprise (a) one of the one or more diffusers, wherein the (one) diffuser may comprise a polarization maintaining diffusor, and (b) a polarization changing element configured in an optical path between the second light generating arrangement and the polarization maintaining diffusor. Especially, as indicated above, the polarization changing element may be (a) configured to change s- polarized light or p-polarized light propagating through the a polarization changing element to the polarization maintaining diffusor diffuser into elliptically polarized light having a first handedness; wherein the polarization maintaining diffusor is configured to change at least part of the elliptically polarized light having the first handedness received by the polarization maintaining diffusor into (diffused) elliptically polarized light having the second handedness, and may be (b) configured to change at least part of the (diffused) elliptically polarized light having the second handedness propagating through the polarization changing element in a direction of a light exit of the light generating system (via the first polarizing beam splitter) into (diffused) p-polarized light and / or (diffused s-polarized light, respectively).

[0083] Yet, in embodiment the first polarizing beam splitter may be configured to reflect at least part of one or more of the primary second device light and the secondary second device light having a first polarization, and to transmit at least part of one or more of the primary second device light and the secondary second device light having a second polarization, different from the first polarization. Especially, the first polarizing beam splitter may be configured in an optical path between the second light generating arrangement and the diffuser arrangement. Further, especially the first polarizing beam splitter may (also) be configured in an optical path between the diffuser arrangement and the light exit of the light generating system).

[0084] As indicated above, the primary second device light and secondary second device light may be separated on the bases of a difference in polarization or on the basis of the (inherent) difference in spectral power distribution. A combination may also be possible. The (former) two options are shortly discussed below.

[0085] In embodiments, the one or more primary second light generating devices may be configured to generate primary second device light having a first polarization, and the one or more secondary second light generating devices may be configured to generate secondary second device light with a second polarization, different from the first polarization. For instance, the primary second device light may have p polarization and secondary second device light may have s polarization, or the primary second device light may have s polarization and secondary second device light may have p polarization. Especially, the light generating system may further comprise a second polarizing beam splitter configured to reflect at least part of the primary second device light and transmit at least part of the secondary second device light, or configured to transmit at least part of the primary second device light and reflect at least part of the secondary second device light. Further, the light generating system may be configured such that in dependence of the polarization of the second device light (1211,1221), at least part of the second device light (1211,1221) propagates from the second polarizing beam splitter to a first diffuser set (7710’) or to a second diffuser set (7710”). For instance, primary second device light (comprising s- polarization or p-polarization) may propagate to the first diffuser set and secondary second device light (comprising p-polarization or s-polarization) may propagate to the second diffuser set, or the other way around. Further, the respective first polarizing beam splitters may be configured such that the diffused primary second device light and the diffused secondary second device light, optionally in combination with other optics, follow at some point essentially the same optical path to a light exit. In this way, s-polarized primary second device light may be converted in to diffused p-polarized primary second device light, and p- polarized secondary second device light may be converted in to diffused s-polarized secondary second device light. Or, in other embodiments p-polarized primary second device light may be converted in to diffused s-polarized primary second device light, and s-polarized secondary second device light may be converted in to diffused p-polarized secondary second device light. In this way, the respective polarization changing element may be optimized for the primary second device light and the secondary second device light, respectively.

[0086] Alternatively (or additionally), in embodiments the light generating system may further comprise a first dichroic beam splitter configured to reflect at least part of the primary second device light and transmit at least part of the secondary second device light, or configured to transmit at least part of the primary second device light and reflect at least part of the secondary second device light. Yet, in embodiments the light generating system may also be configured such that in dependence of a spectral power distribution of the second device light (1211,1221), at least part of the second device light (1211,1221) propagates from the first dichroic beam splitter to a first diffuser set (7710’) or to a second diffuser set (7710”). Likewise, the respective first polarizing beam splitters may be configured such that the diffused primary second device light and the diffused secondary second device light, optionally in combination with other optics, follow at some point essentially the same optical path to a light exit. In this way, blue primary second device light may be converted in to diffused blue primary second device light, and e.g. red secondary second device light may be converted in to diffused red secondary second device light. Also in this way, the respective polarization changing element may be optimized for the primary second device light and the secondary second device light, respectively.

[0087] In embodiments, the polarization changing element may comprise a % waveplate for one or more wavelengths of the second device light (1211,1221). In embodiments, when both the primary second device light and the secondary second device light are received by the same polarization changing element, the polarization changing element may be selected such that both the primary second device light and the secondary second device light are at least partly changed in polarization. However, when a first polarization changing element essentially only receives the primary second device light and a second polarization changing element essentially only receives the secondary second device light, the former may be optimized for the primary second device light and the latter may be optimized for the secondary second device light (see also above).

[0088] In relation to the luminescent material pumping and light generation, it is desirable that the first device light that pumps the luminescent material may not end up in the system light (see also above). Further, an optical path may be designed allowing the luminescent material to be pumped and the luminescent material light to be guided away to end up in the system light. To this end, a dichroic mirror may be applied, as the pump light may have a spectral power distribution with intensities at smaller wavelengths and the luminescent material light may have a spectral power distribution with intensities at relatively larger wavelengths. Therefore, in embodiments downstream of the first light generating arrangement and upstream of the luminescent material a second dichroic beam splitter may be configured to reflect at least part of the luminescent material light and transmit at least part of the first device light, or configured to transmit at least part of the luminescent material light and reflect at least part of the first device light.

[0089] 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”.

[0090] With respect to the first light generating arrangement, this arrangement may especially comprise a (first) laser bank. Likewise, respect to the second light generating arrangement, this arrangement may especially comprise a (second) laser bank. A difference between these two arrangements, such as laser banks, may especially be that the first arrangement, such as a first laser bank may essentially consist of a single type of first light generating devices, and the second arrangement, such as a second laser bank, may especially comprise at least two different types of second light generating devices.

[0091] In specific embodiments, the plurality of second light generating devices may comprise (a) a plurality of primary second light generating devices and (b) a plurality of secondary second light generating devices. Hence, in embodiments, the second laser bank may comprise (a) a plurality of primary second light generating devices and (b) a plurality of secondary second light generating devices. In embodiments, the second arrangement may comprise nl primary second light generating devices and n2 secondary second light generating devices. Especially, nl>4 and / or n2>4. In embodiments, 8<nl+n2<80, though other values are herein not excluded.

[0092] In embodiments, the primary second light generating devices and the secondary second light generating devices are evenly distributed over the second light generating arrangement (i.e. especially evenly distributed over the second laser bank). This may be useful for optical homogeneity. It may also be beneficial for control of the shape of the beam of system light. In embodiments, they may be configured in a checkerboard pattern.

[0093] In embodiments, the light generating system may comprise a thermally conductive element configured in thermal contact with the second light generating arrangement (i.e. especially with the second laser bank). Alternatively or additionally, the light generating system may comprise a thermally conductive element configured in thermal contact with the first light generating arrangement (i.e. especially with the first laser bank).

[0094] A thermally conductive element especially comprise thermally conductive material. A thermally conductive material may especially have a thermal conductivity of at least about 20 W / (m*K), like at least about 30 W / (m*K), such as at least about 100 W / (m*K), like especially at least about 200 W / (m*K). In yet further specific embodiments, a thermally conductive material may especially have a thermal conductivity of at least about 10 W / (m*K). In embodiments, the thermally conductive material may comprise one or more of copper, aluminum, silver, gold, silicon carbide, aluminum nitride, boron nitride, aluminum silicon carbide, beryllium oxide, a silicon carbide composite, aluminum silicon carbide, a copper tungsten alloy, a copper molybdenum carbide, carbon, diamond, and graphite. However, in embodiments also magnesium may be applied. Alternatively, or additionally, the thermally conductive material may comprise or consist of aluminum oxide. In embodiments, the thermally conductive element may comprise one or more of a heatsink, a heat spreader, and a two-phase cooling device. In yet other embodiments, the thermally conductive element may be configured in thermal contact with one or more of a heatsink, a heat spreader, and a two-phase cooling device, and may e.g. transfer heat to such heatsink, heat spreader, or two- phase cooling device, via another thermally conductive element.

[0095] Returning to the configuration of the second light generating devices, in (other) embodiments, the second light generating arrangement may comprises a periphery, wherein in average the primary second light generating devices may be configured further away from the periphery than the secondary second light generating devices. Especially, in such embodiments the light generating system comprises a thermally conductive element (see also above) configured in thermal contact with the second light generating arrangement. As the secondary light generating devices, such as red lasers, may need more cooling, this may be a beneficial configuration.

[0096] Further, more blue primary second light generating devices, such as blue LEDs may be necessary, than e.g. red secondary second light generating devices. Therefore, in embodiments the light generating system may comprise more primary second light generating devices than secondary second light generating devices. This may apply to both the homogeneous distribution as well as a more inhomogeneous distribution, such as the substantially peripheral arrangement of the secondary second light generating devices as described above.

[0097] For cooling of the light generating devices, a thermally conductive element in thermal contact with the light generating devices may be useful. For thermal management of the luminescent material, also a thermally conductive element may be applied. However, alternatively or additionally, a solution such as a phosphor wheel may be chosen. Therefore, in embodiments the light generating system may further comprise a rotatable element, wherein the luminescent material is comprised by the rotatable element. Hence, in specific embodiments, the light generating system may comprise a rotatable element, wherein the rotatable element comprises the luminescent material. During operation of the light generating system (in an operational mode of the light generating system) the rotatable element may rotate, such that over time different parts of the luminescent material are irradiated by the device light. This may assist in heat management of the luminescent material. In embodiments, the rotatable element may e.g. comprise one of a phosphor wheel, a rotating phosphor disc, and a rotating rod comprising the luminescent material as a cylindrical track.

[0098] In embodiments, the system may comprise a light exit, like an end window or an (other) optical element, or an opening, from which the system light may escape to the external of the system. 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. The system light may escape from the light exit. Optics, such as e.g. described above, may be applied to provide an optical path to the light exit and / or to beam shape the system light. 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”). The dichroic beam splitters and / or polarizing beam splitters described herein may also be applied as beam combiners, as different types of light may (also) be combined via such beam splitters.

[0099] 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, indicator sign systems, decorative lighting systems, portable systems, automotive applications, (outdoor) road lighting systems, urban lighting systems, green house lighting systems, horticulture lighting, digital projection, or LCD backlighting. The light generating system (or luminaire) may be part of or may be applied in e.g. optical communication systems or disinfection systems.

[0100] 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 devices and second light generating devices, etc.

[0101] The term “centroid wavelength”, also indicated as c, is known in the art, and refers to the wavelength value where half of the light energy is at shorter and half the energy is at longer wavelengths; the value is stated in nanometers (nm). It is the wavelength that divides the integral of a spectral power distribution into two equal parts as expressed by the formula Ze = X A* 1(A) / (S I( A)), where the summation is over the wavelength range of interest, and 1(A) is the spectral energy density (i.e. the integration of the product of the wavelength and the intensity over the emission band normalized to the integrated intensity). The centroid wavelength may e.g. be determined at operation conditions.

[0102] BRIEF DESCRIPTION OF THE DRAWINGS

[0103] 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:

[0104] Figs, la-ld, 2a-2b, 3a-3b, and 4a-4d schematically depict some aspects of the light generating system;

[0105] Fig. 5 shows some embodiments of the second light generating arrangement; and

[0106] Fig. 6 schematically depict some applications.

[0107] The schematic drawings are not necessarily to scale.

[0108] DETAILED DESCRIPTION OF THE EMBODIMENTS

[0109] Fig. la-ld, 2a-2b, 3a-3b, and 4a-4d schematically depict embodiments of a light generating system 1000 comprising a first light generating arrangement 1100, a second light generating arrangement 1200, a luminescent material 200, one or more diffusers 710, and an optional control system 300, as well as some other aspects. Here below, the embodiments of the system are described in general, followed by some specific aspects.

[0110] The first light generating arrangement 1100 may comprise a plurality of first light generating devices 110 configured to generate first device light 111. The first light generating arrangement 1100 may comprise a first laser bank comprising the plurality of first light generating devices 110. The first light generating devices 110 comprise first laser diodes. The second light generating arrangement 1200 may comprise a plurality of second light generating devices 120. The plurality of second light generating devices 120 may comprise (a) one or more primary second light generating devices 1210, configured to generate primary second device light 1211, and (b) one or more secondary second light generating devices 1220, configured to generate secondary second device light 1221. The second light generating arrangement 1200 may comprise a second laser bank comprising the plurality of second light generating devices 120. The plurality of second light generating devices 120 comprise primary second laser diodes and secondary second laser diodes. The former may e.g. emit blue light and the latter may emit e.g. green and / or red light, especially (at least) red light.

[0111] The luminescent material 200 may be configured in a light receiving relationship with the first light generating arrangement 1100 and may be configured to convert at least part of the first device light 111 into luminescent material light 201.

[0112] The first device light 111 may comprise one or more of violet light and blue light. The primary second device light 1211 may comprise blue light. The secondary second device light 1221 may comprise one or more of green, yellow, orange, and red light. The luminescent material light 201 may comprise one or more of green, yellow, orange, and red light. The primary second device light 1211, the secondary second device light 1221, and the luminescent material light 201 have different spectral power distributions.

[0113] The one or more diffusers 710 may be configured in a light receiving relationship with the second light generating arrangement 1200 and are configured to convert at least part of the primary second device light 1211 and at least part of the secondary second device light 1221 into diffused primary second device light 1211 and diffused secondary second device light 1221 (respectively).

[0114] The light generating system 1000 may be configured to generate system light 1001 comprising one or more of the diffused primary second device light 1211, the diffused secondary second device light 1221, and the luminescent material light 201. In an operational mode of the light generating system 1000 the system light 1001 may be white light comprising the diffused primary second device light 1211, the diffused secondary second device light 1221, and the luminescent material light 201. Especially, the control system 300 may be configured to control the first light generating devices 110 and the second light generating devices 120.

[0115] One or more of the following applies: (a) the diffuser 710 may be configured in a reflective mode, and (b) the luminescent material 200 may be configured in a reflective mode. Herein, Figs. 1-3 especially schematically shows reflective modes, whereas Figs. 4 also show some embodiments of transmissive modes.

[0116] In specific embodiments, the light generating system 1000 may comprise one or more diffuser sets 7710. Each diffuser set 7710 may comprise a diffuser arrangement 1710 and a first polarizing beam splitter 1525.

[0117] The diffuser arrangement 1710 may comprise one of the one or more diffusers 710. The (one) diffuser 710 may comprise a polarization maintaining diffusor 710. The diffuser arrangement 1710 may also comprise a polarization changing element 810 configured in an optical path between the second light generating arrangement 1200 and the polarization maintaining diffusor 710. Especially, the polarization changing element 810 may be (a) configured to change s-polarized light or p-polarized light propagating through the polarization changing element 810 to the polarization maintaining diffusor diffuser 710 into elliptically polarized light having a first handedness. The polarization maintaining diffusor 710 may be configured to change at least part of the elliptically polarized light having the first handedness received by the polarization maintaining diffusor 710 into (diffused) elliptically polarized light having the second handedness, and (b) configured to change at least part of the (diffused) elliptically polarized light having the second handedness propagating through the polarization changing element 810 in a direction of a light exit 1090 of the light generating system 1000 (via a first polarizing beam splitter 1525) into (diffused) p-polarized light and / or (diffused s-polarized light, respectively).

[0118] The first polarizing beam splitter 1525 may be configured to reflect at least part of one or more of the primary second device light 1211 and the secondary second device light 1221 having a first polarization, and to transmit at least part of one or more of the primary second device light 1211 and the secondary second device light 1221 having a second polarization, different from the first polarization. Further, the first polarizing beam splitter 1525 may be configured in an optical path between the second light generating arrangement 1200 and the diffuser arrangement 1710. Yet, the first polarizing beam splitter 1525 may be (also) configured in an optical path between the diffuser arrangement 1710 and the light exit 1090 of the light generating system 1000.

[0119] Referring to Figs, la and 1c, there are single diffuser sets 7710. Referring to Figs. 2a and 3a, there are two diffuser sets 7710 (in each system 1000).

[0120] In specific embodiments, the one or more primary second light generating devices 1210 may be configured to generate primary second device light 1211 having a first polarization, and / or the one or more secondary second light generating devices 1220 may be configured to generate secondary second device light 1221 with a second polarization, different from the first polarization.

[0121] Referring e.g. to Fig. 2a, the light generating system 1000 may further comprise a second polarizing beam splitter 2525 configured to reflect at least part of the primary second device light 1211 and transmit at least part of the secondary second device light 1221, or configured to transmit at least part of the primary second device light 1211 and reflect at least part of the secondary second device light 1221.

[0122] The light generating system 1000 may be configured such that in dependence of the polarization of the second device light 1211,1221, at least part of the second device light 1211,1221 propagates from the second polarizing beam splitter 2525 to a first diffuser set 7710’ or to a second diffuser set 7710”.

[0123] Referring to e.g. Fig. 3a, in specific embodiments the light generating system 1000 may further comprise a first dichroic beam splitter 1515 configured to reflect at least part of the primary second device light 1211 and transmit at least part of the secondary second device light 1221, or configured to transmit at least part of the primary second device light 1211 and reflect at least part of the secondary second device light 1221.

[0124] The light generating system 1000 may be configured such that in dependence of a spectral power distribution of the second device light 1211,1221, at least part of the second device light 1211,1221 propagates from the first dichroic beam splitter 1515 to a first diffuser set 7710’ or to a second diffuser set 7710”.

[0125] In specific embodiments, the polarization changing element 810 may comprise a 14 waveplate for one or more wavelengths of the second device light 1211,1221. In dependence of the device light the 14 waveplate, the 14 waveplate may be optimized for blue light, for red light, or for green light or for yellow light.

[0126] Referring to e.g. Figs, la, 1c, 2a, 4a, and 4c, in embodiments downstream of the first light generating arrangement 1100 and upstream of the luminescent material 200 a second dichroic beam splitter 2515 may be configured to reflect at least part of the luminescent material light 201 and transmit at least part of the first device light 111, or configured to transmit at least part of the luminescent material light 201 and reflect at least part of the first device light 111. Referring to Figs, la, 1c, 2a, 3a, 4a, 4c, and especially Fig. 5, in embodiments the plurality of second light generating devices 120 may comprise (a) a plurality of primary second light generating devices 1210 and (b) a plurality of secondary second light generating devices 1220. Referring to embodiment II of Fig. 5, the primary second light generating devices 1210 and the secondary second light generating devices 1220 may evenly distributed over the second light generating arrangement 1200. Referring to embodiment I of Fig. 5, the second light generating arrangement 1200 may comprise a periphery 1207, wherein in average the primary second light generating devices 1210 may be configured further away from the periphery 1207 than the secondary second light generating devices 1220. Especially, in such embodiments (but also in other embodiments), the light generating system 1000 may comprise a thermally conductive element 750 configured in thermal contact with the second light generating arrangement 1200, see also embodiment IV of Fig. 5. Referring to embodiment III of Fig. 5, but this may also apply to e.g. embodiments I and II (and IV), the light generating system 1000 may comprise more primary second light generating devices 1210 than secondary second light generating devices 1220. Referring to Figs, la, 1c, 2a, 3a, 4a, 4c, in specific embodiments the light generating system 1000 may further comprise a rotatable element 2200. The luminescent material 200 may be comprised by the rotatable element 2200.

[0127] In embodiments, the first device light 111 may comprise blue light, the primary second device light 1211 may comprise blue light, and the secondary second device light 1221 may comprise red light. Further, in embodiments the first light generating devices 110 and the primary second light generating devices 1210 may be from the same bin.

[0128] Referring e.g. to the first polarizing beam splitter 1525, see e.g. Fig. la, this beam splitter may be configured to split s and p polarization, but may also be configured to transmit or reflect at least part of the luminescent material light, such that together with the diffused primary second device light and diffused secondary second device light, also luminescent material light may propagate to the light exit.

[0129] Referring e.g. to the second dichroic beam splitter 2525, see e.g. Figs. 1c and 2a, this beam splitter may be configured to (a) transmit at least part of the luminescent material light and reflect at least part of the diffused primary second device light and diffused secondary second device light, or (b) reflect at least part of the luminescent material light and transmit at least part of the diffused primary second device light and diffused secondary second device light, such that together with the diffused primary second device light and diffused secondary second device light, also luminescent material light may propagate to the light exit.

[0130] Referring to e.g. a third polarizing beam splitter 3525, see e.g. Fig. 2a, s and p polarized second device light may be splitted, but diffused primary second device light and diffused secondary second device light may be combined. As schematically depicted, the light generating system 1000 may further comprise a control system 300 configured to control one or more of a color point, correlated color temperature, and color rendering index of the system light 1001. The control system 300 may be configured to individually control (a) one or more primary second light generating devices 1210 and (b) one or more secondary second light generating devices 1220.

[0131] Further, referring to Figs. 4a and 4b in embodiments one or more of the following applies: (a) the diffuser 710 may be configured in a transmissive mode, and (b) the luminescent material 200 may be configured in a transmissive mode. In Fig. 4a, the diffuser 710 is configured in a transmissive mode, but the luminescent material 200 is configured in the reflective mode. In Fig. 4b, both the diffuser 710 and the luminescent material 200 are configured in the transmissive mode.

[0132] Fig. lb schematically shows an embodiment of the transmission of a polarizing beam splitter that may be reflective for one polarization direction of linearly polarized red and blue only; however, the polarizing beam splitter may (also) be transmissive for green and / or yellow light.

[0133] Figs. Id, 2b, 3b, 4b, and 4d schematically depict a dichroic beam splitter that is reflective for green and / or yellow; however, the dichroic beam splitter may be transmissive for red and blue.

[0134] Fig. 6 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. 6 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. 6 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. 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. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

[0135] 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.

[0136] The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In a device claim, or an apparatus claim, or a system claim, enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. In yet a further aspect, the invention (thus) provides a software product, which, when running on a computer is capable of bringing about (one or more embodiments of) the method as described herein. 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. 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.

[0137] 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. 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

CLAIMS:

1. A light generating system (1000) comprising a first light generating arrangement (1100), a second light generating arrangement (1200), a luminescent material (200), one or more diffusers (710), and a control system (300); wherein: the first light generating arrangement (1100) comprises a plurality of first light generating devices (110) configured to generate first device light (111); wherein the first light generating arrangement (1100) comprises a first laser bank comprising the plurality of first light generating devices (110); wherein the first light generating devices (110) comprise first laser diodes; the second light generating arrangement (1200) comprises a plurality of second light generating devices (120); wherein the plurality of second light generating devices (120) comprises (a) one or more primary second light generating devices (1210), configured to generate primary second device light (1211), and (b) one or more secondary second light generating devices (1220), configured to generate secondary second device light (1221); wherein the second light generating arrangement (1200) comprises a second laser bank comprising the plurality of second light generating devices (120); wherein the plurality of second light generating devices (120) comprise primary second laser diodes and secondary second laser diodes; the luminescent material (200) is configured in a light receiving relationship with the first light generating arrangement (1100) and is configured to convert at least part of the first device light (111) into luminescent material light (201); the luminescent material light (201) comprises one or more of green, yellow, orange, and red light; and the primary second device light (1211), the secondary second device light (1221), and the luminescent material light (201) have different spectral power distributions; the one or more diffusers (710) are configured in a light receiving relationship with the second light generating arrangement (1200) and are configured to convert at least part of the primary second device light (1211) and at least part of the secondary second device light (1221) into diffused primary second device light (1211) and diffused secondarysecond device light (1221), respectively, and wherein the one or more diffusers (710) comprise a polarization maintaining diffuser; the light generating system (1000) is configured to generate system light (1001) comprising one or more of the diffused primary second device light (1211), the diffused secondary second device light (1221), and the luminescent material light (201); wherein in an operational mode of the light generating system (1000) the system light (1001) is white light comprising the diffused primary second device light (1211), the diffused secondary second device light (1221), and the luminescent material light (201); the control system (300) is configured to control the first light generating devices (110) and the second light generating devices (120); the luminescent material (200) at least comprises a luminescent material of the type AsBsOn Ce, wherein A comprises one or more of Y, La, Gd, Tb and Lu, and wherein B comprises one or more of Al, Ga, In and Sc; the first device light (111) comprises blue light, wherein the primary second device light (1211) comprises blue light; and wherein the secondary second device light (1221) comprises red light; and the control system (300) being configured to control the first light generating devices (110) and the second light generating devices (120) for controlling one or more of a color point, correlated color temperature, and color rendering index of the system light (1001), and wherein the control system (300) is configured to individually control (a) one or more primary second light generating devices (1210) and (b) one or more secondary second light generating devices (1220).

2. The light generating system (1000) according to claim 1, wherein the following applies: (a) the one or more diffusers (710) are configured in a reflective mode, and (b) the luminescent material (200) is configured in a reflective mode.

3. The light generating system (1000) according to any one of the preceding claims, comprising one or more diffuser sets (7710), wherein each diffuser set (7710) comprises: a diffuser arrangement (1710) comprising (a) one of the one or more diffusers (710), wherein the one diffuser (710) comprises a polarization maintaining diffusor (710), and (b) a polarization changing element (810) configured in an optical path between the second light generating arrangement (1200) and the polarization maintaining diffusor (710);wherein the polarization changing element (810) is (a) configured to change s-polarized light or p-polarized light propagating through the a polarization changing element (810) to the polarization maintaining diffusor diffuser (710) into elliptically polarized light having a first handedness; wherein the polarization maintaining diffusor (710) is configured to change at least part of the elliptically polarized light having the first handedness received by the polarization maintaining diffusor (710) into diffused elliptically polarized light having the second handedness, and (b) configured to change at least part of the diffused elliptically polarized light having the second handedness propagating through the polarization changing element (810) in a direction of a light exit (1090) of the light generating system (1000) via a first polarizing beam splitter (1525) into diffused p-polarized light and / or diffused s-polarized light, respectively; a first polarizing beam splitter (1525) configured to reflect at least part of one or more of the primary second device light (1211) and the secondary second device light (1221) having a first polarization, and to transmit at least part of one or more of the primary second device light (1211) and the secondary second device light (1221) having a second polarization, different from the first polarization; wherein the first polarizing beam splitter (1525) is configured in an optical path between the second light generating arrangement (1200) and the diffuser arrangement (1710) and wherein the first polarizing beam splitter (1525) is also configured in an optical path between the diffuser arrangement (1710) and the light exit (1090) of the light generating system (1000).

4. The light generating system (1000) according to claim 3, wherein the one or more primary second light generating devices (1210) are configured to generate primary second device light (1211) having a first polarization, and wherein the one or more secondary second light generating devices (1220) are configured to generate secondary second device light (1221) with a second polarization, different from the first polarization; wherein the light generating system (1000) further comprises a second polarizing beam splitter (2525) configured to reflect at least part of the primary second device light (1211) and transmit at least part of the secondary second device light (1221), or configured to transmit at least part of the primary second device light (1211) and reflect at least part of the secondary second device light (1221); wherein the light generating system (1000) is configured such that in dependence of the polarization of the second device light (1211,1221), at least part of the second device light (1211,1221) propagates from the second polarizing beam splitter (2525) to a first diffuser set (7710’) or to a second diffuser set (7710”).

5. The light generating system (1000) according to claim 3, further comprising a first dichroic beam splitter (1515) configured to reflect at least part of the primary second device light (1211) and transmit at least part of the secondary second device light (1221), or configured to transmit at least part of the primary second device light (1211) and reflect at least part of the secondary second device light (1221); wherein the light generating system (1000) is configured such that in dependence of a spectral power distribution of the second device light (1211,1221), at least part of the second device light (1211,1221) propagates from the first dichroic beam splitter (1515) to a first diffuser set (7710’) or to a second diffuser set (7710”).

6. The light generating system (1000) according to any one of the preceding claims 3-5, wherein the polarization changing element (810) comprises a % waveplate for one or more wavelengths of the second device light (1211,1221).

7. The light generating system (1000) according to any one of the preceding claims 5 - 6, wherein downstream of the first light generating arrangement (1100) and upstream of the luminescent material (200) a second dichroic beam splitter (2515) is configured to reflect at least part of the luminescent material light (201) and transmit at least part of the first device light (111), or configured to transmit at least part of the luminescent material light (201) and reflect at least part of the first device light (111).

8. The light generating system (1000) according to any one of the preceding claims, wherein the plurality of second light generating devices (120) comprises (a) a plurality of primary second light generating devices (1210) and (b) a plurality of secondary second light generating devices (1220).

9. The light generating system (1000) according to claim 8, wherein the primary second light generating devices (1210) and the secondary second light generating devices (1220) are evenly distributed over the second laser bank.

10. The light generating system (1000) according to claim 8, wherein the second light generating arrangement (1200) comprises a periphery (1207), wherein in average the primary second light generating devices (1210) are configured further away from theperiphery (1207) than the secondary second light generating devices (1220); and wherein the light generating system (1000) comprises a thermally conductive element (750) configured in thermal contact with the second laser bank.

11. The light generating system (1000) according to any one of the preceding claims 8-10, comprising more primary second light generating devices (1210) than secondary second light generating devices (1220).

12. The light generating system (1000) according to any one of the preceding claims, further comprising a rotatable element (2200), wherein the luminescent material (200) is comprised by the rotatable element (2200).

13. The light generating system (1000) according to any one of the preceding claims, wherein the first light generating devices (110) and the primary second light generating devices (1210) are from the same bin.

14. The light generating system (1000) according to claim 1, wherein one or more of the following applies: (a) the one or more diffusers (710) are configured in a transmissive mode, and (b) the luminescent material (200) is configured in a transmissive mode.

15. 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, an automotive lighting device, and an optical wireless communication device, comprising the light generating system (1000) according to any one of the preceding claims.

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