Compact and efficient laser-based light source

Abstract

The invention provides a light generating system (1000) comprising a first light source (10), a first quarter wave plate (721), a first polarization based beam director (1510), a reflective polarization maintaining diffuser (710), a first additional light source arrangement (1120), and a light exit (1090), wherein the first additional light source arrangement (1120) comprises a second light source (20), a first dichroic based beam director (1620), a second quarter wave plate (722), and a second polarization based beam director (1520). The light generating system (1000) is configured to generate in an operational mode of the light generating system (1000) system light (1001) comprising diffused first light source light (11d) and diffused second light source light (21d).

Description

[0001]2024PF80180 1 Compact and efficient laser-based light source FIELD OF THE INVENTION The invention relates to a light generating system. Further, the invention relates to a lighting device comprising such light generating system. BACKGROUND OF THE INVENTION Systems with multiple laser light sources are known in the art. US20200186760A1, for instance, describes an illuminator including a first laser light source section that outputs a first light flux that belongs to a first wavelength band, a second laser light source section that outputs a second light flux that belongs to a second wavelength band, a third laser light source section that outputs a third light flux that belongs to a third wavelength band and has a polarization direction different from those of the first and second light fluxes, a light combiner that combines the first, second, and third light fluxes to produce combined light, and a predetermined band retardation film on the downstream of the light combiner that changes the phase of a light flux that forms the combined light and belongs to the third wavelength band, and the polarization directions of the light fluxes contained in the combined light are aligned on the downstream of the predetermined band retardation film. US20190391476A1 discloses a light source device with a blue laser emitting element, a red laser emitting element, a light combining element, a diffusely reflecting element, a phosphor, a polarization splitting / combining element having a polarization split function, and a first wave plate. The polarization splitting / combining element guides a blue first polarization component obtained by performing polarization split on the light from the blue laser emitting element, and the light from the red laser emitting element to the diffusely reflecting element, and guides a blue second polarization component obtained by performing polarization split on the light from the blue laser emitting element to the phosphor. Then, the polarization splitting / combining element emits red diffused light, blue diffused light, a red polarization split component, and a principal fluorescence component obtained by removing the first red fluorescence component from fluorescence in one direction to thereby generate illumination light. 2024PF80180 2 SUMMARY OF THE INVENTION Systems with multiple lasers from the art may include many and / or complicated optics, which may lead to relatively bulky and / or vulnerable systems. 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. Amongst others, in embodiments it is herein proposed using the same (reflective) diffusor for two or more wavelengths and use quarter wave plates in the additive way. According to a first aspect, the invention provides a light generating system (“system”) comprising a first light source, a first quarter wave plate, a first polarization based beam director, a diffuser, especially a reflective polarization maintaining diffuser, and a first additional light source arrangement. The light generating system may further comprise a light exit. Especially, the first light source is configured to generate first light source light, having a first wavelength λ1. Further, in embodiments the first light source may be selected from the group comprising laser diodes, superluminescent diodes, and stacked multi-junction light- emitting diodes. In embodiments, the first quarter wave plate may be configured in an optical path between the first light source and the diffuser. Especially, the first quarter wave plate may be a quarter wave plate for λ1. In specific embodiments, the first quarter wave plate, together with the diffuser, may be configured to (a) convert light comprising s-polarization into light comprising p-polarization, or (b) convert light comprising p-polarization into light comprising s-polarization. In embodiments, the first polarization based beam director may be configured in an optical path between the first light source and the diffuser. Especially, the first polarization based beam director may be configured upstream of the first quarter wave plate. In embodiments, the light generating system may be configured such that the first light source light received by the first polarization based beam director may comprise linear polarized light. Further, in embodiments the first polarization based beam director may be configured to direct first light source light having a first linear polarization, received by the first polarization based beam director, in an optical path to the diffuser. In embodiments, the diffuser, especially the reflective polarization maintaining diffuser, may be configured to diffuse at least part of the first light source light received by the diffuser into diffused first light source light. Thereby, at least part of (the polarization type of the polarization may be maintained, while, however, the handedness of the polarization may be changed). In embodiments, the first polarization based beam director may (further) configured to direct 2024PF80180 3 diffused first light source light having a linear polarization, received by the first polarization based beam director, in an optical path to the light exit. Especially, the first linear polarization and the second linear polarization may be selected from s-polarization and p-polarization. Yet, the light generating system may thus comprise the first additional light source arrangement. The first additional light source arrangement may in embodiments comprise a second light source, a first dichroic based beam director, a second quarter wave plate, and a second polarization based beam director. Especially, the second light source may be configured to generate second light source light, having a second wavelength λ2. In specific embodiments |λ2-λ1|≥10 nm, like |λ2-λ1|≥20 nm, or |λ2-λ1|≥30 nm, or |λ2-λ1|≥50 nm such as |λ2-λ1|≥70 nm. Further, in embodiments the second light source may be selected from the group comprising laser diodes, superluminescent diodes, and stacked multi-junction light- emitting diodes. In embodiments, the first dichroic based beam director may be configured upstream of the first polarization based beam director. Further, in embodiments the first dichroic based beam director may be configured to direct (first light source light and) second light source light, received by the first dichroic based beam director, in an optical path to the polarization maintaining diffuser. In embodiments, the second quarter wave plate may be configured downstream of the first dichroic based beam director and / or downstream of the second polarization based beam director and / or upstream of the first polarization based beam director. Especially, in embodiments the second quarter wave plate may be configured in an optical path between the second light source and the diffuser. In specific embodiment, the second quarter wave plate may be a quarter wave plate for |λ2-λ1|. In embodiments, the second polarization based beam director may be configured in an optical path between the second light source and the diffuser. Especially, the second polarization based beam director may in embodiments be configured downstream of the first dichroic based beam director and / or upstream of the second quarter wave plate. Further, in embodiments the light generating system may be configured such that the second light source light received by the second polarization based beam director may comprise linear polarized light. Further, in embodiments the second polarization based beam director may be configured to direct second light source light (and first light source light) having a first linear polarization, received by the second polarization based beam director, in an optical path to the diffuser. Further, in embodiments the diffuser may (also) be configured to diffuse at least part of the second light source light received by the diffuser into diffused second light source light (while especially maintaining at least part of (the polarization type (but changing the handedness)) of the polarization). Yet, in embodiments the second polarization based beam director may further 2024PF80180 4 be configured to direct diffused second light light having a second linear polarization, received by the second polarization based beam director, in an optical path to the light exit. Especially, the light generating system may be configured to generate (in an operational mode of the light generating system) system light comprising in embodiments diffused first light source light and diffused second light source light. Hence, in specific embodiments the invention provides a light generating system comprising a first light source, a first quarter wave plate, a first polarization based beam director, a reflective polarization maintaining diffuser, a first additional light source arrangement, and a light exit, wherein: (A) the first light source is configured to generate first light source light, having a first wavelength λ1; wherein the first light source is selected from the group comprising laser diodes, superluminescent diodes, and stacked multi-junction light-emitting diodes; (B) the first quarter wave plate is configured in an optical path between the first light source and the reflective polarization maintaining diffuser; the first quarter wave plate is a quarter wave plate for λ1; wherein the first quarter wave plate together with the reflective polarization maintaining diffuser are configured to (a) convert light comprising s-polarization into light comprising p-polarization, or (b) convert light comprising p-polarization into light comprising s-polarization; (C) the first polarization based beam director is configured in an optical path between the first light source and the reflective polarization maintaining diffuser; the first polarization based beam director is configured upstream of the first quarter wave plate; the light generating system is configured such that the first light source light received by the first polarization based beam director may comprise linear polarized light; wherein the first polarization based beam director is configured to direct first light source light having a first linear polarization, received by the first polarization based beam director, in an optical path to the reflective polarization maintaining diffuser; (D) the reflective polarization maintaining diffuser is configured to diffuse at least part of the first light source light received by the reflective polarization maintaining diffuser into diffused first light source light (while maintaining at least part of (the polarization type (but changing the handedness)) of the polarization); (E) the first polarization based beam director is (further) configured to direct diffused first light source light having a second linear polarization, received by the first polarization based beam director, in an optical path to the light exit; wherein the first linear polarization and the second linear polarization are selected from s-polarization and p- polarization; (F) the first additional light source arrangement comprises a second light source, a first dichroic based beam director, a second quarter wave plate, and a second polarization based beam director; (G) the second light source is configured to generate second light source 2024PF80180 5 light, having a second wavelength λ2; wherein such as wherein |λ2-λ1|≥30 nm; wherein the second light source is selected from the group comprising laser diodes, superluminescent diodes, and stacked multi-junction light-emitting diodes; (H) the first dichroic based beam director is configured upstream of the first polarization based beam director; the first dichroic based beam director is configured to direct first light source light and second light source light, received by the first dichroic based beam director in an optical path to the polarization maintaining diffuser; (I) the second quarter wave plate is configured downstream of the first dichroic based beam director and downstream of the second polarization based beam director and upstream of the first polarization based beam director; the second quarter wave plate is configured in an optical path between the second light source and the reflective polarization maintaining diffuser; the second quarter wave plate is a quarter wave plate for |λ2-λ1|; (J) the second polarization based beam director is configured in an optical path between the second light source and the reflective polarization maintaining diffuser; the second polarization based beam director is configured downstream of the first dichroic based beam director and upstream of the second quarter wave plate; the light generating system is configured such that the second light source light received by the second polarization based beam director may comprise linear polarized light; the second polarization based beam director is configured to direct second light source light (and first light source light) having a first linear polarization, received by the second polarization based beam director, in an optical path to the reflective polarization maintaining diffuser; (K) the reflective polarization maintaining diffuser is (also) configured to diffuse at least part of the second light source light received by the reflective polarization maintaining diffuser into diffused second light source light (while maintaining at least part of (the polarization type (but changing the handedness)) of the polarization); (L) the second polarization based beam director is (further) configured to direct diffused second light source light having a second linear polarization, received by the second polarization based beam director, in an optical path to the light exit; and (M) the light generating system is configured to generate in an operational mode of the light generating system, system light comprising diffused first light source light and diffused second light source light. With such system, relatively high intensity light may be provided, while the system may be relatively compact and robust. Though the light may be high intensity light, the diffused aspect may provide (more) safety and / or a more desirable beam shape. The number of optical components may be limited e.g. saving cost and / or allowing a more compact system. Further, the spectral power distribution of the system light generated by the system may be controllable. Further, the system may comprise a single additional light 2024PF80180 6 source arrangement, but may also comprise than one additional light source arrangement, such as two or three, though more is herein not excluded. This may further allow a high controllability of the spectral power distribution of the system light. The invention will here below described in relation to one, two, or three additional light source arrangements. However, the modular concept also allows higher number of additional light source arrangement. Especially, however, the light generating system may comprise 1-4, such as 1-3, like at least 2 additional light source arrangements. As indicated above, the light generating system may comprise a first light source, a first quarter wave plate, a first polarization based beam director, a reflective polarization maintaining diffuser, and a first additional light source arrangement. Further, the light generating system may comprise a light exit. Especially, the first light source is configured to generate first light source light. Here below, embodiments of the first light source are described. However, these embodiments may equally apply to a second light source, or an optional third light source, or an optional fourth light source. Hence, the below embodiments may apply in general to the herein described light sources. The term “light source” may in principle relate to any light source known in the art. It may be a conventional (tungsten) light bulb, a low pressure mercury lamp, a high pressure mercury lamp, a fluorescent lamp, an LED (light emitting diode). In a specific embodiment, the light source comprises a solid state light source (such as an LED or laser diode (or “diode laser”)). The term “light source” may also relate to a plurality of light sources, such as 2-2000 (solid state) LED light sources. Hence, the term LED may also refer to a plurality of LEDs. Further, the term “light source” may in embodiments also refer to a so-called chip-on-board (COB) light source. The term “COB” especially refers to LED chips in the form of a semiconductor chip that is neither encased nor connected but directly mounted onto a substrate, such as a PCB. Hence, a plurality of light emitting semiconductor light source may be configured on the same substrate. In embodiments, a COB is a multi LED chip configured together as a single lighting module. 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 2024PF80180 7 than 2 mm, such as in the range of e.g.0.2-2 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 “µLEDs”. 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 µm – 1 mm. Herein, the term µ 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 µm and smaller. The wording “the second quarter wave plate is a quarter wave plate for |λ2- λ1|” refers to “a retarder plate providing a (extra) controlled phase difference of one quarter |λ2-λ1| between the two (orthogonal) polarization components of the second light source light. A retarder plate may consist of a plurality of retarder plates fulfilling the same functionality. 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. 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. The term “light source” may refer to a semiconductor light-emitting device, such as a light emitting diode (LEDs), a resonant cavity light emitting diode (RCLED), a vertical cavity laser diode (VCSELs), an edge emitting laser, etc... The term “light source” may also refer to an organic light-emitting diode (OLED), such as a passive-matrix (PMOLED) or an active-matrix (AMOLED). In a specific embodiment, the light source comprises a solid-state light source (such as an LED or laser diode). In an embodiment, the 2024PF80180 8 light source comprises an LED (light emitting . The terms “light source” or “solid state light source” may also refer to a superluminescent diode (SLED). The term LED may also refer to a plurality of LEDs. 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). 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 2024PF80180 9 specific embodiments, the light source may from the group of laser diodes and superluminescent diodes. In other embodiments, the light source may comprise an LED. 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. 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 or 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. 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. 2024PF80180 10 The term “solid state light 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. 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 (Cr:ZnSe) 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 (Al2O3:Cr3+), thulium YAG (Tm:YAG) laser, titanium sapphire (Ti:sapphire; Al2O3:Ti3+) laser, trivalent 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. 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; Al2O3:Ti3+) laser. For instance, considering second and third harmonic generation, such light sources may be used to generated blue light. 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, 2024PF80180 11 AlGaInP, AlGaAs, InGaAsP, lead salt, surface emitting laser (VCSEL), quantum cascade laser, hybrid silicon laser, etc. A laser may be combined with an upconverter in order to arrive at shorter (laser) wavelengths. For instance, with some (trivalent) 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. As can be derived from the below, the term “laser light source” may also refer to a plurality of (different or identical) laser light sources. In specific embodiments, the term “laser light source” may refer to a plurality N of (identical) laser light sources. In embodiments, N=2, or more. In specific embodiments, N may be at least 5, such as especially at least 8. In this way, a higher brightness may be obtained. In embodiments, laser light sources may be arranged in a laser bank (see also above). The laser bank may in embodiments comprise heat sinking and / or optics e.g. a lens to collimate the laser light. Hence, in embodiments lasers in a laser bank (or “laser array bank”) may share the same optics. The laser light source is configured to generate laser light source light (or “laser light”). The light source light may essentially consist of the laser light source light. The light source light may also comprise laser light source light of two or more (different or 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. 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 2024PF80180 12 (slightly) downstream thereof. Especially, 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). 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. 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, especially relative to the propagation of the undiffused first light source light to the reflective polarization maintaining diffuser), 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”. The terms “upstream” and “downstream” herein may especially relate to the order of elements assuming a propagation of light source light to the polarization maintaining diffuser. 2024PF80180 13 The light source light of the sources herein may especially have relatively narrow bands, like full width half maxima of e.g.30 nm or less. Especially, this may apply to solid state light sources as embodiments, like laser diodes. The light source light of the first solid state light source may have essentially any color, and thus have any centroid wavelength. Herein, embodiments are provided wherein the first light source light is blue light, but other colors may also be possible. Especially, the first light source light may having a first wavelength λ1. This first wavelength λ1 may be peak wavelength of the first light source light, but may in principle be any wavelength within the emission band of the first light source light. Especially, however, it may be a wavelength close to the peak wavelength, like within ±10 nm of the peak wavelength. As indicated above, the first light source may in embodiments selected from the group comprising laser diodes, superluminescent diodes, and stacked multi-junction light- emitting diodes. Especially, in embodiments the first light source may comprise a laser diode. The term “centroid wavelength”, also indicated as λc, 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 λc = Σ λ*I(λ) / (Σ I( λ)), where the summation is over the wavelength range of interest, and I(λ) 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. A way to generate diffused light source light, and separate the diffused light source light from an optical path between the light source and the diffuser, is by introducing a polarizing beam splitter and a quarter wave plate between the light source and the diffuser, wherein the diffuser is a reflective polarization maintaining diffuser. Here below, some embodiments of a polarizing beam splitter, a quarter wave plate, and a reflective polarization maintaining diffuser are described. A polarizing beam splitter may be considered an example of redirectional optics. Light propagating to the polarizing beam splitter, and comprising both linear polarizations, like elliptically polarized light, may be split in two orthogonally propagating beams of light with complementary linear polarizations. Hence, this provides the polarizing beam splitter its beam splitting function. However, the opposite may also be true, two beams of light with complementary linear polarizations orthogonally propagating to the polarizing beam splitter may be combined in a single beam comprising both complementary linear 2024PF80180 14 polarizations and propagating along an axis to an axis of one of the two beams of light with complementary linear polarizations orthogonally propagating to the polarizing beam splitter. Hence, for the polarizing beam splitter may apply that for a first polarization, the transmission may be higher, like at least 10% points higher, such as at least 20% points higher, or even at least 30 % points, than for a second polarization. Similarly, for a first polarization, the reflection may be lower, like at least 10% points lower, such as at least 20% points lower, or even at least 30 % points, than for a second polarization. Especially, in embodiments, the polarizing beam splitter may be configured to direct at least 60%, like at least 80%, more especially at least 90%, such as at least about 95%, of the light of the first polarization to a first direction and at least 60%, like at least 80%, more especially at least 90%, such as at least about 95%, of the light of the second polarization to a second direction, wherein the directions may in embodiments have a mutual angle selected from the range 45- 135°, such as about 90°. The percentage of the light may refer to a spectral power (e.g. in Watt). Especially, the first polarization and the second polarization may comprise linear polarizations such as selected from s polarization and p polarization. Optionally, the first polarization and the second polarization may be selected from different elliptically polarized light. In embodiments, the polarizing beam splitters herein may be selected from reflective polarizing beam splitters (reflective polarizers). Hence, the polarization based beam directors herein may also be indicated as polarizing beam splitter or polarizing beam combiner. In most of the embodiments described herein, their function is to combine beams of light having the same polarization while propagating to the reflective polarization maintaining diffuser, while separating from that (same) optical path diffused device light having a different linear polarization propagating away from the reflective polarization maintaining diffuser, and redirection that diffused device light having a different linear polarization propagating in an optical path to the light exit. A quarter wave plate is an example of a polarization converter, such as a birefringent rotator. As known from the art, a waveplate or retarder is an optical device that may alter the polarization state of a light wave travelling through it depending on the orientation of the waveplate relative to the propagation direction and the state of polarization of the light wave. A quarter-wave plate may convert linear polarized light into elliptically (such as especially circularly) polarized light (and vice versa). Especially, herein, in embodiments, the quarter waveplate may be configured to convert linear polarized light 2024PF80180 15 received by the quarter waveplate into as especially circularly) polarized light. Additionally or alternatively, in embodiments, the quarter waveplate may be configured to convert elliptical polarized light (such as especially circularly polarized light) received by the quarter waveplate into linear polarized light. The diffuser may, in embodiments, be configured to diffuse at least part of the device light received by the diffuser system into diffused device light. Especially, in embodiments, the diffuser may be configured to diffuse at least 30%, like at least 50%, such as at least 60%, like at least 70% of the device light, received by the diffuser system, into diffused device light. Especially, in embodiments, the diffuser may be configured to diffuse at least 80%, more especially at least 90%, including 100% of the device light received by the diffuser system into diffused device light. In embodiments, the diffuser may especially comprise a substantially polarization maintaining diffuser, i.e., the diffuser may be configured to substantially maintain the polarization of the incident light upon diffusion (and in some embodiments reflection)(even though the handedness may (thus) change). Such embodiments may be beneficial as depolarization at the diffuser may be reduced, therewith improving the efficiency of the contribution of the diffuser arrangement to the system light. Therefore, in embodiments, the diffuser may comprise a metal coated surface textured glass substrate mounted on a heat conductive material such as e.g. a metal or a ceramic. In such embodiments, the heat conductive material may be configured to conduct away heat that may be generated in the diffuser due to some absorption of incident device light. In embodiments the polarization maintaining diffuser may comprise small- angle diffuse reflector, with a diffusion angle of at maximum 10°. Therefore, in embodiments the diffuser system may comprise an arrangement of a polarization converter and a polarization maintaining diffuser, wherein the polarization maintaining diffuser may comprise small-angle diffuse reflector, with a diffusion angle of at maximum 10°. The small- angle diffuse reflector may comprise a textured metal surface (or metallized textured surface), a meta surface, a diffractive surface, a holographic (volume) diffuser, a stack of a multi-lens array with a specular mirror, a stack of a small-angle transmissive diffusive material (e.g. a volume diffuser, textured surface diffuser, meta surface diffuser, …) with a specular mirror, a retroreflector array with some beam broadening properties, such as a cat- eye spheres array, etc. (see also above). Hence, in embodiments a small-angle reflective diffuser may be realized by a stack of a small-angle transmissive diffuser and a specular mirror. In embodiments, the term “diffusion angle” may refer to the (relatively smooth) 2024PF80180 16 broadening of an incident beam of radiation may be characterized by the full width at half maximum of the diffused radiant angular intensity distribution for an incident (non- diffused) pencil beam (i.e., an incident beam of radiation with a negligible angular extent (FWHM) compared to the FWHM of the diffused beam). In further embodiments, the small- angle diffuse reflector may have a diffusion angle of at minimum 1°, such as at least about 1.5° (the diffusion angle of a specular reflector may thus be 0°). Especially, the diffuser may be configured in the reflective mode. Hence, a reflective polarization maintaining diffuser may herein be applied. The reflective polarization maintaining diffuser may be a diffuser for first light source light, but also for the second light source light, and also for the optional third light source light and the optional fourth light source light, etc. As indicated above, the first quarter wave plate may be configured in an optical path between the first light source and the reflective polarization maintaining diffuser. Especially, the first quarter wave plate is a quarter wave plate for λ1. Further, especially the first quarter wave plate together with the reflective polarization maintaining diffuser are configured to (a) convert light (with the first wavelength) comprising s-polarization into light (with the first wavelength) comprising p-polarization, or (b) convert light (with the first wavelength) comprising p-polarization into light (with the first wavelength) comprising s- polarization. Hence, assuming the first light source be configured to generate first light source light with s-polarization, while propagating to the reflective polarization maintaining diffuser, this polarization is converted into elliptically polarized light having a first handedness by the quarter wave plate, is diffused and converted into (diffused) elliptically polarized light having a second handedness by the reflective polarization maintaining diffuser, propagates back to the quarter wave plate, and is subsequently converted into first light source light with p-polarization by the quarter wave plate. Likewise, assuming the first light source be configured to generate first light source light with p-polarization, while propagating to the reflective polarization maintaining diffuser, this polarization is converted into elliptically polarized light having a second handedness by the quarter wave plate, is diffused and converted into (diffused) elliptically polarized light having a first handedness by the reflective polarization maintaining diffuser, propagates back to the quarter wave plate, and is subsequently converted into first light source light with s-polarization by the quarter wave plate. By introducing a (first) polarization based beam director between the first light source and the quarter wave plate, the first light source light having a first polarization may be directed by the polarization based beam director in the optical path to the reflective 2024PF80180 17 polarization maintaining diffuser, whereas light source light having the second polarization may be directed by the polarization based beam director in the optical path to the light exit. In this way, the first quarter wave plate and the reflective polarization maintaining diffuser together may be configured to (a) convert light (especially first light source light) comprising s-polarization into light comprising p-polarization, or (b) convert light (especially first light source light) comprising p-polarization into light comprising s- polarization. Hence, assuming e.g. s-polarized light propagating from the (first) light source from which the light originates to the reflective polarization maintaining diffuser is s- polarized upstream of the first quarter wave plate, and is converted such that after reflection (and diffusion) at the reflective polarization maintaining diffuser, the light returns, and after passing the first quarter wave plate in opposite direction, it is p-polarized. Similarly, p- polarized light can be converted into s-polarized light. Therefore, the first polarization based beam director may be configured in an optical path between the first light source and the reflective polarization maintaining diffuser. Especially, the first polarization based beam director may be configured upstream of the first quarter wave plate. Hence, relative to the propagation of the undiffused first light source light to the reflective polarization maintaining diffuser the first polarization based beam director may be configured upstream of the first quarter wave plate. Further, the light generating system may be configured such that the first light source light received by the first polarization based beam director may comprise linear polarized light. As indicated above, the first device light reaching the first polarization based beam director may comprise polarized light having a first linear polarization. Yet, the light generating system may be configured such that the first device light reaching the first polarization based beam director may comprise linear polarized light. Hence, the first device light may comprise linear polarized light and / or a polarizer may be configured downstream of the first light source and upstream of the first polarization based beam director such that the first device light reaching the first polarization based beam director may comprise linear polarized light. Hence, (a) the first polarization based beam director may be configured to direct first light source light having a first linear polarization, received by the first polarization based beam director, in an optical path to the reflective polarization maintaining diffuser, (b) the reflective polarization maintaining diffuser may be configured to diffuse at least part of the first light source light received by the reflective polarization maintaining 2024PF80180 18 diffuser into diffused first light source light maintaining at least part of (the polarization type (but changing the handedness)) of the polarization), and (c) the first polarization based beam director may (further) be configured to direct diffused first light source light having a second linear polarization, received by the first polarization based beam director, in an optical path to the light exit. As indicted above, the first linear polarization and the second linear polarization are selected from s-polarization and p-polarization. Now, as indicated above, first light source light may be diffused and redirected from the optical path between the first light source and the reflective polarization maintaining diffuser. However, it is desirable to have one or more further light sources, to allow generating system light having different colors and / or generating white light. To this end, the system may comprise a second solid state light source, which may be comprised in an arrangement that allows introduction of the second light source light in the optical path between the first solid state light source and the reflective polarization maintaining diffuser, converting the second light source light into diffused second light source light, and redirecting from the optical path between the first light source and the reflective polarization maintaining diffuser, to allow propagation further to the light exit. To this end, a first additional light source arrangement is provided. Especially, the first additional light source arrangement may comprise a second light source, a first dichroic based beam director, a second quarter wave plate, and a second polarization based beam director. The light source light of the second solid state light source may have essentially any color, and thus have any centroid wavelength. Especially, the second light source light may having a second wavelength λ2. This second wavelength λ2 may be peak wavelength of the second light source light, but may in principle be any wavelength within the emission band of the second light source light. Especially, however, it may be a wavelength close to the peak wavelength, like within ±10 nm of the peak wavelength. Further, especially the second wavelength may be unequal to the first wavelength. Hence, in embodiments the peak wavelengths of the first light source light and second light source light may differ, like at least about 5 nm, more especially at least about 10 nm. In specific embodiments, the second light source may be configured to generate second light source light, having a second wavelength λ2; wherein |λ2-λ1|≥10 nm, such as |λ2-λ1|≥20 nm, like |λ2- λ1|≥30 nm. In further embodiments, |λ2-λ1|≥40 nm, such as |λ2-λ1|≥50 nm (though smaller values may thus also be possible). In embodiments, (λ2-λ1)≥10 nm, such as (λ2-λ1)≥20 nm, 2024PF80180 19 like (λ2-λ1)≥30 nm. In further embodiments, λ1)≥40 nm, such as (λ2-λ1)≥50 nm (though smaller values may thus also be possible). As indicated above, the second light source may in embodiments selected from the group comprising laser diodes, superluminescent diodes, and stacked multi-junction light-emitting diodes. Especially, in embodiments the second light source may comprise a laser diode. The second light source light may be introduced in the optical path to the polarization maintaining diffuser via a dichroic based beam director. A dichroic element may be an embodiment of a color separation element, such as described in US7070300, which is herein incorporated by reference. Especially, the color separation element may be selected from the group of a dichroic mirror, a dichroic cube, and a diffractive optical element. Optionally, the color separation element maybe provided using a hologram. Especially, the dichroic element may be a dichroic mirror or reflector. A dichroic beam splitter may be considered an example of redirectional optics. Light propagating to the dichroic beam splitter, and comprising intensity at different spectral positions, like light having a broad spectral power distribution, or light having different spectral peaks, or like light comprising a combination of first light having a first centroid wavelength and second light having a second centroid wavelength, different from the first centroid wavelength, etc., may be split in two orthogonally propagating beams of light with complementary linear polarizations. Hence, this provides the dichroic beam splitter its beam splitting function. However, the opposite may also be true, two beams of light with different spectral power distributions orthogonally propagating to the dichroic beam splitter may be combined in a single beam comprising both spectral power distributions and propagating along an axis parallel to an axis of one of the two beams of light with spectral power distributions orthogonally propagating to the dichroic beam splitter. Hence, for the dichroic beam splitter may apply that for a first wavelength range, the wavelength averaged transmission may be higher, like at least 10% points higher, such as at least 20% points higher, or even at least 30 % points, than for a second wavelength range (different from the first wavelength range). Similarly, for a first wavelength range, the wavelength averaged reflection may be lower, like at least 10% points lower, such as at least 20% points lower, or even at least 30 % points, than for a second wavelength range. Especially, in embodiments, the dichroic beam splitter may be configured to direct at least 60%, like at least 80%, more especially at least 90%, such as at least about 95%, of (first) light having the first wavelength to a first direction and at least 60%, like at least 80%, more 2024PF80180 20 especially at least 90%, such as at least about of (second) light of the second wavelength to a second direction, wherein the directions may in embodiments have a mutual angle selected from the range 45-135°, such as about 90°. In embodiments, the first light may have a first centroid wavelength and the second light may have a second centroid wavelength, which may differ at least 5 nm, more especially at least about 10 nm. In embodiments the centroid wavelengths may differ at least about 15 nm. The percentage of the light may refer to a spectral power (e.g. in Watt). Hence, the dichroic based beam directors herein may also be indicated as dichroic beam splitter or dichroic beam combiner. In most of the embodiments described herein, their function is to combine beams of light having different spectral power distributions, reaching the dichroic based beam directors in an orthogonal way, and propagating in the same optical path downstream of the dichroic based beam directors. In embodiments, the first dichroic based beam director may be configured upstream of the first polarization based beam director. Hence, second light source light propagating from the second light source in the direction of the polarization maintaining diffuser may propagate via the first dichroic based beam director and then via the first polarization based beam director. Further, in embodiments the first dichroic based beam director may be configured to direct (first light source light) and second light source light, received by the first dichroic based beam director in an optical path to the polarization maintaining diffuser. In this way, second light source light may be brought in at least part of the path length of the optical path between the first light source and the polarization maintaining diffuser. The second quarter wave plate may be used in the additive way (with the first quarter wave plate), as the second light source light may propagate – in the following order op propagation (but not including all optics, only for the sake of argument the relevant optics are mention) - via the second quarter wave plate, via the first quarter wave plate, via the polarization maintaining diffuser, again via the first quarter wave plate, and then also again via the second quarter wave plate. In this way, the second quarter wave plate, the first quarter wave plate, and the reflective polarization maintaining diffuser together may be configured to (a) convert light (especially second light source light) comprising s-polarization into light comprising p- polarization, or (b) convert light (especially second light source light) comprising p- polarization into light comprising s-polarization. Hence, s-polarized light propagating from the light source from which the light originates to the reflective polarization maintaining 2024PF80180 21 diffuser is s-polarized upstream of the second wave plate, and is converted such that after reflection (and diffusion) at the reflective polarization maintaining diffuser, the light returns, and after passing the second quarter wave plate in opposite direction, it is p- polarized. Similarly, p-polarized light can be converted into s-polarized light. Hence, in embodiments the second quarter wave plate may be configured downstream of the first dichroic based beam director and (may be configured) downstream of the second polarization based beam director and (may be configured) upstream of the first polarization based beam director. Hence, second light source light propagating from the second light source to reflective polarization maintaining diffuser may propagate via the first dichroic based beam director, subsequently via the second polarization based beam director, subsequently via the second quarter wave plate, and subsequently via the first polarization based beam director. Further, especially the second quarter wave plate may be configured in an optical path between the second light source and the reflective polarization maintaining diffuser. Especially, in embodiments the second quarter wave plate may be a quarter wave plate for |λ2-λ1|. Further, in specific embodiments λ2>λ1. Whereas the first dichroic based beam director may be used to introduce the second device light into the optical path between the first light source and the reflective polarization maintaining diffuser, the second polarization based beam director may be used to redirect diffused second device light from this optical path into an optical path to the light exit. Hence, the second polarization based beam director may be configured in an optical path between the second light source and the reflective polarization maintaining diffuser. Especially, the second polarization based beam director may in embodiments be configured downstream of the first dichroic based beam director and upstream of the second quarter wave plate. Further, in embodiments, the light generating system may be configured such that the second light source light received by the second polarization based beam director may comprise linear polarized light. Hence, the second device light may comprise linear polarized light and / or a polarizer may be configured downstream of the second light source and upstream of the second polarization based beam director such that the second device light reaching the second polarization based beam director may comprise linear polarized light. Further, in embodiments the second polarization based beam director may be configured to direct second light source light (and first light source light) having a first linear 2024PF80180 22 polarization, received by the second based beam director, in an optical path to the reflective polarization maintaining diffuser. Further, the reflective polarization maintaining diffuser may (thus) (also) be configured to diffuse at least part of the second light source light received by the reflective polarization maintaining diffuser into diffused second light source light. Thereby, at least part of (the polarization type) of the polarization may be maintained, though the handedness may be changed. Diffused second device light may propagate from the reflective polarization maintaining diffuser along the (same) optical path in the direction of the first dichroic based beam director, but may be directed away from this optical path by second polarization based beam director, which may direct the diffused second device light in an optical path to the light exit. Hence, in embodiments the second polarization based beam director may (further) be configured to direct diffused second light source light having a second linear polarization, received by the second polarization based beam director, in an optical path to the light exit. In embodiments, the system may comprise a light exit, like an end window or an (other) optical element, like a lens, or an opening, from which the system light may escape to the external of the system. The system may comprise a housing, comprising such light exit. The housing may at least partly enclose one or more solid state light sources and one or more (other) optical elements. Especially, the light generating system may be configured to generate in an operational mode of the light generating system, system light comprising diffused first light source light and diffused second light source light. This light may escape from the light exit and thus be indicated as “system light”. The first light source and the one or more further light sources may be controlled by a control system. The control system may be external of the light generating system or may be comprised by the light generating system. In an operational mode, both the first and second light sources may produce light, thereby providing system light comprise both diffused first light source light and diffused second light source light. In embodiments, the control system may be configured to individually control the solid state light sources, thereby also controlling a spectral power distribution of the system light. In operational modes, it may also be possible that not all solid state light sources are operated. 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 2024PF80180 23 (determining the behavior or supervising the 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. 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. 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. 2024PF80180 24 Likewise, this may not exclude that before the mode and / or after executing the mode one or more other modes may be executed. 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). 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. Here below, some further embodiments are described, such as in relation to the first light source and the second light source, but also in relation to further additional light source arrangement, and their respective components. In embodiments, the first light source may be configured to generate first light source light having a first peak wavelength λp,1 selected from the wavelength range of 430- 490 nm, such as selected from the wavelength range of 440-480 nm. Hence, the first light source light may be blue(ish) light. In embodiments, the first wavelength λ1 may be selected from the wavelength range of λp,1± 10 nm, such as selected from the wavelength range of λp,1± 5 nm, like selected from the wavelength range of λp,1 ± 2 nm, more especially selected from the wavelength range of λp,1 ± 1 nm. Further, in embodiments the second light source may be configured to generate second light source light having a second peak wavelength λp,2 selected from the wavelength range of 430-680 nm. Hence, in embodiments this may be blue(ish) light, green light, yellow light, orange light, or red light. Especially, however, in embodiments |λp,2- λp,1|≥10 nm, more especially |λp,2-λp,1|≥20 nm, like |λp,2-λp,1|≥30 nm. Yet, in embodiments |λp,2-λp,1|≥40 nm, such as in specific embodiments |λp,2-λp,1|≥50 nm, though smaller values may thus be possible. In embodiments, the second wavelength λ2may be selected from the wavelength range of λp,2 ± 10 nm, such as selected from the wavelength range of λp,2 ± 5 nm, like selected from the wavelength range of λp,2± 2 nm, more especially selected from the wavelength range of λp,2 ± 1 nm. Yet, in specific embodiments the first light source may comprise a laser diode, and the second light source may comprise a laser diode. The diffused first light source light and diffused second light source light may be combined by a dichroic beam combiner (see also above where the dichroic beam splitter is 2024PF80180 25 described). Hence, in embodiments the light system may comprise a first dichroic- based combiner, configured to (a) combine the diffused first light source light and diffused second light source light, and (b) direct the combined diffused first light source light and diffused second light source light in an optical path to the light exit. Now, as indicated above, first light source light and second light source light may be diffused and redirected from the respective optical paths between the respective light source and the reflective polarization maintaining diffuser. However, it may be desirable to have two or more further light sources, to allow generating system light having different colors and / or generating white light. To this end, the system may comprise yet a further (a third) solid state light source, which may be comprised in an arrangement that allows introduction of the third light source light in the optical path between the first solid state light source and reflective polarization maintaining diffuser, converting the third light source light into diffused third light source light, and redirecting from the optical path between the first light source and the reflective polarization maintaining diffuser, to allow propagation further to the light exit. To this end, a second additional light source arrangement is provided. Hence, in embodiments the light generating system may further comprise a second additional light source arrangement. Especially, in embodiments the second additional light source arrangement may comprise a third light source, a second dichroic based beam director, a third quarter wave plate, and a third polarization based beam director. The wording “the third quarter wave plate is a quarter wave plate for |λ3-λ2|” refers to “a retarder plate providing a (extra) controlled phase difference of one quarter |λ3- λ2| between the two (orthogonal) polarization components of the third light source light. A retarder plate may consist of a plurality of retarder plates fulfilling the same functionality. The light source light of the third solid state light source may have essentially any color, and thus have any centroid wavelength. Especially, the third light source light may having a third wavelength λ3. This third wavelength λ3may be peak wavelength of the third light source light, but may in principle be any wavelength within the emission band of the third light source light. Especially, however, it may be a wavelength close to the peak wavelength, like within ±10 nm of the peak wavelength. Further, especially the third wavelength may be unequal to the first wavelength and / or the second wavelength. Hence, in embodiments the peak wavelengths of the first light source light and third light source light may differ, like at least about 5 nm, more especially at least about 10 nm, and in embodiments the peak wavelengths of the second light source light and third light source light may differ, like at least about 5 nm, more especially at least about 10 nm. In specific 2024PF80180 26 embodiments, the third light source may be to generate third light source light, having a third wavelength λ3. In embodiments, |λ3-λ1|≥10 nm, such as |λ3-λ1|≥20 nm, like |λ3- λ1|≥30 nm. Alternatively or additionally, in embodiments |λ3-λ2|≥10 nm, such as |λ3-λ2|≥20 nm, or |λ2-λ1|≥30 nm, or |λ2-λ1|≥50 nm like |λ3-λ2|≥70 nm. In further embodiments, |λ3-λ1|≥40 nm, such as |λ3-λ1|≥50 nm (though smaller values may thus also be possible). Alternatively or additionally, in further embodiments, |λ3-λ2|≥40 nm, such as |λ3-λ2|≥50 nm (though smaller values may thus also be possible). As indicated above, the third light source may in embodiments selected from the group comprising laser diodes, superluminescent diodes, and stacked multi-junction light-emitting diodes. Especially, in embodiments the third light source may comprise a laser diode. As can be derived from the above, the third light source light may (also) be introduced in the optical path to the polarization maintaining diffuser via a dichroic based beam director. Hence, in embodiments the second dichroic based beam director may be configured upstream of the second polarization based beam director. Further, the second dichroic based beam director may in embodiments be configured to direct first light source light and third light source light, received by the second dichroic based beam director, in an optical path to the polarization maintaining diffuser. In this way, third light source light may be brought in at least part of the path length of the optical path between the first light source and the polarization maintaining diffuser. The third quarter wave plate may be used in the additive way (with the first quarter wave plate and the second quarter wave plate), as the third light source light may propagate – in the following order op propagation (but not including all optics, only for the sake of argument the relevant optics are mention) - via the third quarter wave plate, via the second quarter wave plate, via the first quarter wave plate, via the polarization maintaining diffuser, again via the first quarter wave plate, the second quarter wave plate, and then also again via the third quarter wave plate. In this way, the third quarter wave plate, the second quarter wave plate, the first quarter wave plate, and the reflective polarization maintaining diffuser together may be configured to (a) convert light (especially third light source light) comprising s-polarization into light comprising p-polarization, or (b) convert light (especially third light source light) comprising p-polarization into light comprising s-polarization. Hence, s-polarized light propagating from the light source from which the light originates to the reflective polarization maintaining diffuser is s-polarized upstream of the third quarter wave plate, and 2024PF80180 27 is converted such that after reflection (and at the reflective polarization maintaining diffuser, the light returns, and after passing the third quarter wave plate in opposite direction, it is p-polarized. Similarly, p-polarized light can be converted into s- polarized light. Hence, in embodiments the third quarter wave plate may be configured downstream of the second dichroic based beam director and downstream of the third polarization based beam director and upstream of the second polarization based beam director. Yet, in embodiments the third quarter wave plate may be configured in an optical path between the third light source and the reflective polarization maintaining diffuser. Especially, in embodiments the third quarter wave plate may be a quarter wave plate for |λ3- λ2|. Hence, third light source light propagating from the third light source to reflective polarization maintaining diffuser may propagate via the second dichroic based beam director, subsequently via the third polarization based beam director, subsequently via the third quarter wave plate, and subsequently via the second polarization based beam director. Note that in the optical path from the third quarter wave plate to the second polarization based beam director, the first dichroic based beam director may be configured. Whereas the second dichroic based beam director may be used to introduce the third device light into the optical path between the first light source and the reflective polarization maintaining diffuser, the third polarization based beam director may be used to redirect diffused third device light from this optical path into an optical path to the light exit. Hence, in embodiments the third polarization based beam director may be configured in an optical path between the third light source and the reflective polarization maintaining diffuser. Further, in embodiments the third polarization based beam director may be configured downstream of the second dichroic based beam director and upstream of the third quarter wave plate. Especially, the light generating system may be configured such that the third light source light received by the third polarization based beam director may comprise linear polarized light. Hence, the third device light may comprise linear polarized light and / or a polarizer may be configured downstream of the third light source and upstream of the third polarization based beam director such that the third device light reaching the third polarization based beam director may comprise linear polarized light. Further, in embodiments, the third polarization based beam director may be configured to direct third light source light (and first light source light) having a first linear polarization, received by 2024PF80180 28 the third polarization based beam director, in optical path to the reflective polarization maintaining diffuser. Further, the reflective polarization maintaining diffuser may (thus) (also) be configured to diffuse at least part of the third light source light received by the reflective polarization maintaining diffuser into diffused third light source light. Thereby, at least part of (the polarization type) of the polarization may be maintained, though the handedness may be changed. Diffused third device light may propagate from the reflective polarization maintaining diffuser along the (same) optical path in the direction of the second dichroic based beam director, but may be directed away from this optical path by third polarization based beam director, which may direct the diffused third device light in an optical path to the light exit. Hence, in embodiments the third polarization based beam director may (further) be configured to direct diffused third light source light having a second linear polarization, received by the third polarization based beam director, in an optical path to the light exit. Hence, similarly as indicated above, in embodiments the light generating system may be configured to generate in an operational mode of the light generating system, system light comprising diffused first light source light, diffused second light source light, and diffused third light source light. Similarly as defined above, in an operational mode, the first and second and third light sources may produce light, thereby providing system light comprise diffused first light source light, diffused second light source light, and diffused third light source light. In embodiments, the control system may be configured to individually control the solid state light sources, thereby also controlling a spectral power distribution of the system light. In operational modes, it may also be possible that not all solid state light sources are operated, like only one or two of the three (solid state) light sources. In embodiments, the first light source may be configured to generate first light source light having a first peak wavelength λp,1 selected from the wavelength range of 430- 490 nm, such as selected from the wavelength range of 440-480 nm. Hence, the first light source light may be blue(ish) light. In embodiments, the first wavelength λ1 may be selected from the wavelength range of λp,1± 10 nm, such as selected from the wavelength range of λp,1± 5 nm, like selected from the wavelength range of λp,1 ± 2 nm, more especially selected from the wavelength range of λp,1± 1 nm. Further, in embodiments the second light source may be configured to generate second light source light having a second peak wavelength λp,2selected from the 2024PF80180 29 wavelength range of 430-680 nm. Hence, in this may be blue(ish) light, green light, yellow light, orange light, or red light. Especially, however, in embodiments |λp,2- λp,1|≥10 nm, more especially |λp,2-λp,1|≥20 nm, like |λp,2-λp,1|≥30 nm. Yet, in embodiments |λp,2-λp,1|≥40 nm, such as in specific embodiments |λp,2-λp,1|≥50 nm, though smaller values may thus be possible. In embodiments, the second wavelength λ2may be selected from the wavelength range of λp,2 ± 10 nm, such as selected from the wavelength range of λp,2 ± 5 nm, like selected from the wavelength range of λp,2± 2 nm, more especially selected from the wavelength range of λp,2 ± 1 nm. Further, in embodiments the third light source may be configured to generate third light source light having a third peak wavelength λp,3 selected from the wavelength range of 430-680 nm. Hence, in embodiments this may be blue(ish) light, green light, yellow light, orange light, or red light. Especially, however, in embodiments |λp,3-λp,1|≥10 nm, more especially |λp,3-λp,1|≥20 nm, like |λp,3-λp,1|≥30 nm. Yet, in embodiments |λp,3-λp,1|≥40 nm, such as in specific embodiments |λp,3-λp,1|≥50 nm, though smaller values may thus be possible. Further, especially, in embodiments |λp,3-λp,2|≥10 nm, more especially |λp,3-λp,2|≥20 nm, like |λp,3-λp,2|≥30 nm. Yet, in embodiments |λp,3-λp,2|≥40 nm, such as in specific embodiments |λp,3- λp,2|≥50 nm, though smaller values may thus be possible. In embodiments, the third wavelength λ3 may be selected from the wavelength range of λp,3 ± 10 nm, such as selected from the wavelength range of λp,3± 5 nm, like selected from the wavelength range of λp,3± 2 nm, more especially selected from the wavelength range of λp,3 ± 1 nm. In embodiments, (λ2-λ1)≥10 nm, such as (λ2-λ1)≥20 nm, like (λ2-λ1)≥30 nm. In further embodiments, (λ2-λ1)≥40 nm, such as (λ2-λ1)≥50 nm (though smaller values may thus also be possible). In further embodiments, (λ3-λ2)≥10 nm, such as (λ3-λ2)≥20 nm, like (λ3- λ2)≥30 nm. In further embodiments, (λ3-λ2)≥40 nm, such as (λ3-λ2)≥50 nm (though smaller values may thus also be possible). Yet, in specific embodiments the first light source may comprise a laser diode, the second light source may comprise a laser diode, and the third light source may comprise a laser diode. In specific embodiments, however, the second peak wavelength λp,2 may be selected from the wavelength range of 490-590 nm, and the third peak wavelength λp,3may be selected from the wavelength range of 590-680 nm. The diffused first light source light, the diffused second light source light, and the diffused third light source light may be combined by one or more dichroic beam combiner (see also above where the dichroic beam splitter is described). Hence, in 2024PF80180 30 embodiments the light generating system dichroic-based combiners (1710,1720...), configured to (a) combine the diffused first light source light, diffused second light source light, and diffused third light source light, and (b) direct the combined diffused first light source light, diffused second light source light, and diffused third light source light in an optical path to the light exit. Now, as indicated above, first light source light, second light source light, and third light source light may be diffused and redirected from the respective optical paths between the respective light source and the reflective polarization maintaining diffuser. However, it may be desirable to have three or more further light sources, to allow generating system light having different colors and / or generating white light. To this end, the system may comprise yet a further (a fourth) solid state light source, which may be comprised in an arrangement that allows introduction of the fourth light source light in the optical path between the first solid state light source and reflective polarization maintaining diffuser, converting the fourth light source light into diffused fourth light source light, and redirecting from the optical path between the first light source and the reflective polarization maintaining diffuser, to allow propagation further to the light exit. To this end, a third additional light source arrangement is provided. Hence, in embodiments the light generating system may further comprise a third additional light source arrangement. Especially, in embodiments the third additional light source arrangement may comprise a fourth light source, a third dichroic based beam director, a fourth quarter wave plate, and a fourth polarization based beam director. The wording “the fourth quarter wave plate is a quarter wave plate for |λ4-λ3|” refers to “a retarder plate providing a (extra) controlled phase difference of one quarter |λ4- λ3| between the two (orthogonal) polarization components of the second light source light. A retarder plate may consist of a plurality of retarder plates fulfilling the same functionality. The light source light of the fourth solid state light source may have essentially any color, and thus have any centroid wavelength. Especially, the fourth light source light may having a fourth wavelength λ4. This fourth wavelength λ4may be peak wavelength of the fourth light source light, but may in principle be any wavelength within the emission band of the fourth light source light. Especially, however, it may be a wavelength close to the peak wavelength, like within ±10 nm of the peak wavelength. Further, especially the fourth wavelength may be unequal to the first wavelength and / or the second wavelength and / or the third wavelength. Hence, in embodiments the peak wavelengths of the first light source light and fourth light source light may differ, like at least about 5 nm, more especially at least 2024PF80180 31 about 10 nm, and in embodiments the peak of the second light source light and fourth light source light may differ, like at least about 5 nm, more especially at least about 10 nm, and in embodiments the peak wavelengths of the third light source light and fourth light source light may differ, like at least about 5 nm, more especially at least about 10 nm. In specific embodiments, the fourth light source may be configured to generate fourth light source light, having a fourth wavelength λ4. In embodiments, |λ4-λ1|≥10 nm, such as |λ4-λ1|≥20 nm, like |λ4-λ1|≥30 nm. Alternatively or additionally, in embodiments |λ4-λ2|≥10 nm, such as |λ4-λ2|≥20 nm, like |λ4-λ2|≥30 nm. Alternatively or additionally, in embodiments |λ4-λ3|≥10 nm, such as |λ4-λ3|≥20 nm, or |λ2-λ1|≥30 nm, or |λ2-λ1|≥50 nm, like |λ4-λ2|≥70 nm. In further embodiments, |λ4-λ1|≥40 nm, such as |λ4-λ1|≥50 nm (though smaller values may thus also be possible). Alternatively or additionally, in further embodiments, |λ4-λ2|≥40 nm, such as |λ4-λ2|≥50 nm (though smaller values may thus also be possible). Yet alternatively or additionally, in further embodiments, |λ4-λ3|≥40 nm, such as |λ4-λ3|≥50 nm (though smaller values may thus also be possible). As indicated above, the fourth light source may in embodiments selected from the group comprising laser diodes, superluminescent diodes, and stacked multi-junction light- emitting diodes. Especially, in embodiments the fourth light source may comprise a laser diode. As can be derived from the above, the fourth light source light may (also) be introduced in the optical path to the polarization maintaining diffuser via a dichroic based beam director. Hence, in embodiments the third dichroic based beam director may be configured upstream of the third polarization based beam director. Further, the third dichroic based beam director may in embodiments be configured to direct first light source light and fourth light source light, received by the third dichroic based beam director in an optical path to the polarization maintaining diffuser. In this way, fourth light source light may be brought in at least part of the path length of the optical path between the first light source and the polarization maintaining diffuser. The fourth quarter wave plate may be used in the additive way (with the first quarter wave plate and the second quarter wave plate and the third quarter wave plate), as the fourth light source light may propagate – in the following order op propagation (but not including all optics, only for the sake of argument the relevant optics are mention) - via the fourth quarter wave plate, via the third quarter wave plate, via the second quarter wave plate, via the first quarter wave plate, via the polarization maintaining diffuser, again via the first 2024PF80180 32 quarter wave plate, via the second quarter plate, via the third quarter wave plate and then also again via the fourth quarter wave plate. In this way, the fourth quarter wave plate, the third quarter wave plate, the second quarter wave plate, the first quarter wave plate, and the reflective polarization maintaining diffuser together may be configured to (a) convert light (fourth light source light) comprising s-polarization into light comprising p-polarization, or (b) convert light (especially fourth light source light) comprising p-polarization into light comprising s-polarization. Hence, s-polarized light propagating from the light source from which the light originates to the reflective polarization maintaining diffuser is s-polarized upstream of the fourth quarter wave plate, and is converted such that after reflection (and diffusion) at the reflective polarization maintaining diffuser, the light returns, and after passing the fourth quarter wave plate in opposite direction, it is p-polarized. Similarly, p-polarized light can be converted into s-polarized light. Hence, in embodiments the fourth quarter wave plate may be configured downstream of the third dichroic based beam director and downstream of the fourth polarization based beam director and upstream of the third polarization based beam director. Further, in embodiments the fourth quarter wave plate may be configured in an optical path between the fourth light source and the reflective polarization maintaining diffuser. Especially, in embodiments the fourth quarter wave plate may be a quarter wave plate for |λ4- λ3|. Hence, fourth light source light propagating from the fourth light source to reflective polarization maintaining diffuser may propagate via the third dichroic based beam director, subsequently via the fourth polarization based beam director (1540), subsequently via the fourth quarter wave plate (724), and subsequently via the third polarization based beam director (1530). Note that in the optical path from the fourth quarter wave plate (724) to the third polarization based beam director (1530), the second dichroic based beam director (1630) may be configured. Whereas the third dichroic based beam director may be used to introduce the fourth device light into the optical path between the first light source and the reflective polarization maintaining diffuser, the fourth polarization based beam director may be used to redirect diffused fourth device light from this optical path into an optical path to the light exit. Hence, in embodiments the fourth polarization based beam director may be configured in an optical path between the fourth light source and the reflective polarization 2024PF80180 33 maintaining diffuser. Further, in fourth polarization based beam director may be configured downstream of the third dichroic based beam director and upstream of the fourth quarter wave plate. Especially, the light generating system may be configured such that the fourth light source light received by the fourth polarization based beam director may comprise linear polarized light. Hence, the fourth device light may comprise linear polarized light and / or a polarizer may be configured downstream of the fourth light source and upstream of the fourth polarization based beam director such that the fourth device light reaching the fourth polarization based beam director may comprise linear polarized light. Further, in embodiments the fourth polarization based beam director may be configured to direct fourth light source light (and first light source light) having a first linear polarization, received by the fourth polarization based beam director, in an optical path to the reflective polarization maintaining diffuser. Further, the reflective polarization maintaining diffuser may (thus) (also) be configured to diffuse at least part of the fourth light source light received by the reflective polarization maintaining diffuser into diffused fourth light source light. Thereby, at least part of (the polarization type) of the polarization may be maintained, though the handedness may be changed. Diffused fourth device light may propagate from the reflective polarization maintaining diffuser along the (same) optical path in the direction of the third dichroic based beam director, but may be directed away from this optical path by fourth polarization based beam director, which may direct the diffused fourth device light in an optical path to the light exit. Hence, in embodiments the fourth polarization based beam director may (further) be configured to direct diffused fourth light source light having a second linear polarization, received by the fourth polarization based beam director, in an optical path to the light exit. Hence, similarly as defined above, in embodiments the light generating system may be configured to generate in an operational mode of the light generating system, system light comprising diffused first light source light, diffused second light source light, diffused third light source light, and diffused fourth light source light. Similarly as defined above, in an operational mode, the first and second and third and fourth light sources may produce light, thereby providing system light that may comprise diffused first light source light, diffused second light source light, diffused third light source light, and diffused fourth light source light. In embodiments, the control system may be configured to individually control the solid state light sources, thereby also controlling a spectral power distribution of the system light. In operational modes, it may also 2024PF80180 34 be possible that not all solid state light operated, like only one or two or three of the four (solid state) light sources. In embodiments, the first light source may be configured to generate first light source light having a first peak wavelength λp,1 selected from the wavelength range of 430- 490 nm, such as selected from the wavelength range of 440-480 nm. Hence, the first light source light may be blue(ish) light. In embodiments, the first wavelength λ1 may be selected from the wavelength range of λp,1± 10 nm, such as selected from the wavelength range of λp,1± 5 nm, like selected from the wavelength range of λp,1 ± 2 nm, more especially selected from the wavelength range of λp,1± 1 nm. Further, in embodiments the second light source may be configured to generate second light source light having a second peak wavelength λp,2selected from the wavelength range of 430-680 nm. Hence, in embodiments this may be blue(ish) light, green light, yellow light, orange light, or red light. Especially, however, in embodiments |λp,2- λp,1|≥10 nm, more especially |λp,2-λp,1|≥20 nm, like |λp,2-λp,1|≥30 nm. Yet, in embodiments |λp,2-λp,1|≥40 nm, such as in specific embodiments |λp,2-λp,1|≥50 nm, though smaller values may thus be possible. In embodiments, the second wavelength λ2 may be selected from the wavelength range of λp,2± 10 nm, such as selected from the wavelength range of λp,2± 5 nm, like selected from the wavelength range of λp,2 ± 2 nm, more especially selected from the wavelength range of λp,2± 1 nm. Further, in embodiments the third light source may be configured to generate third light source light having a third peak wavelength λp,3 selected from the wavelength range of 430-680 nm. Hence, in embodiments this may be blue(ish) light, green light, yellow light, orange light, or red light. Especially, however, in embodiments |λp,3-λp,1|≥10 nm, more especially |λp,3-λp,1|≥20 nm, like |λp,3-λp,1|≥30 nm. Yet, in embodiments |λp,3-λp,1|≥40 nm, such as in specific embodiments |λp,3-λp,1|≥50 nm, though smaller values may thus be possible. Further, especially, in embodiments |λp,3-λp,2|≥10 nm, more especially |λp,3-λp,2|≥20 nm, like |λp,3-λp,2|≥30 nm. Yet, in embodiments |λp,3-λp,2|≥40 nm, such as in specific embodiments |λp,3- λp,2|≥50 nm, though smaller values may thus be possible. In embodiments, the third wavelength λ3 may be selected from the wavelength range of λp,3 ± 10 nm, such as selected from the wavelength range of λp,3± 5 nm, like selected from the wavelength range of λp,3± 2 nm, more especially selected from the wavelength range of λp,3 ± 1 nm. Further, in embodiments the fourth light source may be configured to generate fourth light source light having a fourth peak wavelength λp,4 selected from the wavelength range of 430-680 nm. Hence, in embodiments this may be blue(ish) light, green light, yellow 2024PF80180 35 light, orange light, or red light. Especially, in embodiments |λp,4-λp,1|≥10 nm, more especially |λp,4-λp,1|≥20 nm, like |λp,4-λp,1|≥30 nm. Yet, in embodiments |λp,4-λp,1|≥40 nm, such as in specific embodiments |λp,4-λp,1|≥50 nm, though smaller values may thus be possible. Further, especially, in embodiments |λp,4-λp,2|≥10 nm, more especially |λp,4-λp,2|≥20 nm, like |λp,4-λp,2|≥30 nm. Yet, in embodiments |λp,4-λp,2|≥40 nm, such as in specific embodiments |λp,4- λp,2|≥50 nm, though smaller values may thus be possible. Further, especially, in embodiments |λp,4-λp,3|≥10 nm, more especially |λp,4-λp,3|≥20 nm, like |λp,4-λp,3|≥30 nm. Yet, in embodiments |λp,4-λp,3|≥40 nm, such as in specific embodiments |λp,4-λp,3|≥50 nm, though smaller values may thus be possible. In embodiments, the fourth wavelength λ4may be selected from the wavelength range of λp,4 ± 10 nm, such as selected from the wavelength range of λp,4 ± 5 nm, like selected from the wavelength range of λp,4± 2 nm, more especially selected from the wavelength range of λp,4 ± 1 nm. In embodiments, (λ2-λ1)≥10 nm, such as (λ2-λ1)≥20 nm, like (λ2-λ1)≥30 nm. In further embodiments, (λ2-λ1)≥40 nm, such as (λ2-λ1)≥50 nm (though smaller values may thus also be possible). In further embodiments, (λ3-λ2)≥10 nm, such as (λ3-λ2)≥20 nm, like (λ3- λ2)≥30 nm. In further embodiments, (λ3-λ2)≥40 nm, such as (λ3-λ2)≥50 nm (though smaller values may thus also be possible). In further embodiments, (λ4-λ3)≥10 nm, such as (λ4-λ3)≥20 nm, like (λ4-λ3)≥30 nm. In further embodiments, (λ4-λ3)≥40 nm, such as (λ4-λ3)≥50 nm (though smaller values may thus also be possible). Yet, in specific embodiments the first light source may comprise a laser diode, the second light source may comprise a laser diode, the third light source may comprise a laser diode, and the fourth light source may comprise a laser diode. In specific embodiments, however, the second peak wavelength λp,2 may be selected from the wavelength range of 500-540 nm, the third peak wavelength λp,3may be selected from the wavelength range of 540-600 nm, and wherein the fourth peak wavelength λp,4may be selected from the wavelength range of 600-670 nm. The diffused first light source light, the diffused second light source light, the diffused third light source light, and the diffused fourth light source light may be combined by one or more dichroic beam combiner (see also above where the dichroic beam splitter is described). Hence, in embodiments the light generating system may comprise dichroic-based combiners (1710,1720...), configured to (a) combine the diffused first light source light, diffused second light source light, diffused third light source light, and diffused fourth light source light, and (b) direct the combined diffused first light source light, diffused second light 2024PF80180 36 source light, diffused third light source light, diffused fourth light source light in an optical path to the light exit. Especially, in embodiments none of the first light source light, the second light source light, the optional third light source light, and the optional fourth light source light may escape from the light exit without first propagating via the reflective polarization maintaining diffuser. The first light source, the second light source, the optional third light source, and the optional fourth light source may provide with relatively narrow band widths. Dependent upon the choice of emission wavelengths of these light sources, it may e.g. be possible to provide white system light (see also below) with a relatively good color rendering index. However, it may also be possible to provide white light with at least the first light source light and the second light source light, and emission (or “luminescent material light”) of a luminescent material. The luminescent material may be excited via several options, which may optionally also be combined. In first options, part of the light source light of one of the types of light sources may be redirected to the luminescent material. This may be before the light source light is introduced in the optical path between the first light source and the reflective polarization maintaining diffuser, whereby effectively less light source light of that light source (or those light sources) is diffused. However, this may also be after the diffused light source light is redirected from the optical path between the first light source and the reflective polarization maintaining diffuser into an optical path to the light exit. This would imply that the luminescent material may be excited with diffused light source light. In second options, an additional light source is used. This can be a same type of light source as used for the light sources for creating diffused light source light as described herein, but is may also be a different type. With an additional light source, individual control of the excitation power, and thus the spectral power of the luminescent material light may be easier. Hence, in embodiments the light generating system may further comprise a luminescent material (and optics), wherein the light generating system comprises a source of excitation light, wherein the luminescent material is configured to convert at least part of the excitation light into luminescent material light. In embodiments, the optics may be configured to direct the luminescent material light in an optical path to the light exit. In specific embodiments, the light generating system may be configured to generate in an 2024PF80180 37 operational mode of the light generating system light (further) comprising the luminescent material light. Hence, in operational modes the system light may only comprise luminescent material light and in other operational modes the system light may comprise one or more of (a) diffused first light source light, diffused second light source light, optional diffused third light source light, and optional diffused fourth light source light, and (b) luminescent material light. In yet other operational modes the system light may comprise one or more of diffused first light source light, diffused second light source light, optional diffused third light source light, and optional diffused fourth light source light. 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 down-conversion. In specific embodiments, however the second radiation has a spectral power distribution with intensity at smaller wavelengths than the first radiation, which is the case in the so-called up-conversion. 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 (λex<λem), 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 (λex>λem). 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. 2024PF80180 38 The term “luminescent 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. 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. In specific embodiments the luminescent material comprises a luminescent material of the type A3B5O12: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 (Y1-xLux)3B5O12: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 (Y1-xLux)3Al5O12: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%, 2024PF80180 39 especially 0.1 to 2% (relative to A). Ce and 10% Y, the full correct formula could be (Y0.1Lu0.89Ce0.01)3Al5O12. Ce in garnets is substantially or only in the trivalent state, as is known to the person skilled in the art. Alternatively or additionally, the luminescent material may comprise a luminescent material of the type A3Si6N11:Ce3+, wherein A comprises one or more of Y, La, Gd, Tb and Lu, such as in embodiments one or more of La and Y. In embodiments, the luminescent material may alternatively or additionally comprise one or more of MS:Eu2+and / or M2Si5N8:Eu2+and / or MAlSiN3:Eu2+and / or Ca2AlSi3O2N5: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)2Si5N8: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 CaAlSiN3:Eu, the correct formula could be (Ca0.98Eu0.02)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)2Si5N8:Eu can also be indicated as M2Si5N8: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 Ba1.5Sr0.5Si5N8: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 MAlSiN3: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 2024PF80180 40 more of Ba, Sr, and Ca). Eu in the above luminescent materials is substantially or only in the divalent state, as is known to the person skilled in the art. 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)2Si5N8: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 CaAlSiN3:Eu, the correct formula could be (Ca0.98Eu0.02)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)2Si5N8:Eu can also be indicated as M2Si5N8: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 Ba1.5Sr0.5Si5N8: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 MAlSiN3: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). In embodiments, the luminescent material may comprise a luminescent material of the type M1−xLi3−2yAl1+2y−zSizO4−4y−zN4y+z:Eux. Herein, M may comprise one or more of magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba), such as especially one or more of Ca, Sr, and Ba. Hence, M1−xLi3−2yAl1+2y−zSizO4−4y−zN4y+z:Eux may especially refer to (Mg,Ca,Sr,Ba)1−xLi3−2yAl1+2y−zSizO4−4y−zN4y+z:Eux. Such a luminescent material may 2024PF80180 41 be indicated as an SLA-type phosphor, or Luminescent materials of the type M1−xLi3−2yAl1+2y−zSizO4−4y−zN4y+z:Eux may be described in US2021171827A1, which is hereby herein incorporated by reference. In M1−xLi3−2yAl1+2y−zSizO4−4y−zN4y+z:Eux, x may be selected from the range of 0 < x ≤ 0.1, such as from the range of 0.0005 < x ≤ 0.08, especially from the range of 0.001 < x ≤ 0.05. Hence, europium (Eu) may not replace more than 10% of the cation M, and may substantially or only be in the divalent state (Eu2+), as is known to the person skilled in the art. Further, in M1−xLi3−2yAl1+2y−zSizO4−4y−zN4y+z:Eux, y may be selected from the range of 0 ≤ y ≤ 1, such as from the range of 0 ≤ y ≤ 0.75, especially from the range of 0 ≤ y ≤ 0.6. In specific embodiments, y = 0. In M1−xLi3−2yAl1+2y−zSizO4−4y−zN4y+z:Eux, z may be selected from the range of 0 ≤ z ≤ 0.1, such as from the range of 0 ≤ z ≤ 0.07, especially from the range of 0 ≤ z ≤ 0.05. Hence, in embodiments, in an SLA phosphor, SiN may replace AlO to a maximum of 10 mole%. In embodiments, an SLA phosphor may crystallize in a UCr4C4type crystal structure. Hence, the luminescent material may comprise a luminescent material of the type M1−xLi3−2yAl1+2y−zSizO4−4y−zN4y+z:Eux, wherein M comprises one or more of Ca, Sr, and Ba, wherein 0 < x ≤ 0.04, wherein 0 ≤ y ≤ 1, wherein 0 ≤ z ≤ 0.05, and wherein y + z ≤ 1. Further, the luminescent material may comprise a SiAlON phosphor, such as selected from the group comprising (a) Si12–m–nAlm+nOnN16–n:Eu2+(α-SiAlON), (b) Si6–nAlnOnN8–n:Eu2+, wherein 0 ≤ n ≤ 4.2 (β-SiAlON), and (c) Si2–nAlnO1+nN2–n:Eu2+, wherein 0 ≤ n ≤ 0.2 (O-SiAlON). 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. In embodiments, the luminescent material may comprise a luminescent material of the type M’xM2-2xAX6doped with tetravalent manganese, wherein M’ comprises an alkaline earth cation, M comprises an alkaline cation, and x is in the range of 0-1, wherein A comprises a tetravalent cation, for instance comprising one or more of silicon and titanium, wherein X comprises a monovalent anion, at least comprising fluorine. A luminescent material of the type M’xM2-2xAX6doped with tetravalent manganese is amongst others described in WO2013121355A1, which is herein incorporated by reference. Passages from WO2013121355A1 are also copied herein. Herein, M’xM2-2xAX6 doped with tetravalent manganese, may further also shortly be indicated as “phosphor”, i.e. the phrase " phosphor comprising M’xM2-2xAX6doped with tetravalent manganese" may in an embodiment also be read as M’xM2-2xAX6 2024PF80180 42 doped with tetravalent manganese phosphor, (tetravalent) Mn-doped M’xM2-2xAX6 phosphor, or shortly "phosphor". Relevant alkaline cations (M) are sodium (Na), potassium (K) and rubidium (Rb). Optionally, also lithium and / or cesium may be applied. In a preferred embodiment, M comprises at least potassium. In yet another embodiment, M comprises at least rubidium. The phrase “wherein M comprises at least potassium” indicates for instance that of all M cations in a mole M’xM2-2xAX6, a fraction comprises K+and an optionally remaining fraction comprises one or more other monovalent (alkaline) cations (see also below). In another preferred embodiment, M comprises at least potassium and rubidium. Optionally, the M’xM2-2xAX6 luminescent material has the hexagonal phase. In yet another embodiment, the M’xM2-2xAX6luminescent material has the cubic phase. Relevant alkaline earth cations (M’) are magnesium (Mg), strontium (Sr), calcium (Ca) and barium (Ba), especially one or more of Sr and Ba. In an embodiment, a combination of different alkaline cations may be applied. In yet another embodiment, a combination of different alkaline earth cations may be applied. In yet another embodiment, a combination of one or more alkaline cations and one or more alkaline earth cations may be applied. For instance, KRb0.5Sr0.25AX6might be applied. As indicated above, x may be in the range of 0-1, especially x<1. In an embodiment, x=0. The term “tetravalent manganese” refers to Mn4+. This is a well-known luminescent ion. In the formula as indicated above, part of the tetravalent cation A (such as Si) is being replaced by manganese. Hence, M’xM2-2xAX6 doped with tetravalent manganese may also be indicated as M’xM2-2xA1-mMnmX6. The mole percentage of manganese, i.e. the percentage it replaces the tetravalent cation A will in general be in the range of 0.1-15 %, especially 1-12 %, i.e. m is in the range of 0.001-0.15, especially in the range of 0.01-0.12. A comprises a tetravalent cation, and preferably at least comprises silicon. A may optionally (further) comprise one or more of titanium (Ti), germanium (Ge), stannum (Sn) and zinc (Zn). Preferably, at least 80%, even more preferably at least 90%, such as at least 95% of M consists of silicon. Hence, in a specific embodiment, M’xM2-2xAX6may also be described as M’xM2-2xA1-m-t-g-s-zrMnmTitGegSnsZrzrX6, wherein m and x are as indicated above, and wherein t,g,s,zr are each individually preferably in the range of 0-0.2, especially 0-0.1, even more especially 0-0.05, wherein t+g+s+zr is smaller than 1, especially equal to or smaller than 0.2, preferably in the range of 0-0.2, especially 0-0.1, even more especially 0- 0.05, and wherein A is especially Si. X is preferably fluorine (F). 2024PF80180 43 As indicated above, M relates cations, but preferably at least comprises potassium and / or rubidium. Other monovalent cations that may further be comprised by M can be selected from the group consisting of lithium (Li), sodium (Na), cesium (Cs) and ammonium (NH4+). In an embodiment, preferably at least 80%(i.e.80% of all moles of the type M), even more preferably at least 90%, such as 95% of M consists of potassium and / or rubidium. Especially, in these embodiments x is thus zero. Hence, when M (or A) in chemical formulas refer to n different elements, this may imply that the relevant formula may comprise for the M (or A) position in the formula essentially any permutation of the n different elements. For instance, when M=Ba,Sr,Ca or when M comprises one or more of Ba,Sr,Ca or when M refers to Ba,Sr,Ca, i.e. n=3, this may imply that in the formula Ba, Sr, Ca, (BaxSry), (BaxCay), (CaxSry), or (BaxSryCaz), may be available, wherein in general x+y+z=1. Referring to e.g. M’xM2-2xAX6, this may refer to e.g. one or more of K2SiF6:Mn4+and of Rb2SiF6:Mn4+, or (KxRby)2SiF6:Mn4+, etc. Referring to (Ba,Sr,Ca)AlSiN3:Eu, this may imply BaAlSiN3:Eu, SrAlSiN3:Eu, CaAlSiN3:Eu, (BaxSry)AlSiN3:Eu, (BaxCay)AlSiN3:Eu, (CaxSry)AlSiN3:Eu, or (BaxSryCaz)AlSiN3:Eu. Referring to e.g. A3B5O12:Ce, wherein A in embodiments comprises one or more of Y, La, Gd, Tb and Lu, this may imply Y3B5O12:Ce, La3B5O12:Ce, GdB5O12:Ce, Tb3B5O12:Ce, Lu3B5O12:Ce, but also e.g. (Yx,Gdy)3B5O12:Ce, (Yx,Luy)3B5O12:Ce, (Gdx,Luy)3B5O12:Ce, (Yx,Gdy,Luz)3B5O12:Ce, etc. etc., with hereby only limiting for the sake of economy to unary, binary, and ternary examples, though quaternary and higher examples are not excluded herein. Further, indications like “K,Rb” or Ba,Sr,Ca, and similar indications (see also above), may indicate one or more of such elements. Hence, (K,Rb)2SiF6:Mn4+, may e.g. refer to K2SiF6:Mn4+and of Rb2SiF6:Mn4+, or (KxRby)2SiF6:Mn4+. Also herein in general x+y=1. Hence, when M (or A) may refer to n different elements, with n being at least two, 2n-1 permutations may in principle be possible. Alternatively or additionally, also other luminescent materials may be applied. For instance quantum structures, such as 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. Different luminescent materials may have different spectral power distributions of the respective luminescent material light. Alternatively or additionally, such 2024PF80180 44 different luminescent materials may different color points (or dominant wavelengths). Hence, in embodiments the luminescent material may comprise a luminescent material of the type A3B5O12: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. As indicated above, the system may comprise optics. The term “optics” may especially refer to (one or more) optical elements. Hence, the terms “optics” and “optical elements” may refer to the same items. The optics may include one or more or mirrors, reflectors, collimators, lenses, prisms, diffusers, phase plates, polarizers, diffractive elements, gratings, dichroics, arrays of one or more of the afore-mentioned, etc. Alternatively or additionally, the term “optics” may refer to a holographic element or a mixing rod. In embodiments, the optics may include one or more of beam expander optics and zoom lens optics. See further above for examples of optics. In embodiments, the optics may comprise an integrator, like a “Koehler integrator” (or “Köhler integrator”). The quarter wave plates, the polarization based beam directors, the dichroic based beam directors, etc., described herein, may also be comprised by the term “optics”. The phrase “direct light in an optical path to the light exit”, and similar phrases, may imply that one or more optical elements are configured to guide the light along the optical to the light exit. As indicated above, the system may comprise a control system. Especially, the control system may be configured to control a spectral power distribution of the system light by (individually) controlling the light sources. In embodiments, the system light may be white light. In specific embodiments, in an operational mode of the light generating system, the system light may have a color rendering index of at least 65 and a correlated color temperature selected from the range of 2000-12000 K. 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 2024PF80180 45 (black body locus), especially within about 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. In embodiments, one or more of the light sources may comprise a laser bank. For instance, the first light source may comprise a laser bank comprising a plurality of diode lasers and / or the second light source may comprise a laser bank comprising a plurality of diode lasers, etc. 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 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. 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 2024PF80180 46 may especially refer to a wavelength selected 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. 2024PF80180 47 In yet a further aspect, the 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 vehicle lighting 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 light sources, optics, etc. BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which: Figs.1-3 schematically depict some embodiments; and Fig.4 schematically depict some application embodiments. The schematic drawings are not necessarily to scale. DETAILED DESCRIPTION OF THE EMBODIMENTS Referring to Figs.1-3, in specific embodiments, the invention provides a light generating system 1000 comprising a first light source 10, a first quarter wave plate 721, a first polarization based beam director 1510, a reflective polarization maintaining diffuser 710, a first additional light source arrangement 1120, and a light exit 1090. Furthermore, in embodiments, the first light source 10 may be configured to generate first light source light 11, having a first wavelength λ1. Especially, the first light source 10 may be selected from the group comprising laser diodes, superluminescent diodes, and stacked multi-junction light- 2024PF80180 48 emitting diodes. Furthermore, in first quarter wave plate 721 may be configured in an optical path between the first light source 10 and the reflective polarization maintaining diffuser 710; the first quarter wave plate 721 may be a quarter wave plate for λ1. Furthermore, in embodiments, the first quarter wave plate 721 together with the reflective polarization maintaining diffuser 710 may be configured to (a) convert light comprising s- polarization into light comprising p-polarization, or (b) convert light comprising p- polarization into light comprising s-polarization. Especially, the first polarization based beam director 1510 may be configured in an optical path between the first light source 10 and the reflective polarization maintaining diffuser 710; the first polarization based beam director 1510 may be configured upstream of the first quarter wave plate 721; the light generating system 1000 may be configured such that the first light source light 11 received by the first polarization based beam director 1510 may comprise linear polarized light. Moreover, in embodiments, the first polarization based beam director 1510 may be configured to direct first light source light 11 having a first linear polarization, received by the first polarization based beam director 1510, in an optical path to the reflective polarization maintaining diffuser 710. Yet, in embodiments, the reflective polarization maintaining diffuser 710 may be configured to diffuse at least part of the first light source light 11 received by the reflective polarization maintaining diffuser 710 into diffused first light source light 11d (while maintaining at least part of (the polarization type (but changing the handedness)) of the polarization). Further, in embodiments, the first polarization based beam director 1510 may be (further) configured to direct diffused first light source light 11d having a second linear polarization, received by the first polarization based beam director 1510, in an optical path to the light exit 1090. Moreover, in embodiments, the first linear polarization and the second linear polarization may be selected from s-polarization and p-polarization. Especially, the first additional light source arrangement 1120 may comprise a second light source 20, a first dichroic based beam director 1620, a second quarter wave plate 722, and a second polarization based beam director 1520. Especially, the second light source 20 may be configured to generate second light source light 21, having a second wavelength λ2. Yet, in embodiments, |λ2-λ1|≥30 nm. Furthermore, in embodiments, the second light source 20 may be selected from the group comprising laser diodes, superluminescent diodes, and stacked multi-junction light-emitting diodes. In further embodiments, the first dichroic based beam director 1620 may be configured upstream of the first polarization based beam director 1510; the first dichroic based beam director 1620 may be configured to direct first light source light 11 and second light source light 21, received by the first dichroic based beam director 1620 2024PF80180 49 in an optical path to the polarization diffuser 710. Furthermore, in embodiments, the second quarter wave plate 722 may be configured downstream of the first dichroic based beam director 1620 and downstream of the second polarization based beam director 1520 and upstream of the first polarization based beam director 1510; the second quarter wave plate 722 may be configured in an optical path between the second light source 20 and the reflective polarization maintaining diffuser 710; the second quarter wave plate 722 may be a quarter wave plate for |λ2-λ1|. Furthermore, in embodiments, the second polarization based beam director 1520 may be configured in an optical path between the second light source 20 and the reflective polarization maintaining diffuser 710; the second polarization based beam director 1520 may be configured downstream of the first dichroic based beam director 1620 and upstream of the second quarter wave plate 722; the light generating system 1000 may be configured such that the second light source light 21 received by the second polarization based beam director 1520 may comprise linear polarized light; the second polarization based beam director 1520 may be configured to direct second light source light 21 (and first light source light 11) having a first linear polarization, received by the second polarization based beam director 1520, in an optical path to the reflective polarization maintaining diffuser 710. Further, in embodiments, the reflective polarization maintaining diffuser 710 may be (also) configured to diffuse at least part of the second light source light 21 received by the reflective polarization maintaining diffuser 710 into diffused second light source light 21d (while maintaining at least part of (the polarization type (but changing the handedness)) of the polarization). Further, in embodiments, the second polarization based beam director 1520 may be (further) configured to direct diffused second light source light 21d having a second linear polarization, received by the second polarization based beam director 1520, in an optical path to the light exit 1090. Especially, the light generating system 1000 may be configured to generate in an operational mode of the light generating system 1000 system light 1001 comprising diffused first light source light 11d and diffused second light source light 21d. Reference R refers to a (specular) reflector. Reference O refers to one or more optical elements, like e.g. one or more lenses. In embodiments, the first light source 10 may be configured to generate first light source light 11 having a first peak wavelength λp,1 selected from the wavelength range of 430-490 nm. Further, in embodiments, the first wavelength λ1may be selected from the wavelength range of λp,1 ± 10 nm. Especially, the second light source 20 may be configured to generate second light source light 21 having a second peak wavelength λp,2selected from 2024PF80180 50 the wavelength range of 430-680 nm. embodiments, |λp,2-λp,1|≥30 nm. Further, in embodiments, the second wavelength λ2 may be selected from the wavelength range of λp,2 ± 10 nm. Further, in embodiments, the first light source 10 may comprise a laser diode Especially, the second light source 20 may comprise a laser diode. In further embodiments, the light generating system 1000 may comprise a first dichroic-based combiner 1710, configured to (a) combine the diffused first light source light 11d and diffused second light source light 21d, and (b) direct the combined diffused first light source light 11d and diffused second light source light 21d in an optical path to the light exit 1090. Referring to Figs.1-2, in further embodiments, the light generating system 1000 may further comprise a second additional light source arrangement 1130. Especially, the second additional light source arrangement 1130 may comprise a third light source 30, a second dichroic based beam director 1630, a third quarter wave plate 723, and a third polarization based beam director 1530. Especially, the third light source 30 may be configured to generate third light source light 31, having a third wavelength λ3. Especially, |λ3-λ2|≥30 nm. In further embodiments, |λ3-λ1|≥30 nm. In further embodiments, the third light source 30 may be selected from the group comprising laser diodes, superluminescent diodes, and stacked multi-junction light-emitting diodes. Further, in embodiments, the second dichroic based beam director 1630 may be configured upstream of the second polarization based beam director 1520; the second dichroic based beam director 1630 may be configured to direct first light source light 11 and third light source light 31, received by the second dichroic based beam director 1630, in an optical path to the polarization maintaining diffuser 710. Furthermore, in embodiments, the third quarter wave plate 723 may be configured downstream of the second dichroic based beam director 1630 and downstream of the third polarization based beam director 1530 and upstream of the second polarization based beam director 1520; the third quarter wave plate 723 may be configured in an optical path between the third light source 30 and the reflective polarization maintaining diffuser 710; the third quarter wave plate 723 may be a quarter wave plate for |λ3-λ2|. Especially, the third polarization based beam director 1530 may be configured in an optical path between the third light source 30 and the reflective polarization maintaining diffuser 710; the third polarization based beam director 1530 may be configured downstream of the second dichroic based beam director 1630 and upstream of the third quarter wave plate 723; the light generating system 1000 may be configured such that the third light source light 31 received by the third polarization based beam director 1530 may comprise linear polarized light; the third 2024PF80180 51 polarization based beam director 1530 may to direct third light source light 31 (and first light source light 11) having a first linear polarization, received by the third polarization based beam director 1530, in an optical path to the reflective polarization maintaining diffuser 710. Especially, the reflective polarization maintaining diffuser 710 may be (also) configured to diffuse at least part of the third light source light 31 received by the reflective polarization maintaining diffuser 710 into diffused third light source light 31d (while maintaining at least part of (the polarization type (but changing the handedness)) of the polarization). In further embodiments, the third polarization based beam director 1530 may be (further) configured to direct diffused third light source light 31d having a second linear polarization, received by the third polarization based beam director 1530, in an optical path to the light exit 1090. Further, in embodiments, the light generating system 1000 may be configured to generate in an operational mode of the light generating system 1000 system light 1001 comprising diffused first light source light 11d, diffused second light source light 21d, and diffused third light source light 31d. Moreover, in embodiments, the first light source 10 may be configured to generate first light source light 11 having a first peak wavelength λp,1 selected from the wavelength range of 430-490 nm. In further embodiments, the first wavelength λ1may be selected from the wavelength range of λp,1 ± 10 nm. In further embodiments, the second light source 20 may be configured to generate second light source light 21 having a second peak wavelength λp,2 selected from the wavelength range of 430-680 nm. Yet, in embodiments, |λp,2-λp,1|≥30 nm. Further, in embodiments, the second wavelength λ2 may be selected from the wavelength range of λp,2± 10 nm. Further, in embodiments, the third light source 30 may be configured to generate third light source light 31 having a third peak wavelength λp,3 selected from the wavelength range of 430-680 nm. Furthermore, in embodiments, |λp,3- λp,2|≥30 nm. Moreover, in embodiments, the third wavelength λ3 may be selected from the wavelength range of λp,3± 10 nm. Further, in embodiments, the second peak wavelength λp,2 may be selected from the wavelength range of 490-590 nm. Furthermore, in embodiments, the third peak wavelength λp,3 may be selected from the wavelength range of 590-680 nm. Especially, the first light source 10 may comprise a laser diode. Especially, the second light source 20 may comprise a laser diode. Further, in embodiments, third light source 30 may comprise a laser diode. In further embodiments, the light generating system 1000 may comprise dichroic-based combiners (1710,1720.), configured to (a) combine the diffused first light source light 11d, diffused second light source light 21d, and diffused third 2024PF80180 52 light source light 31d, and (b) direct the diffused first light source light 11d, diffused second light source light 21d, and diffused third light source light 31d in an optical path to the light exit 1090. Referring to Fig.2, in embodiments, the light generating system 1000 may further comprise a third additional light source arrangement 1140. Especially, the third additional light source arrangement 1140 may comprise a fourth light source 40, a third dichroic based beam director 1640, a fourth quarter wave plate 724, and a fourth polarization based beam director 1540. Yet, in embodiments, the fourth light source 40 may be configured to generate fourth light source light 41, having a fourth wavelength λ4. Further, in embodiments, |λ4>λ3|≥30 nm, and |λ4>λ2|≥30 nm, and |λ4>λ1|≥30 nm. Especially, the fourth light source 40 may be selected from the group comprising laser diodes, superluminescent diodes, and stacked multi-junction light-emitting diodes. Moreover, in embodiments, the third dichroic based beam director 1640 may be configured upstream of the third polarization based beam director 1530; the third dichroic based beam director 1640 may be configured to direct first light source light 11 and fourth light source light 41, received by the third dichroic based beam director 1640 in an optical path to the polarization maintaining diffuser 710. Furthermore, in embodiments, the fourth quarter wave plate 724 may be configured downstream of the third dichroic based beam director 1640 and downstream of the fourth polarization based beam director 1540 and upstream of the third polarization based beam director 1530; the fourth quarter wave plate 724 may be configured in an optical path between the fourth light source 40 and the reflective polarization maintaining diffuser 710; the fourth quarter wave plate 724 may be a quarter wave plate for |λ4-λ3|. Furthermore, in embodiments, the fourth polarization based beam director 1540 may be configured in an optical path between the fourth light source 40 and the reflective polarization maintaining diffuser 710; the fourth polarization based beam director 1540 may be configured downstream of the third dichroic based beam director 1640 and upstream of the fourth quarter wave plate 724; the light generating system 1000 may be configured such that the fourth light source light 41 received by the fourth polarization based beam director 1540 may comprise linear polarized light; the fourth polarization based beam director 1540 may be configured to direct fourth light source light 41 (and first light source light 11) having a first linear polarization, received by the fourth polarization based beam director 1540, in an optical path to the reflective polarization maintaining diffuser 710. Further, in embodiments, the reflective polarization maintaining diffuser 710 may be (also) configured to diffuse at least part of the fourth light source light 41 received by the reflective polarization 2024PF80180 53 maintaining diffuser 710 into diffused fourth source light 41d (while maintaining at least part of (the polarization type (but changing the handedness)) of the polarization). Further, in embodiments, the fourth polarization based beam director 1540 may be (further) configured to direct diffused fourth light source light 41d having a second linear polarization, received by the fourth polarization based beam director 1540, in an optical path to the light exit 1090. Especially, the light generating system 1000 may be configured to generate in an operational mode of the light generating system 1000 system light 1001 comprising diffused first light source light 11d, diffused second light source light 21d, diffused third light source light 31d, and diffused fourth light source light 41d. In further embodiments, the fourth light source 40 may be configured to generate fourth light source light 41 having a fourth peak wavelength λp,4selected from the wavelength range of 430-680 nm. Yet, in embodiments, |λp,4-λp,3|≥30 nm. Especially, the fourth wavelength λ4may be selected from the wavelength range of λp,4± 10 nm. Further, in embodiments, the second peak wavelength λp,2 may be selected from the wavelength range of 500-540 nm, the third peak wavelength λp,3may be selected from the wavelength range of 540-600 nm. Especially, the fourth peak wavelength λp,4 may be selected from the wavelength range of 600-670 nm. Further, in embodiments, the light generating system 1000 may comprise dichroic-based combiners 1710,1720..., configured to (a) combine the diffused first light source light 11d, diffused second light source light 21d, diffused third light source light 31d, and diffused fourth light source light 41d, and (b) direct the combined diffused first light source light 11d, diffused second light source light 21d, diffused third light source light 31d, and diffused fourth light source light 41d in an optical path to the light exit 1090. Referring to Fig.3, in further embodiments, the light generating system 1000 may further comprise a luminescent material 200 and optics 500. In further embodiments, the light generating system 1000 may comprise a source of excitation light 1. Especially, the luminescent material 200 may be configured to convert at least part of the excitation light 1 into luminescent material light 201. Especially, the optics 500 may be configured to direct the luminescent material light 201 in an optical path to the light exit 1090. Furthermore, in embodiments, the light generating system 1000 may be configured to generate in an operational mode of the light generating system 1000 system light 1001 may further comprise the luminescent material light 201. Optics 500, including one or more reflectors R and one or more dichroic-based combiners, may (also) be applied to combine the different types of diffused light. In this way, 2024PF80180 54 system light 1001 may be provided light selected from one or more of first diffused light source light 11d, diffused second light source light 21d, diffused third light source light 31d, and diffused fourth light source light 41d. Reference HS refers to a thermally conductive material, like (provided by) a heat sink. Especially, the luminescent material 200 may comprise a luminescent material of the type A3B5O12:Ce. Especially, A may comprise one or more of Y, La, Gd, Tb and Lu. In further embodiments, B may comprise one or more of Al, Ga, In and Sc. Note that the luminescent material embodiment schematically depicted in Fig. 3 may also be applied in the embodiments of Fig.1 and 2. Further, the embodiments of Fig.3 may also be applied without the luminescent material (and additional light source 1010). Further, instead of using an additional light source, or in addition thereto, light of one of the light sources may be redirected to the luminescent material. Referring to Figs.1-3, in embodiments, the light generating system 1000 may further comprise a control system 300. Especially, in embodiments, the control system 300 may be configured to control a spectral power distribution of the system light 1001 by individually controlling the light sources 10,20,... In further embodiments, in an operational mode of the light generating system 1000, the system light 1001 may have a color rendering index of at least 65 and a correlated color temperature selected from the range of 2000-12000 K. Further, in embodiments, one or more of the light sources 10,20,.. may comprise a laser bank. In embodiments, one or more of the following may apply: (i) a first laser bank may comprise a plurality of first light sources, (ii) a second laser bank may comprise a plurality of second light sources, (iii) a third laser bank may comprise a plurality of third light sources, and (iv) a fourth laser bank may comprise a plurality of fourth light sources. Referring to e.g. the embodiments of Figs.1-3, but this may also apply to other embodiments one or more of the following may apply: (a) in embodiments between the first polarization based beam director 1510 and the reflective polarization maintaining diffuser 710: the first light source light 11 and the second light source light 21 may propagate colinear; and the diffused first light source light 11d and the diffused second light source light 21d may propagate colinear, (b) in embodiments between the first polarization based beam director 1510 and the reflective polarization maintaining diffuser 710: the first light source light 11, the second light source light 21, and the third light source light 31 may 2024PF80180 55 propagate colinear; and the diffused first light 11d, the diffused second light source light 21d, and the diffused third light source light 31d may propagate colinear, (c) in embodiments between the first polarization based beam director 1510 and the reflective polarization maintaining diffuser 710: the first light source light 11, the second light source light 21, the third light source light 31, and the fourth light source light 41 may propagate colinear; and the diffused first light source light 11d, the diffused second light source light 21d, the diffused third light source light 31d, and the fourth light source light 41 may propagate colinear. Further, one or more of the following may apply: (d) in embodiments between the second polarization based beam director 1520 and the reflective polarization maintaining diffuser 710: the first light source light 11, the second light source light 21, and the third light source light 31, may propagate colinear; and the diffused second light source light 21d, and the diffused third light source light 31d, may propagate colinear, and (e) in embodiments between the third polarization based beam director 1530 and the reflective polarization maintaining diffuser 710: the first light source light 11, the third light source light 31, and the fourth light source light 41, may propagate colinear; and the diffused third light source light 31d and the diffused fourth light source light 41d, may propagate colinear. Referring to Figs.1-3 the optical elements schematically depicted in the optical path between the first light source 10 and the reflective polarization maintaining diffuser 710 are configured such that an optical element right of another optical element is configured downstream of that other optical element, and an optical element left of another optical element, is configured upstream of that other optical element. Especially, herein for all optical element in the optical path between the first light source 10 and the reflective polarization maintaining diffuser 710, “downstream” and “upstream” relate to position of optical elements relative the propagation of light of a light source to the reflective polarization maintaining diffuser 710, especially of the first light source light 11 from the first light source 10 to the reflective polarization maintaining diffuser 710. Referring to Figs 1-3, Fig.3 schematically depicts an embodiment of the system 1000 comprising a single additional light source arrangement, i.e. first additional light source arrangement 1120, Fig.1 schematically depicts an embodiment of the system 1000 comprising two additional light source arrangement, i.e. first additional light source arrangement 1120, and second additional light source arrangement 1130, and Fig.2 schematically depicts an embodiment of the system 1000 comprising three additional light source arrangement, i.e. first additional light source arrangement 1120, and second additional light source arrangement 1130, and third first additional light source arrangement 1140. 2024PF80180 56 Hence, Fig.2 schematically an embodiment with the most stages. Using this schematically depicted embodiment to further explain the other embodiments, the following is noted, for the sake of argument assuming the light sources provide s-polarized light: - s-polarized light propagating from the first light source 10 from which the light originates to the reflective polarization maintaining diffuser 710 (i.e. propagating to the right in the schematic drawing) is s-polarized upstream of the first quarter wave plate 721, and is converted such that after reflection (and diffusion) at the reflective polarization maintaining diffuser 710, the light returns (i.e. propagating to the left in the schematic drawing), and after passing the first quarter wave plate 721 in opposite direction, it is p- polarized. Similarly, p-polarized light can be converted into s-polarized light; - s-polarized light propagating from the second light source 20 from which the light originates to the reflective polarization maintaining diffuser 710 (i.e. propagating to the right in the schematic drawing) is s-polarized upstream of the second quarter wave plate 722, and is converted such that after reflection (and diffusion) at the reflective polarization maintaining diffuser 710, the light returns (i.e. propagating to the left in the schematic drawing), and after passing the second quarter wave plate 722 in opposite direction, it is p- polarized. Similarly, p-polarized light can be converted into s-polarized light; - s-polarized light propagating from the third light source 30 from which the light originates to the reflective polarization maintaining diffuser 710 (i.e. propagating to the right in the schematic drawing) is s-polarized upstream of the third quarter wave plate 723, and is converted such that after reflection (and diffusion) at the reflective polarization maintaining diffuser 710, the light returns (i.e. propagating to the left in the schematic drawing), and after passing the third quarter wave plate 723 in opposite direction, it is p- polarized. Similarly, p-polarized light can be converted into s-polarized light; and - s-polarized light propagating from the fourth light source 40 from which the light originates to the reflective polarization maintaining diffuser 710 (i.e. propagating to the right in the schematic drawing) is s-polarized upstream of the fourth quarter wave plate 724, and is converted such that after reflection (and diffusion) at the reflective polarization maintaining diffuser 710, the light returns (i.e. propagating to the left in the schematic drawing), and after passing the fourth quarter wave plate (724) in opposite direction, it is p- polarized. Similarly, p-polarized light can be converted into s-polarized light. Of course, the light sources may also provide p-polarized light, and then the p- polarized light is converted into diffused s-polarized light. 2024PF80180 57 Here below, some examples based on three or four light sources, respectively: ^^^ ^^^ ^^^ ^^^^^ ^^^^^^^^^^^ ^^^^^^^^^^^440 560 640 110 30 20 450 580 640 112.5 32.5 15 460 560 630 115 25 17.5 ^1 ^^^ ^^^ ^^^ ^^^^^ ^^^^^^^^^^^ ^^^^^^^^^^^ ^^^^^^^^^^^450 560 610 640 112.5 12.5 7.5 7.5 460 560 600 650 115 10 12.5 12.5 The values in the tables are in nanometers. The peak wavelengths of the light sources may e.g. the wavelengths indicated in the tables. For example, for first light source light with λ1= 440 nm, second light source light with λ2 = 560 nm and third light source light with λ3 = 640 nm, the following applies. The first quarter wave plate that is made of quartz, as an example, has a birefringence of 0.0094 and a thickness of 12 micron. The second quarter wave plate and the third quarter wave plate, respectively, that are both made of quartz as an example, have a thickness of 3.5 micron and 2.4 micron, respectively. With the current invention, e.g. RGB, RGB-amber, or RB-yellow phosphor solutions may be provided. Fig.4 schematically depicts an embodiment of a luminaire 2 comprising the light generating system 1000 as described above. Reference 301 indicates a user interface which may be functionally coupled with the control system 300 comprised by or functionally coupled to the light generating system 1000. Fig.3 also schematically depicts an embodiment of lamp 1 comprising the light generating system 1000. Reference 3 indicates a projector device or projector system, which may be used to project images, such as at a wall, which may also comprise the light generating system 1000. Hence, Fig.3 schematically depicts embodiments of a lighting device 1200 selected from the group of a lamp 1, a luminaire 2, a projector device 3, a disinfection device, a photochemical reactor, and an optical wireless communication device, comprising the light generating system 1000 as described herein. In embodiments, such lighting device may be a lamp 1, a luminaire 2, a projector device 3, a disinfection device, a vehicle lighting device, or an optical wireless communication device. Lighting device light escaping from the lighting device 1200 is indicated with reference 2024PF80180 58 1201. Lighting device light 1201 may consist of system light 1001, and may in specific embodiments thus be system light 1001. Reference 1300 refers to a space, such as a room. Reference 1305 refers to a floor and reference 1310 to a ceiling; reference 1307 refers to a wall. Fig.4 also schematically depicts an embodiments of an outdoor light, or stage light, or stadium light. Fig.4 also schematically depicts a vehicle, like an automobile, but this may also be a truck, a motor cycle, etc. etc., with automotive lighting 4, e.g. headlights. These automotive lighting 4 may also comprise the lighting device 1200. 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". 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. 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. 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. 2024PF80180 59 In the claims, any reference placed between parentheses shall not be construed as limiting the claim. 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. 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. The various aspects discussed in this patent can be combined in order to provide additional advantages. Further, the person skilled in the art will understand that embodiments can be combined, and that also more than two embodiments can be combined. Furthermore, some of the features can form the basis for one or more divisional applications.

Claims

1. 2024PF80180 60 CLAIMS:

1. A light generating system (1000) comprising a first light source (10), a first quarter wave plate (721), a first polarization based beam director (1510), a reflective polarization maintaining diffuser (710), a first additional light source arrangement (1120), and a light exit (1090), wherein: - the first light source (10) is configured to generate first light source light (11), having a first wavelength λ1; wherein the first light source (10) is selected from the group comprising laser diodes, superluminescent diodes, and stacked multi-junction light-emitting diodes; - the first quarter wave plate (721) is configured in an optical path between the first light source (10) and the reflective polarization maintaining diffuser (710); the first quarter wave plate (721) is a quarter wave plate for λ1; wherein the first quarter wave plate (721) together with the reflective polarization maintaining diffuser (710) are configured to (a) convert light comprising s-polarization into light comprising p-polarization, or (b) convert light comprising p-polarization into light comprising s-polarization; - the first polarization based beam director (1510) is configured in an optical path between the first light source (10) and the reflective polarization maintaining diffuser (710); the first polarization based beam director (1510) is configured upstream of the first quarter wave plate (721); the light generating system (1000) is configured such that the first light source light (11) received by the first polarization based beam director (1510) comprises linear polarized light; wherein the first polarization based beam director (1510) is configured to direct first light source light (11) having a first linear polarization, received by the first polarization based beam director (1510), in an optical path to the reflective polarization maintaining diffuser (710); - the reflective polarization maintaining diffuser (710) is configured to diffuse at least part of the first light source light (11) received by the reflective polarization maintaining diffuser (710) into diffused first light source light (11d); - the first polarization based beam director (1510) is configured to direct diffused first light source light (11d) having a second linear polarization, received by the first polarization based beam director (1510), in an optical path to the light exit (1090); wherein 2024PF80180 61 the first linear polarization and the second polarization are selected from s-polarization and p-polarization; - the first additional light source arrangement (1120) comprises a second light source (20), a first dichroic based beam director (1620), a second quarter wave plate (722), and a second polarization based beam director (1520); - the second light source (20) is configured to generate second light source light (21), having a second wavelength λ2; wherein |λ2-λ1|≥30 nm; wherein the second light source (20) is selected from the group comprising laser diodes, superluminescent diodes, and stacked multi-junction light-emitting diodes; - the first dichroic based beam director (1620) is configured upstream of the first polarization based beam director (1510); the first dichroic based beam director (1620) is configured to direct first light source light (11) and second light source light (21), received by the first dichroic based beam director (1620) in an optical path to the polarization maintaining diffuser (710); - the second quarter wave plate (722) is configured downstream of the first dichroic based beam director (1620) and downstream of the second polarization based beam director (1520) and upstream of the first polarization based beam director (1510); the second quarter wave plate (722) is configured in an optical path between the second light source (20) and the reflective polarization maintaining diffuser (710); the second quarter wave plate (722) is a quarter wave plate for |λ2-λ1|; wherein the second quarter wave plate (722), the first quarter wave plate (721), and the reflective polarization maintaining diffuser (710) together are configured to (a) convert light comprising s-polarization into light comprising p- polarization, or (b) convert light comprising p-polarization into light comprising s- polarization; - the second polarization based beam director (1520) is configured in an optical path between the second light source (20) and the reflective polarization maintaining diffuser (710); the second polarization based beam director (1520) is configured downstream of the first dichroic based beam director (1620) and upstream of the second quarter wave plate (722); the light generating system (1000) is configured such that the second light source light (21) received by the second polarization based beam director (1520) comprises linear polarized light; the second polarization based beam director (1520) is configured to direct second light source light (21) and first light source light (11) having a first linear polarization, received by the second polarization based beam director (1520), in an optical path to the reflective polarization maintaining diffuser (710); 2024PF80180 62 - the reflective polarization diffuser (710) is configured to diffuse at least part of the second light source light (21) received by the reflective polarization maintaining diffuser (710) into diffused second light source light (21d); - the second polarization based beam director (1520) is configured to direct diffused second light source light (21d) having a second linear polarization, received by the second polarization based beam director (1520), in an optical path to the light exit (1090); - the light generating system (1000) is configured to generate in an operational mode of the light generating system (1000) system light (1001) comprising diffused first light source light (11d) and diffused second light source light (21d).

2. The light generating system (1000) according to claim 1, wherein: - the first light source (10) is configured to generate first light source light (11) having a first peak wavelength λp,1selected from the wavelength range of 430-490 nm, wherein the first wavelength λ1 is selected from the wavelength range of λp,1 ± 10 nm; and - the second light source (20) is configured to generate second light source light (21) having a second peak wavelength λp,2 selected from the wavelength range of 430-680 nm, wherein |λp,2-λp,1|≥30 nm; and wherein the second wavelength λ2is selected from the wavelength range of λp,2 ± 10 nm.

3. The light generating system (1000) according to any one of the preceding claims, wherein: - the first light source (10) comprises a laser diode, and wherein the second light source (20) comprises a laser diode; - the light generating system (1000) comprises a first dichroic-based combiner (1710), configured to (a) combine the diffused first light source light (11d) and diffused second light source light (21d), and (b) direct the combined diffused first light source light (11d) and diffused second light source light (21d) in an optical path to the light exit (1090).

4. The light generating system (1000) according to any one of the preceding claims, further comprising a second additional light source arrangement (1130), wherein: - the second additional light source arrangement (1130) comprises a third light source (30), a second dichroic based beam director (1630), a third quarter wave plate (723), and a third polarization based beam director (1530); 2024PF80180 63 - the third light source (30) is to generate third light source light (31), having a third wavelength λ3; wherein |λ3-λ2|≥30 nm and wherein |λ3-λ1|≥30 nm; wherein the third light source (30) is selected from the group comprising laser diodes, superluminescent diodes, and stacked multi-junction light-emitting diodes; - the second dichroic based beam director (1630) is configured upstream of the second polarization based beam director (1520); the second dichroic based beam director (1630) is configured to direct first light source light (11) and third light source light (31), received by the second dichroic based beam director (1630), in an optical path to the polarization maintaining diffuser (710); - the third quarter wave plate (723) is configured downstream of the second dichroic based beam director (1630) and downstream of the third polarization based beam director (1530) and upstream of the second polarization based beam director (1520); the third quarter wave plate (723) is configured in an optical path between the third light source (30) and the reflective polarization maintaining diffuser (710); the third quarter wave plate (723) is a quarter wave plate for |λ3-λ2|; wherein the third quarter wave plate (723), the second quarter wave plate (722), the first quarter wave plate (721), and the reflective polarization maintaining diffuser (710) together are configured to (a) convert light comprising s- polarization into light comprising p-polarization, or (b) convert light comprising p- polarization into light comprising s-polarization; - the third polarization based beam director (1530) is configured in an optical path between the third light source (30) and the reflective polarization maintaining diffuser (710); the third polarization based beam director (1530) is configured downstream of the second dichroic based beam director (1630) and upstream of the third quarter wave plate (723); the light generating system (1000) is configured such that the third light source light (31) received by the third polarization based beam director (1530) comprises linear polarized light; the third polarization based beam director (1530) is configured to direct third light source light (31) having a first linear polarization, received by the third polarization based beam director (1530), in an optical path to the reflective polarization maintaining diffuser (710); - the reflective polarization maintaining diffuser (710) is configured to diffuse at least part of the third light source light (31) received by the reflective polarization maintaining diffuser (710) into diffused third light source light (31d); 2024PF80180 64 - the third polarization based director (1530) is configured to direct diffused third light source light (31d) having a second linear polarization, received by the third polarization based beam director (1530), in an optical path to the light exit (1090); - the light generating system (1000) is configured to generate in an operational mode of the light generating system (1000) system light (1001) comprising diffused first light source light (11d), diffused second light source light (21d), and diffused third light source light (31d).

5. The light generating system (1000) according to claim 4, wherein: - the first light source (10) is configured to generate first light source light (11) having a first peak wavelength λp,1selected from the wavelength range of 430-490 nm, wherein the first wavelength λ1 is selected from the wavelength range of λp,1 ± 10 nm; - the second light source (20) is configured to generate second light source light (21) having a second peak wavelength λp,2 selected from the wavelength range of 430-680 nm, wherein |λp,2-λp,1|≥30 nm; and wherein the second wavelength λ2is selected from the wavelength range of λp,2 ± 10 nm; and - the third light source (30) is configured to generate third light source light (31) having a third peak wavelength λp,3 selected from the wavelength range of 430-680 nm, wherein |λp,3-λp,2|≥30 nm; and wherein the third wavelength λ3is selected from the wavelength range of λp,3 ± 10 nm.

6. The light generating system (1000) according to claim 5, wherein the second peak wavelength λp,2 is selected from the wavelength range of 490-590 nm, and wherein the third peak wavelength λp,3is selected from the wavelength range of 590-680 nm.

7. The light generating system (1000) according to any one of the preceding claims 4-6, wherein: - the first light source (10) comprises a laser diode, wherein the second light source (20) comprises a laser diode, and wherein the third light source (30) comprises a laser diode; - the light generating system (1000) comprises further dichroic-based combiners (1710,1720...), configured to (a) combine the diffused first light source light (11d), diffused second light source light (21d), and diffused third light source light (31d), and (b) direct the 2024PF80180 65 combined diffused first light source light diffused second light source light (21d), and diffused third light source light (31d) in an optical path to the light exit (1090).

8. The light generating system (1000) according to any one of the preceding claims 4 - 7, further comprising a third additional light source arrangement (1140), wherein: - the third additional light source arrangement (1140) comprises a fourth light source (40), a third dichroic based beam director (1640), a fourth quarter wave plate (724), and a fourth polarization based beam director (1540); - the fourth light source (40) is configured to generate fourth light source light (41), having a fourth wavelength λ4; wherein |λ4-λ3|≥30 nm, and |λ4-λ2|≥30 nm, and |λ4-λ1|≥30 nm; wherein the fourth light source (40) is selected from the group comprising laser diodes, superluminescent diodes, and stacked multi-junction light-emitting diodes; - the third dichroic based beam director (1640) is configured upstream of the third polarization based beam director (1530); the third dichroic based beam director (1640) is configured to direct first light source light (11) and fourth light source light (41), received by the third dichroic based beam director (1640) in an optical path to the polarization maintaining diffuser (710); - the fourth quarter wave plate (724) is configured downstream of the third dichroic based beam director (1640) and downstream of the fourth polarization based beam director (1540) and upstream of the third polarization based beam director (1530); the fourth quarter wave plate (724) is configured in an optical path between the fourth light source (40) and the reflective polarization maintaining diffuser (710); the fourth quarter wave plate (724) is a quarter wave plate for |λ4-λ3|; wherein the fourth quarter wave plate (724), the third quarter wave plate (723), the second quarter wave plate (722), the first quarter wave plate (721), and the reflective polarization maintaining diffuser (710) together are configured to (a) convert light comprising s-polarization into light comprising p-polarization, or (b) convert light comprising p-polarization into light comprising s-polarization; - the fourth polarization based beam director (1540) is configured in an optical path between the fourth light source (40) and the reflective polarization maintaining diffuser (710); the fourth polarization based beam director (1540) is configured downstream of the third dichroic based beam director (1640) and upstream of the fourth quarter wave plate (724); the light generating system (1000) is configured such that the fourth light source light (41) received by the fourth polarization based beam director (1540) comprises linear polarized light; the fourth polarization based beam director (1540) is configured to direct 2024PF80180 66 fourth light source light (41) having a first polarization, received by the fourth polarization based beam director (1540), in an optical path to the reflective polarization maintaining diffuser (710); - the reflective polarization maintaining diffuser (710) is configured to diffuse at least part of the fourth light source light (41) received by the reflective polarization maintaining diffuser (710) into diffused fourth light source light (41d); - the fourth polarization based beam director (1540) is configured to direct diffused fourth light source light (41d) having a second linear polarization, received by the fourth polarization based beam director (1540), in an optical path to the light exit (1090); - the light generating system (1000) is configured to generate in an operational mode of the light generating system (1000) system light (1001) comprising diffused first light source light (11d), diffused second light source light (21d), diffused third light source light (31d), and diffused fourth light source light (41d).

9. The light generating system (1000) according to claims 5 and 8, wherein: - the fourth light source (40) is configured to generate fourth light source light (41) having a fourth peak wavelength λp,4selected from the wavelength range of 430-680 nm, wherein |λp,4-λp,3|≥30 nm; and wherein the fourth wavelength λ4 is selected from the wavelength range of λp,4± 10 nm.

10. The light generating system (1000) according to any one of claims 8-9, wherein the second peak wavelength λp,2is selected from the wavelength range of 500-540 nm, the third peak wavelength λp,3 is selected from the wavelength range of 540-600 nm, and wherein the fourth peak wavelength λp,4is selected from the wavelength range of 600-670 nm.

11. The light generating system (1000) according to any one of the preceding claims 8-10, wherein: - the fourth light source (40) comprises a laser diode; - the light generating system (1000) comprises further dichroic-based combiners (1710,1720...), configured to (a) combine the diffused first light source light (11d), diffused second light source light (21d), diffused third light source light (31d), and diffused fourth light source light (41d), and (b) direct the combined diffused first light source light (11d), 2024PF80180 67 diffused second light source light (21d), third light source light (31d), and diffused fourth light source light (41d) in an optical path to the light exit (1090).

12. The light generating system (1000) according to any one of the preceding claims, further comprising a luminescent material (200) and optics (500); wherein the light generating system (1000) comprises a source of excitation light (1); wherein the luminescent material (200) is configured to convert at least part of the excitation light (1) into luminescent material light (201); wherein the optics (500) are configured to direct the luminescent material light (201) in an optical path to the light exit (1090); wherein the light generating system (1000) is configured to generate in an operational mode of the light generating system (1000) system light (1001) further comprising the luminescent material light (201).

13. The light generating system (1000) according to claim 12, wherein the luminescent material (200) comprises a luminescent material of the type A3B5O12: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.

14. The light generating system (1000) according to any one of the preceding claims, further comprising a control system (300), wherein: - the control system (300) is configured to control a spectral power distribution of the system light (1001) by individually controlling the light sources (10,20,.....); and - in an operational mode of the light generating system (1000), the system light (1001) has a color rendering index of at least 65 and a correlated color temperature selected from the range of 2000-12000 K.

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

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