Laser-phosphor based stage lighting device providing ctt control

Abstract

The invention provides a light generating system (1000). The light generating system (1000) comprises a first light generating device (2100), a light emitting body (210), a reflective polarizer (500) and a control system (300), wherein the first light generating device (2100) is configured to generate pump light (2101) having a controllable polarization, wherein the polarization is controllable between a first polarization and a second polarization; wherein the first light generating device (2100) comprises a first solid state light source (10) selected from the group comprising a super light emitting diode and a laser diode; wherein the luminophor (210) comprises a luminescent material (200); wherein the luminophor (210) is configured to (a) transmit at least a portion of the pump light (2101) (comprising the first polarization and / or the second polarization) and (b) convert at least a portion of the pump light (2101) (comprising the first polarization and / or the second polarization) into luminescent material light (201); wherein the reflective polarizer (500) is arranged downstream of the light emitter (210); wherein the reflective polarizer (500) is transmissive for at least a portion of the luminescent material light (201); wherein the reflective polarizer (500) has a higher transmittance for the pump light (2101) comprising the first polarization than for the pump light (2101) comprising the second polarization, and wherein the reflective polarizer (500) has a lower reflectivity for the pump light (2101) comprising the first polarization than for the pump light (2101) comprising the second polarization; wherein the light generating system (1000) is configured to generate system light (1001); and wherein the control system (300) is configured to control spectral characteristics of the system light (1001) by controlling polarization of the pump light (2101).

Description

Technical Field

[0001] The present invention relates to a light generation system. The present invention also relates to an illumination device including such a system. Background Art

[0002] US2021156526A1 describes a light source device including a laser light source for emitting first light, and a refractive optical element disposed on an outgoing light path of the laser light source and configured to guide the first light to a light conversion device. The refractive optical element includes an outgoing light surface, and the light refracted by the outgoing light surface of the refractive optical element is deflected toward the light conversion device for emission. The light conversion device is disposed on the outgoing light side of the refractive optical element, and an incident surface thereof is the same surface as the outgoing light surface. The medium of the incident surface of the light conversion device has a Brewster angle α, and the outgoing light of the refractive optical element is obliquely incident on the light conversion device at an incident angle of α - 20° to α + 10°. In addition, a light collecting device is disposed on the outgoing light side of the light conversion device and configured to collect and emit the light emitted from the light conversion device.

[0003] CN107272312A discloses an illumination device including a first light source for emitting first light and a second light source for emitting second light. A beam splitting device receives combined light including the first light and the second light, and guides the first light and the second light along a first light path and a second light path for emission according to different transmission and reflection characteristics. A wavelength conversion device receives the light emitted from the first light path and converts the light into first converted light. A scattering device scatters the light from the second light path into diffused light. The diffused light and the converted light are combined and emitted by the illumination device.

[0004] WO2022 / 034002A1 discloses a light generation system including a light generation device for generating polarized laser radiation, a luminescent material layer, and optical devices. The luminescent material layer converts at least a part of the polarized laser. The optical devices include a first optical device and a second optical device, wherein the first optical device is configured to change the polarization of the polarized laser radiation, and wherein the second optical device performs one or more of the following on the polarized laser radiation: (i) polarization-dependent transmission and (ii) polarization-dependent reflection. The light generation device and the optical devices are configured such that, with respect to the light path of the luminescent material radiation emitted from the luminescent material, the second optical device is disposed downstream of the first optical device and the luminescent material. Summary of the Invention

[0005] Applications such as stage lighting, stadium lighting, traffic infrastructure, etc. may require the use of high-intensity white light. In addition, it is also desirable to control the spectral power distribution of the light provided by the light generation system and / or control the correlated color temperature of the light provided. However, current devices may not be able to control the spectral power distribution (and CCT) efficiently and relatively simply, and / or may not be able to provide high-power lighting.

[0006] Accordingly, an aspect of the present invention is to provide a light generation system which preferably also at least partially eliminates one or more of the above disadvantages. The object of the present invention is to overcome or improve at least one of the disadvantages of the prior art, or to provide a useful alternative.

[0007] According to a first aspect, the present invention provides a light generation system, which system includes a first light generation device, a light emitter, a reflective polarizer, and a control system. In an embodiment, the first light generation device may be configured to generate pump light having controllable polarization. In particular, the polarization is controllable between a first polarization and a second polarization. Additionally, in an embodiment, the first light generation device may include a first solid-state light source selected from the group including a superluminescent diode and a laser diode. The light emitter is disposed downstream of the first light generation device, and during operation of the light generation system, the pump light generated by the first light generation device is incident on the light emitter. In an embodiment, the light emitter may include a luminescent material. In particular, the light emitter may be configured to: (a) transmit at least a portion of the pump light (including the first polarization and / or the second polarization); and (b) convert at least a portion of the pump light (including the first polarization and / or the second polarization) into luminescent material light. In an embodiment, the reflective polarizer may be disposed downstream of the light emitter. In particular, the reflective polarizer is transmissive to at least a portion of the luminescent material light. More particularly, the reflective polarizer may have a higher transmittance for pump light including the first polarization than for pump light including the second polarization. Additionally, in an embodiment, the reflective polarizer may have a lower reflectance for pump light including the first polarization than for pump light including the second polarization. In an embodiment, the light generation system may be configured to generate system light. In particular, the system light may include white light having a correlated color temperature in the range of 1800K to 10000K and a color rendering index of at least 70. Additionally, in an embodiment, the control system may be configured to control the spectral characteristics of the system light by controlling the polarization of the pump light.Accordingly, in certain embodiments, the present invention provides a light generation system that includes a first light generation device, a luminescent body, a reflective polarizer, and a control system; wherein the first light generation device is configured to generate pump light having a controllable polarization, wherein the polarization is controllable between a first polarization and a second polarization; wherein the first light generation device includes a first solid-state light source selected from the group consisting of a superluminescent diode and a laser diode; wherein the luminescent body includes a luminescent material; wherein the luminescent body is configured to (a) transmit at least a portion of the pump light (including the first polarization and / or the second polarization) and (b) convert at least a portion of the pump light (including the first polarization and / or the second polarization) into luminescent material light; wherein the reflective polarizer is disposed downstream of the luminescent body; wherein the reflective polarizer is transmissive to at least a portion of the luminescent material light; wherein the reflective polarizer has a higher transmittance for pump light including the first polarization than for pump light including the second polarization, and wherein the reflective polarizer has a lower reflectance for pump light including the first polarization than for pump light including the second polarization; wherein the light generation system is configured to generate system light; wherein in an embodiment, the system light can be white light having a correlated color temperature in the range of 1800K to 10000K and a color rendering index of at least 70; and wherein the control system is configured to control the spectral characteristics of the system light by controlling the polarization of the pump light. In a first operating mode of the light generation system, the system light includes a first radiant flux ratio X of the pump light and the luminescent material light. 1 / Y 1 ; wherein, in a second operating mode of the light generation system, the system light includes a second radiant flux ratio X of the pump light and the luminescent material light 2 / Y 2 , and wherein X 1 / Y 1 >X 2 / Y 2 . The luminescent body is at least partially transparent to the pump light.

[0008] The present invention can provide high-intensity white light. Further, the spectral distribution of the light provided by the light generation system can be controlled (only) by controlling the polarization of the pump light. Accordingly, in an embodiment, the correlated color temperature (CCT) of the system light can be controlled by controlling the polarization of the pump light. Further, the spectral power distribution of the system light can be controlled. In this manner, the present invention can provide, in an embodiment, a laser-phosphor-based stage lighting device that provides CCT control, and / or for lighting of stages, stadiums, or transportation infrastructure lighting.

[0009] As previously described, the present invention provides a light generation system that, in an embodiment, includes a first light generation device, a luminescent body, a reflective polarizer, and a control system. Embodiments of these elements will be described in more detail below.

[0010] The first light generating device may be configured to generate pump light having a controllable polarization. The term "polarization" may refer to the electromagnetic oscillations in the transverse wave of light that includes light along a specific direction. Thus, in an embodiment, the pump light may be polarized in a desired polarization direction. Further, the polarization is controllable particularly between a first polarization and a second polarization. In an embodiment, the first polarization is a p-polarization and the second polarization is an s-polarization. However, in other embodiments, the situation may be reversed. In an embodiment, the polarization may be obtained by using a light source that generates polarized light, or in an embodiment, by using a combination of a light source and polarization optics that applies the desired polarization to the light generated by the light source. Some options will be described below.

[0011] In an embodiment, the first light generating device may include a light source, particularly a solid-state light source. The term "light source" may in principle refer to any light source known in the art. It may be a conventional (tungsten filament) bulb, a low-pressure mercury lamp, a high-pressure mercury lamp, a fluorescent lamp, an LED (light emitting diode). In a particular embodiment, the light source includes a solid-state LED light source (such as an LED or a laser diode (or "diode laser")). The term "light source" may also refer to a plurality of light sources, such as 2 - 2000 (solid-state) LED light sources. Thus, the term "LED" may also refer to a plurality of LEDs. Further, in an embodiment, the term "light source" may also refer to a so-called chip-on-board (COB) light source. The term "COB" particularly refers to an LED chip in the form of a semiconductor chip that is neither encapsulated nor connected, but is directly mounted onto a substrate (such as a PCB). Thus, a plurality of light-emitting semiconductor light sources may be configured on the same substrate. In an embodiment, a COB is a plurality of LED chips that are configured together as a single lighting module.

[0012] The term "light source" may also refer to a chip-scale package (CSP). The CSP may include a single solid-state die on which a layer including a light-emitting material is disposed. The term "light source" may also refer to a mid-power package. The mid-power package may include one or more solid-state dies. These dies may be covered by a layer including a light-emitting material. The die size may be equal to or less than 2 mm, such as in the range of 0.2 mm - 2 mm. Thus, in an embodiment, the light source includes a solid-state light source. Additionally, in a particular embodiment, the light source includes an LED in a chip-scale package. Herein, the term "light source" may also particularly refer to a small solid-state light source, such as a light source having a mini size or a micro size. For example, the light source may include one or more mini LEDs and micro LEDs. In particular, in an embodiment, the light source includes a micro LED or "microLED" or "μLED". Herein, the term mini size or mini LED particularly refers to a solid-state light source selected from the range of 100 μm to 1 mm in size (such as die size, especially length and width). Herein, the term μ size or micro LED particularly refers to a solid-state light source selected from the range of 100 μm and less in size (such as die size, especially length and width).

[0013] The light source may have a light-emitting surface. For a conventional light source, such as a light bulb or a fluorescent lamp, the light-emitting surface may be the outer surface of a glass or quartz housing. For an LED, the light-emitting surface may be, for example, the LED die, or when resin is applied to the LED die, it may be the outer surface of the resin. In principle, the light-emitting surface may also be the end of an optical fiber. The term emitting surface particularly refers to the part of the light source where light actually exits or escapes from the light source. The light source is configured to provide a light beam. This light beam thus exits from the light-emitting surface of the light source.

[0014] Similarly, a light-generating device may include a light-emitting surface, such as an end window. Additionally, a light-generating system may also include a light-emitting surface, such as an end window.

[0015] The term "light source" may refer to a semiconductor light-emitting device, such as a light-emitting diode (LED), a resonant-cavity light-emitting diode (RCLED), a vertical-cavity surface-emitting laser (VCSEL), 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 particular embodiment, the light source includes a solid-state light source (such as an LED or a laser diode). In one embodiment, the light source includes an LED (light-emitting diode). The term "light source" or "solid-state light source" may also refer to a superluminescent diode (SLED).

[0016] The term LED may also refer to multiple LEDs.

[0017] The term "light source" may also refer to multiple (substantially identical (or different)) light sources, such as 2 - 2000 solid-state light sources. In an embodiment, the light source may include one or more micro-optical elements (micro-lens arrays) that are downstream of a single solid-state light source (such as an LED), or downstream of multiple solid-state light sources (e.g., shared by multiple LEDs). In an embodiment, the light source may include an LED with on-chip optics. In an embodiment, the light source includes a pixelated single LED (with or without optics) (providing on-chip beam steering in an embodiment).

[0018] In an embodiment, the light source may be configured to provide primary radiation and be used directly, such as for example a blue light source (such as 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 may not include a luminescent material ("phosphor"), and thus may be referred to as direct color LEDs.

[0019] However, in other embodiments, the light source may be configured to provide primary radiation, and a portion of the primary radiation is converted into secondary radiation. The secondary radiation may be based on the conversion of a luminescent material. Thus, the secondary radiation may also be expressed as luminescent material radiation. In some embodiments, the luminescent material may be included in the light source, such as an LED having a luminescent material layer or a dome including a luminescent material. Such LEDs may be referred to as phosphor-converted LEDs or PC LEDs (phosphor-converted LEDs). In other embodiments, the luminescent material may be configured at a certain distance ("remote") from the light source, such as an LED where the luminescent material layer does not physically contact the LED die. Thus, in a particular embodiment, the light source may be a light source that emits at least light selected in the range of wavelengths from 380 nm - 470 nm during operation. However, other wavelengths are also possible. This light may be partially converted by the luminescent material.

[0020] In an embodiment, the light generation device may include a luminescent material. In an embodiment, the light generation device may include a PCLED. In other embodiments, the light generation device may include a direct LED (i.e., without a phosphor). In an embodiment, the light generation device may include a laser device, such as a laser diode. In an embodiment, the light generation device may include a superluminescent diode. Thus, in a particular embodiment, the light source may be selected from the group of laser diodes and superluminescent diodes. In other embodiments, the light source may include an LED.

[0021] The light source may in particular be configured to generate source light having an optical axis (O) (beam shape) and a spectral power distribution. In some embodiments, the source light may include one or more bands, the bandwidth of which is known for lasers.

[0022] Thus, the term "light source" can refer to the light generating element itself, such as a solid-state light source, or, for example, to a package of a light generating element (such as a solid-state light source) and one or more elements including a luminescent material and (other) optical devices (such as lenses, collimators). A light converter element ("converter element" or "converter") can include an element containing a luminescent material. For example, a solid-state light source itself (such as a blue LED) is a light source. A combination of a solid-state light source (as a 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) can also be a light source (but can also be represented as a light generating device). Thus, a white LED is a light source (but can also be represented as a (white) light generating device).

[0023] The term "light source" in this document can also refer to a light source including a solid-state light source, such as an LED or a laser diode or a superluminescent diode.

[0024] The term "light source" can also refer, in embodiments, to a light source based on light conversion, such as a light source combined with a luminescent converter material. Thus, the term "light source" can also refer to a combination of an LED and a luminescent material configured to convert at least a portion of the LED radiation, or a (diode) laser and a luminescent material configured to convert at least a portion of the (diode) laser radiation.

[0025] In embodiments, the term "light source" can also refer to a combination of a light source (such as an LED) and an optical filter that can change the spectral power distribution of the light generated by the light source. In particular, the term "light generating device" can be used to refer to a light source and other (optical components), such as, for example, an optical filter and / or a beam shaping element, etc.

[0026] In embodiments, the phrase "different light sources" or "multiple different light sources" and similar phrases can refer to multiple solid-state light sources selected from at least two different bins. Similarly, in embodiments, the phrase "same light source" or "multiple same light sources" and similar phrases can refer to multiple solid-state light sources selected from the same bin.

[0027] The term "solid-state light source" or "solid-state material light source" and similar terms may particularly refer to semiconductor light sources, such as light emitting diodes (LEDs), laser diodes or superluminescent diodes.

[0028] The term "laser light source" specifically refers to a laser. Such a laser can in particular be configured to generate laser light source light having one or more wavelengths in the UV, visible or infrared, in particular light having a wavelength selected from the spectral wavelength range of 200 nm - 2000 nm (such as 300 nm - 1500 nm). The term "laser" specifically refers to a device that emits light through a process of stimulated emission of electromagnetic radiation.

[0029] In particular, in embodiments, the term "laser" may refer to a solid-state laser. In certain embodiments, the term "laser" or "laser light source" or similar terms refer to a laser diode (or diode laser).

[0030] Accordingly, in embodiments, the light source includes a laser light source. In embodiments, the term "laser" or "solid-state laser" or "solid-state material laser" may refer to one or more of the following: cerium-doped lithium strontium (or calcium) aluminum fluoride (Ce:LiSAF, Ce:LiCAF), chromium-doped alexandrite laser, chromium zinc selenide (Cr:ZnSe) laser, samarium-doped calcium fluoride (Sm:CaF 2 ) laser, Er:YAG laser, erbium and erbium-ytterbium co-doped glass laser, F-center laser, holmium YAG (Ho:YAG) laser, Nd:YAG laser, NdCrYAG laser, neodymium-doped yttrium calcium oxyborate Nd:YCa 4 O(BO 3 ) 3 or Nd:YCOB, neodymium-doped yttrium orthovanadate (Nd:YVO 4 ) laser, neodymium glass (Nd:glass) laser, neodymium YLF (Nd:YLF) solid-state laser, promethium-147-doped phosphate glass (147Pm 3+ :glass) solid-state laser, ruby laser (Al 2 O 3 :Cr 3+ ), thulium YAG (Tm:YAG) laser, titanium sapphire (Ti:sapphire; Al 2 O 3 :Ti 3+ ) laser, uranium-doped calcium fluoride (U:CaF 2 ) solid-state laser, ytterbium-doped glass laser (rod, plate / sheet, fiber), ytterbium YAG (Yb:YAG) laser, Yb 2 O 3 (glass or ceramic) laser, etc.

[0031] For example, including second and third harmonic generation embodiments, the light source may include one or more of the following: F-center laser, neodymium orthovanadate (Nd:YVO 4 ) laser, promethium-147-doped phosphate glass (147Pm 3+ :glass), and titanium sapphire (Ti:sapphire; Al 2 O 3 :Ti 3+ ) laser. For example, considering second and third harmonic generation, such light sources can be used to generate blue light.

[0032] In an embodiment, the term "laser" or "solid-state laser" or "solid-state material laser" may refer to a semiconductor laser diode, such as one or more of GaN, InGaN, AlGaInP, AlGaAs, InGaAsP, lead salts, vertical-cavity surface-emitting lasers (VCSELs), quantum cascade lasers, hybrid silicon lasers, etc.

[0033] The laser may be combined with an upconverter to achieve a shorter (laser) wavelength. For example, upconversion can be obtained using certain (trivalent) rare earth ions, or upconversion can be obtained using a non-linear crystal. Alternatively, the laser may be combined with a downconverter (such as a dye laser) to achieve a longer (laser) wavelength.

[0034] As can be seen from the following, the term "laser light source" may also refer to a plurality of (different or identical) laser light sources. In a particular embodiment, the term "laser light source" may refer to a plurality of (N) (identical) laser light sources. In an embodiment, N = 2 or greater. In a particular embodiment, N may be at least 5, such as in particular at least 8. In this way, higher brightness can be obtained. In an embodiment, the laser light sources may be arranged in a laser group (see also above). In an embodiment, the laser group may include a heat sink and / or optics (e.g., a lens for collimating the laser). Thus, in an embodiment, the lasers in the laser group (or "laser array group") may share the same optics.

[0035] The laser light source is configured to generate laser light source light (or "laser"). The source light may consist essentially of laser light source light. The source light may also include the laser light source light of two or more (different or identical) laser light sources. For example, the laser light source light of two or more (different or identical) laser light sources may be coupled into an optical waveguide to provide a single beam including the laser light source light of two or more (different or identical) laser light sources. In a particular embodiment, the source light is thus particularly collimated source light. In a further embodiment, the source light is in particular (collimated) laser light source light.

[0036] In an embodiment, the laser light source light may include one or more bands, the bandwidth of which is known for the laser. In a particular embodiment, the (plural) bands may be relatively sharp lines, such as having a full width at half maximum (FWHM) in the range of less than 20 nm at room temperature (RT), such as equal to or less than 10 nm. Thus, the source light has a spectral power distribution (intensity on an energy scale as a function of wavelength), which may include one or more (narrow) bands.

[0037] The light beam (of the light source light) can be a focused or collimated (laser) light source beam. The term "focused" particularly refers to being converged into a small spot. This small spot can be located in the discrete converter region, or (slightly) upstream or (slightly) downstream thereof. In particular, the focusing and / or collimation can be such that the cross-sectional shape (perpendicular to the optical axis) of the light beam at the (side) of the discrete converter region is substantially no larger than the cross-sectional shape (perpendicular to the optical axis) of the discrete converter region (at the position where the light source light irradiates the discrete converter region). The focusing can be carried out by one or more optical devices (such as (focusing) lenses). In particular, two lenses can be applied to focus the laser light source light. The collimation can be carried out by one or more (other) optical devices (such as collimating elements, such as lenses and / or parabolic mirrors). In an embodiment, the (laser) light source beam can be relatively highly collimated, such as ≤2° (FWHM) in an embodiment, more particularly ≤1° (FWHM), and most particularly ≤0.5° (FWHM). Thus, ≤2° (FWHM) can be regarded as (highly) collimated light source light. Optical devices can be used to provide (high) collimation (see also above).

[0038] The terms "solid-state material laser" and similar terms can refer to solid-state lasers based on crystals or glass bodies doped with ions (such as transition metal ions and / or lanthanide ions), fiber lasers, photonic crystal lasers, semiconductor lasers (such as vertical-cavity surface-emitting lasers (VCSELs)), etc.

[0039] The term "solid-state light source" and its similar terms can particularly refer to semiconductor light sources, such as light-emitting diodes (LEDs), laser diodes, or superluminescent diodes. Instead of the term "solid-state light source", the term "semiconductor-based light source" can also be applied. Thus, the term "semiconductor-based light source" can refer to, for example, one or more of light-emitting diodes (LEDs), laser diodes, and superluminescent diodes. Thus, the light generation device can include one or more of light-emitting diodes (LEDs), laser diodes, and superluminescent diodes.

[0040] Superluminescent diodes are known in the art. A superluminescent diode can refer to a semiconductor device that can emit low-coherence light with a broad spectrum like an LED, while having a brightness comparable to that of a laser diode.

[0041] For example, US2020192017 states: "Using prior art, a single SLED can emit a bandwidth of up to 50nm - 70nm in the wavelength range of 800nm - 900nm, with sufficient spectral flatness and sufficient output power. In the visible light range for display applications, i.e., in the wavelength range of 450nm - 650nm, using prior art, a single SLED can emit a bandwidth of up to 10nm - 30nm. For display or projector applications that require red (640nm), green (520nm), and blue (450nm) (i.e., RGB) emissions, these emission bandwidths are too small." Additionally, in the book "Edge Emitting Laser Diodes and Superluminescent Diodes", Szymon Stanczyk, Anna Kafar, Dario Schiavon, Stephen Najda, Thomas Slight, and Piotr Perlin describe superluminescent diodes, book editors: Fabrizio Roccaforte, Mike Leszczynski, first published date: August 3, 2020 https: / / doi.org / 10.1002 / 9783527825264.ch9inchapter9.3, superluminescent diode. This book, especially Chapter 9.3, is incorporated herein by reference. It is pointed out therein that a superluminescent diode (SLD) is a transmitter that combines the characteristics of a laser diode and a light-emitting diode. SLD emitters utilize stimulated emission, which means that these devices operate at a current density similar to that of a laser diode. The main difference between an LD and an SLD is that in an SLD, the device waveguide can be designed in a special way to prevent the formation of standing waves and lasing. Nevertheless, the presence of the waveguide still ensures the emission of a high-quality light beam, where the light has high spatial coherence, but at the same time the light is characterized by low temporal coherence, and "currently, the most successful designs of nitride SLDs are curved, arc-shaped or tilted waveguide geometries and tilted facet geometries, and in all cases, the front end of the waveguide intersects the device facet in a tilted manner, as shown in Figure 9.10. The tilted waveguide suppresses the reflection of light from the facet to the waveguide by guiding the light outside the un-pumped region of the device chip where there is loss". Therefore, an SLD can in particular be a semiconductor light source in which the spontaneously emitted light is amplified by stimulated emission in the active region of the device. This emission is called "superluminescence". The superluminescent diode combines the high power and brightness of a laser diode with the low coherence of a conventional light-emitting diode. The low (temporal) coherence of the light source has the advantage that speckle is significantly reduced or invisible, and compared with a laser diode, the emission spectral distribution is wider and can be better suited for lighting applications. In particular, as the current changes, the spectral power distribution of the superluminescent diode may change. In this way, the spectral power distribution can be controlled. For example, see Optics Express Vol.26, Issue 20, pp.26355-26364 by Abdullah A. Alatawi et al., https: / / doi.org / 10.1364 / OE.26.026355 .

[0042] In particular, in an embodiment, the first light generating device may include a first solid-state light source selected from the group consisting of a superluminescent diode and a laser diode. It should be noted that in an embodiment, the laser can provide light that is almost completely polarized in a specific direction. However, in an alternative embodiment, polarization optical elements (such as polarization filters) can be (additionally) used to polarize the light to a desired polarization direction. In addition, the polarization optical element can be used to change the polarization. These features will be discussed further below.

[0043] In addition, the light generating system may include a light emitter. The light emitter is particularly configured downstream of the first light generating device. The terms "upstream" and "downstream" refer to the arrangement of an article or feature relative to the propagation of light from the light generating device (here particularly referring to the light source), where, relative to a first position within the light beam from the light generating device, a second position closer to the light generating device within the light beam is "upstream", and a third position farther from the light generating device within the light beam is "downstream".

[0044] In particular, the light emitter may include a luminescent material. In particular, the light emitter may be configured to: (a) transmit at least a portion of the pump light (including the first polarization and / or the second polarization); and (b) convert at least a portion of the pump light (including the first polarization and / or the second polarization) into luminescent material light. In some embodiments, the light emitter may partially transmit light of certain wavelengths. Thus, a portion of the pump light incident on the light emitter may be transmitted without undergoing any conversion. Additionally, in some embodiments, a portion of the pump light may also be converted into luminescent material light when incident on the light emitter. By selecting the thickness of the light emitter and the amount of the luminescent material, the light emitter may be configured such that a portion of the pump light is converted and a portion of the pump light is transmitted (which is known to those skilled in the art and may follow the Lambert-Beer law). Thus, in this way, the light additionally provided downstream of the light emitter may include a combination of both the pump light and the luminescent material light. These characteristics will be discussed in detail below.

[0045] Furthermore, the light generation system may also include a reflective polarizer. In an embodiment, the reflective polarizer may be particularly configured downstream of the light emitter. In particular, the reflective polarizer may be transmissive for at least a portion of the luminescent material light. In this way, the luminescent material light generated in the light emitter and propagated to the reflective polarizer may be at least partially transmitted. In an embodiment, the reflective polarizer may have a higher transmittance for the pump light including the first polarization than for the pump light including the second polarization. Additionally, in an embodiment, the reflective polarizer may have a lower reflectance for the pump light including the first polarization than for the pump light including the second polarization.

[0046] In particular, a combination of (a) a higher transmittance and a lower reflectance for the pump light including the first polarization, and (b) a lower transmittance and a higher reflectance for the pump light including the second polarization may provide the benefit of allowing the spectral power distribution of the system light, particularly the CCT, to be controlled by controlling the ratio of the pump light including the first polarization to the pump light including the second polarization.

[0047] As described above, some of the pump light can be transmitted through the luminescent body without being converted into luminescent material light. Thus, in particular, the (unconverted) pump light can be transmitted (through the luminescent body) and incident on the reflective polarizer. As described above, the reflective polarizer can have a higher transmittance and a lower reflectance for pump light including a first polarization. Thus, in particular, a portion of the pump light including the first polarization can be transmitted through the reflective polarizer. Similarly, in an embodiment, the reflective polarizer can have a lower transmittance and a higher reflectance for pump light including a second polarization. Thus, in particular, a portion of the pump light including the second polarization can be reflected back upstream by the reflective polarizer. The reflection of the pump light including the second polarization (at the reflective polarizer) can be beneficial because the reflected pump light can, in particular, propagate again through at least a portion of the luminescent body. Thus, in this way, a portion of the unconverted pump light including the second polarization that is reflected at the reflective polarizer can be converted into luminescent material light when passing through the luminescent body a second time. A portion of the generated luminescent material light that is incident on the reflective polarizer can also be transmitted (since the reflective polarizer can be transmissive for the luminescent material light; see also above).

[0048] In this way, by controlling the polarization of the pump light, the spectral power distribution of the light downstream of the reflective polarizer can be controlled. A relatively high proportion of the first polarization pump light may, for example, result in the (system) light having a relatively high blue light content, such as, in particular, a relatively high CCT. A relatively high proportion of the second polarization pump light may, for example, result in the (system) light having a relatively low blue light content, such as, in particular, a relatively low CCT. Thus, in an embodiment, by controlling the polarization, the (relative) amount of luminescent material light (in the system light) coupled out of the system can be increased or decreased.

[0049] However, in other embodiments, the reflective polarizer can also be configured such that the reflective polarizer can have a higher transmittance for pump light including the second polarization than for pump light including the first polarization. Additionally, in an embodiment, the reflective polarizer can have a lower reflectance for pump light including the second polarization than for pump light including the first polarization. Thus, in such an embodiment, in particular, the intensity and / or spectral composition of the light coupled out of the system can be controlled by controlling the polarization of the generated pump light. However, the former (multiple) embodiments are specifically discussed herein, i.e., (a) the reflective polarizer can have a higher transmittance for pump light including the first polarization than for pump light including the second polarization; and (b) the reflective polarizer can have a lower reflectance for pump light including the first polarization than for pump light including the second polarization. It should be noted that, in an embodiment, the first polarization can be p polarization and the second polarization can be s polarization (and vice versa).

[0050] In particular, the light generation system can be configured to generate system light (i.e., light coupled out of the system). The system light can include luminescent material light and pump light in an operating mode. Thus, in an embodiment, the spectral power distribution of the system light can be controlled by controlling the polarization of the pump light. Accordingly, the light generation system can include a control system or can be functionally coupled to a control system (configured to control the system light). From the foregoing, controlling the system light can include controlling the polarization of the pump light and the radiant flux of the pump light. In particular for the former, the spectral power distribution of the system light can be controlled.

[0051] In an embodiment, the control system can be configured to control (or operate in an operating mode) the light generation system. The term "control" and its like terms at least particularly refer to determining the behavior of an element or supervising the operation of an element. Thus, "control" and its like terms herein can, for example, refer to imposing behavior on an element (determining the behavior of an element or supervising the operation of an element), such as measuring, displaying, actuating, turning on, switching, changing temperature, etc. In addition to this, the term "control" and its like terms can also include monitoring. Thus, "control" and its like terms can include imposing behavior on an element and imposing behavior on an element and monitoring the element. The control of an element can be carried out by a control system (also referred to as a "controller"). Accordingly, the control system and the element can be at least temporarily or permanently functionally coupled. The element can include the control system. In an embodiment, the control system and the element can be not physically coupled. The control can be carried out by wired and / or wireless control. The term "control system" can also refer to a plurality of different control systems, which are particularly functionally coupled. For example, one of the control systems can be a main control system, and one or more other control systems can be slave control systems. The control system can include a user interface or can be functionally coupled to a user interface.

[0052] The control system can also be configured to receive and execute instructions from a remote controller. In some embodiments, the control system can be controlled via an application on a device, such as a portable device like a smart phone, an I-Phone, a tablet computer, etc. Thus, the device does not necessarily need to be coupled to the lighting system but can be (temporarily) functionally coupled to the lighting system.

[0053] Thus, in some embodiments, the control system can also be configured to be controlled by an application on a remote device. In such embodiments, the control system of the lighting system can be a slave control system or operate in a slave mode. For example, the lighting system can be identified by a code, particularly a unique code for the corresponding lighting system. The control system of the lighting system can be configured to be controlled by an external control system that accesses the lighting system based on knowledge of a (unique) code input via a user interface (e.g., a QR code reader) of an optical sensor. The lighting system can also include means for communicating with other systems or devices, such as based on Bluetooth, Thread, WIFI, LiFi, ZigBee, BLE, WiMAX, or other wireless technologies.

[0054] The system, apparatus, or device can perform actions in a "mode" or "operating mode" or "mode of operation" or "operational mode". The term "operational mode" can also be expressed as a "control mode". Similarly, in a method, actions, phases, or steps can be performed in a "mode" or "operating mode" or "mode of operation" or "operational mode". This does not exclude the system, apparatus, or device from also being adapted to provide another control mode or multiple other control modes. Similarly, this does not exclude one or more other modes from being performed before and / or after the execution of this mode.

[0055] However, in an embodiment, a control system can be used that is adapted to provide at least a control mode. If other modes are available, the selection of these modes can be performed particularly via a user interface, although other options are also feasible, such as performing the mode according to a sensor signal or a (time) schedule. In an embodiment, the operating mode can also refer to a system, apparatus, or device that can only operate in a single operating mode (i.e., "on", without other adjustability).

[0056] Thus, in an embodiment, the control system can be controlled according to one or more of an input signal of a user interface, a sensor signal (from a sensor), and a timer. The term "timer" can refer to a clock and / or a predetermined time schedule.

[0057] In an embodiment, the control system (in an operating mode) may be configured to control the spectral characteristics of the system light by controlling the polarization of the pump light. Thus, by using the control system to control the polarization of the reflective polarizer, the color point of the system light, in particular the correlated color temperature (CCT), can be controlled. Here, the CCT may be a numerical measure (measured in Kelvin (K)) indicating the color of the light. In addition, with respect to the CCT, the term "white light" and its like terms are well known to those skilled in the art. It particularly relates to light having the following correlated color temperature (CCT): the correlated color temperature is between about 1800K and 20000K, such as between 2000K and 20000K, especially 2700K - 20000K, for general lighting, especially in the range of about 2000K - 7000K, for example in the range of 2700K to 6500K. In addition, in an embodiment, the system light may be white light and may have a correlated color temperature (CCT) in the range of 1800K to 20000K, such as in the range of 1800K to 10000K, especially in the range of 3000K to 1000K. In an embodiment, the system light may be white light having a correlated color temperature selected from the range of 1800K to 6500K. In addition, in an embodiment, the system light may have a color rendering index of at least 70, more particularly at least 80, for example at least 85, especially at least 90.

[0058] In particular, as described above, when pumping with pump light including a first polarization, the ratio of the radiant flux of the pump light including the first polarization to the radiant flux of the luminescent material light (in the system light) may be higher than the ratio of the radiant flux of the pump light including the second polarization to the radiant flux of the luminescent material light (in the system light) when pumping with pump light including the second polarization. This may be because in an embodiment, the reflective polarizer is (substantially) transmissive to the pump light including the first polarization and (substantially) reflective to the pump light including the second polarization.

[0059] By using a polarizer whose polarization can be controlled, the ratio of the first polarization to the second polarization can be controlled. Thus, although it is not necessary to change the radiant flux of the pump light upstream of the polarizer, the ratio of the pump light having the first polarization to the pump light having the second polarization can be controlled.

[0060] Alternatively (or additionally), (at least) two light sources may be applied, where the first light source (optionally in combination with a polarizer) provides pump light having a first polarization; and where the second light source (optionally in combination with a polarizer) provides pump light having a second polarization. Thus, by controlling the ratio of the radiant fluxes of the two light sources, the ratio of the pump light having the first polarization to the pump light having the second polarization can be controlled. Thereby, the polarization of the pump light is controlled.

[0061] In an embodiment, the control system can be configured to control the radiant flux of the pump light (see details below). This can also allow the control system to control the radiant flux of the light.

[0062] As described above, the light generating device can generate pump light including a first polarization and / or a second polarization. In particular, the first polarization and the second polarization can be selected from p-polarization and s-polarization.

[0063] In an embodiment, the primary first solid-state light source can generate (first) polarized pump light. Additionally, in an embodiment, the light generating device can include a secondary first solid-state light source, which can be used to generate pump light with a polarization different from that of the first light source (especially second polarized light). In an embodiment, the primary first solid-state light source and / or the secondary first solid-state light source (each) can include a laser diode. Thus, in an embodiment, two different polarized pump lights can be provided by using two laser diodes.

[0064] Alternatively (or additionally), in an embodiment, a polarizer can be used to polarize the pump light. Thus, in this way, the light generating device can provide pump light with a (desired) polarization. Thus, the light generating device can be used to generate pump light including multiple polarizations (e.g., a combination of both p-polarized pump light and s-polarized pump light). Thus, the first light generating device can include one or more solid-state light sources that provide light as polarized light, or can apply polarization to the light provided by one or more solid-state light sources. In a particular embodiment, the primary first solid-state light source is applied in combination with a (first) polarizer to generate (first) polarized pump light. Additionally, in an embodiment, the light generating device can include a secondary first solid-state light source, which is configured to generate (second) polarized light in combination with (second) polarized light. Thus, in these embodiments, a single light source or including two or more light sources can also be used to provide two different polarized pump lights.

[0065] As can be seen from the above, in a particular embodiment, the first light generating device can include (a) a first pump light source (or "primary first (solid-state) light source") and (b) a second pump light source (or "secondary first (solid-state) light source").

[0066] Accordingly, in an embodiment, the first light generating device may include (a) a first pump light source (or "primary first light source") and (b) a second pump light source (or "secondary first light source"). In particular, the first pump light source may optionally be configured to generate pump light including a first polarization in combination with a first optical device. Additionally, in an embodiment, the second pump light source may optionally be configured to generate pump light including a second polarization in combination with a second optical device. Here, in an embodiment, the first optical device and / or the second optical device may be a polarization filter. The polarization filter may in particular convert unpolarized light into a polarization including a specific orientation. The directional polarization may in particular be controlled by controlling the orientation of the polarization filter. Thus, in this way, pump light including both the first polarization and the second polarization can be provided. Additionally, in an embodiment, the first pump light source and the second pump light source may each include a laser diode. Thus, in some embodiments, the light generating device may further include two laser diodes having different polarizations to provide pump light including both the first polarization and the second polarization. In a particular embodiment, the first light generating device includes (a) a first pump light source and (b) a second pump light source; wherein the first pump light source is optionally configured to generate pump light including a first polarization in combination with a first optical device; and wherein the second pump light source is optionally configured to generate pump light including a second polarization in combination with a second optical device.

[0067] In an embodiment, the first pump light source and / or the second pump light source may include a polarized light source, i.e., the first pump light source and / or the second pump light source may provide polarized light. In such embodiments, an additional polarization filter (such as those described above) is optional.

[0068] As described above, the total radiant flux of the system light may in particular be controlled by a control system. In an embodiment, the control system may further be configured to control the correlated color temperature of the system light by controlling the relative amounts of (a) a first radiant flux of pump light including a first polarization and (b) a second radiant flux of pump light including a second polarization with respect to the total radiant flux of the pump light in an operating mode of the light generating system.

[0069] In particular, in certain embodiments, the control system can be configured to reduce the total radiant flux of the pump light (including the first polarization and / or the second polarization) in the operating mode of the light generation system by increasing the relative amount of the second radiant flux of the pump light including the second polarization relative to the total radiant flux of the pump light. In this way, when reducing the correlated color temperature, the radiant flux may also decrease because more pump light is converted. This can result in a BBL dimming effect: the radiant flux is higher at higher CCTs and lower at lower CCTs. In some embodiments, the system light can include a combination of luminescent material light and pump light (including the first polarization and the second polarization). Thus, in certain embodiments, the control system can be configured to reduce the total radiant flux of the pump light (including the first polarization and / or the second polarization) in the operating mode of the light generation system when increasing the relative amount of the second radiant flux of the pump light including the second polarization relative to the total radiant flux of the pump light. Similarly, the control system can be configured to increase the total radiant flux of the pump light (including the first polarization and / or the second polarization) in the operating mode of the light generation system when increasing the relative amount of the first radiant flux of the pump light including the first polarization relative to the total radiant flux of the pump light.

[0070] Here, the term "first radiant flux" can refer to the radiant flux of the pump light including the first polarization, and the term "second radiant flux" can refer to the radiant flux of the pump light including the second polarization.

[0071] It should be noted that in an embodiment, increasing the second radiant flux of the pump light including the second polarization relative to the total radiant flux of the pump light can be similar to increasing the ratio of the second radiant flux of the pump light including the second polarization to the first radiant flux of the pump light including the first polarization.

[0072] In a particular embodiment, in the first operating mode of the light generation system, the system light includes a first radiant flux ratio X 1 / Y 1 ; wherein in the second operating mode of the light generation system, the system light includes a second radiant flux ratio X 2 / Y 2 where X 1 / Y 1 > X 2 / Y 2 , and more particularly, X 1 / Y 1 ≥ 1.2 * X 2 / Y 2 ; for example, in an embodiment, X 1 / Y 1 ≥ 1.5 * X 2 / Y 2Therefore, in an embodiment, a first radiant flux ratio being greater than a second radiant flux may indicate a relatively high CCT. It can be deduced from the foregoing that, in a particular embodiment, X 2 / X 1 <1 is applicable, such as X 2 / X 1 ≤0.8.

[0073] As described above, in an embodiment, the pump light generated by the first light generating device may be incident on a light emitting body disposed downstream of the light generating device. In particular, the light emitting material is included by the light emitting body.

[0074] The light emitting body may be a layer, such as a self-supporting layer. The light emitting body may also be a coating. The light emitting body may further include a light emitting coating on a support (especially a light transmissive support in a transmissive mode, or a reflective support in a reflective mode). In particular, the light emitting body may be substantially self-supporting. In some embodiments, the light emitting material may be provided as the light emitting body, such as a light emitting single crystal, a light emitting glass, or a light emitting ceramic body. Such a body may be referred to as a "conversion body" or a "light emitting body". In some embodiments, the light emitting body may be a light emitting single crystal or a light emitting ceramic body. For example, in some embodiments, a cerium-containing garnet light emitting material may be provided as a light emitting single crystal or a light emitting ceramic body. In other embodiments, the light emitting body may include a light transmissive body in which the light emitting material is embedded. For example, the light emitting body may include a vitreous body in which the light emitting material is embedded. Alternatively, the glass itself may also be light emitting. In other embodiments, the light emitting body may include a polymeric body in which the light emitting material is embedded.

[0075] The light emitter can have any shape. However, generally, the light emitter can include two substantially parallel faces, thereby defining (the height of the light emitter). In addition, the light emitter can include edge faces that bridge these two substantially parallel faces. The edge faces can be curved in one or two dimensions. The edge faces can be planar. The cross-section of the light emitter can be rectangular or circular, but can also be other shapes, such as hexagonal, octagonal, etc. Thus, the cross-section of the light emitter can be circular, oval, square, or non-square rectangular. In some embodiments, the light emitter can have an n-sided cross-section, where n is at least 3, such as 4 (square or rectangular cross-section), 5 (pentagonal cross-section), 6 (hexagonal cross-section), 8 (octagonal cross-section), or higher. These two substantially parallel faces can also be referred to as "main faces" because they can particularly provide the largest external area of the light emitter. Perpendicular to the above cross-section can be another cross-section, which can be rectangular in some embodiments. Thus, the light emitter can, for example, have a cubic shape, a (non-cubic) cuboid shape, an n-prism shape with n at least 5 (such as a pentaprism, a hexagonal prism), and a cylindrical shape. However, other shapes are also possible. In particular, the light emitter can have a cuboid shape, a cylindrical shape, or an n-prism shape with n being 6 or 8.

[0076] In an embodiment, the light emitter (or "body") has a width or length (W1 or L1) or diameter (D) of the lateral dimension and a thickness or height (H1). In an embodiment, (i) D≥H1 or (ii) and W1≥H1 and / or L1≥H1. The light emitter can be transparent or light-scattering. In an embodiment, the light emitter can include a ceramic light-emitting material. In a particular embodiment, L1≤10 mm, such as in particular L1≤5 mm, more particularly L1≤3 mm, and most particularly L1≤2 mm. In a particular embodiment, W1≤10 mm, such as in particular W1≤5 mm, more particularly W1≤3 mm, and most particularly W1≤2 mm. In a particular embodiment, H1≤10 mm, such as in particular H1≤5 mm, more particularly H1≤3 mm, and most particularly H1≤2 mm. In a particular embodiment, D≤10 mm, such as in particular D≤5 mm, more particularly D≤3 mm, and most particularly D≤2 mm. In a particular embodiment, the thickness of the body can be in the range of 50 μm - 1 mm. In addition, the lateral dimension (width / diameter) of the body can be in the range of 100 μm - 10 mm. In a further particular embodiment, (i) D>H1 or (ii) W1>H1 and L1>H1. In particular, the lateral dimension (such as length, width, and diameter) is at least 2 times larger than the height, for example, at least 5 times. In a particular embodiment, the light emitter has a first length L1, a first height H1, and a first width W1, where H1≤0.5*L1 and H1≤0.5*W1.

[0077] In an embodiment, the light emitter may include a first face, a second face, and a side face bridging the first and second faces. The first and second faces may also be referred to as main faces. In the case of a cylindrical shape, the side face may be a single face. In the case of a cuboid, the side face may include four facets. If it is a hexagonal prism, the side face may include six facets.

[0078] In particular, the light emitter may be configured in a transmission mode. In the transmission mode, the source light may be relatively easily mixed with the luminescent material light, which can be used to generate a desired spectral power distribution. In the reflection mode, thermal management may be easier because a large portion of the luminescent material can be in thermal contact with a heat conducting element (such as a heat sink or a heat spreader). Thus, in an embodiment, if any device light escapes from the system, this may only be via transmission through the light emitter.

[0079] In an embodiment, a portion of the pump light incident on the light emitter may be transmitted, and a portion of the pump light may be converted into luminescent material light. Thus, in an embodiment, the light emitter may be transparent. In particular, the light emitter may be at least partially transparent to the pump light. Thus, in an embodiment, the light emitter may include a ceramic body or a single crystal.

[0080] In particular, the scattering may be relatively low. In an embodiment, at most 30% (such as at most 20%), more particularly at most 10% of the pump light may undergo scattering (assuming a single pass and the optical axis is perpendicular to the (main) face of the light emitter (see also above)). Embodiments of the luminescent material will be described below.

[0081] In an embodiment, 5% - 95%, such as 10% - 90%, such as 20 - 85% of the total radiant flux of the pump light may be absorbed by the light emitter in a single pass through the light emitter. In a particular embodiment, the light emitter may be configured such that (under perpendicular illumination of the pump light) the radiant flux in the range of 30% - 80% of the total radiant flux of the pump light may be absorbed by the light emitter in a single pass through the light emitter. Additionally, in an embodiment, 30% - 70%, such as 30% - 60%, such as 30% - 50% of the total radiant flux of the pump light may be absorbed by the light emitter in a single pass through the light emitter. The absorbed pump light may be converted into luminescent material light.

[0082] The term "luminescent material" particularly refers to a material capable of converting a first radiation (especially one or more of UV radiation and blue radiation) into a second radiation. Generally, the first radiation and the second radiation have different spectral power distributions. Thus, in addition to the term "luminescent material", the terms "luminescent converter" or "converter" can also be applied. Generally, the second radiation has a spectral power distribution at a larger wavelength than the first radiation, which is the so-called down-conversion case. However, in a specific embodiment, the second radiation has a spectral power distribution of intensity at a smaller wavelength than the first radiation, which is the so-called up-conversion case.

[0083] In an embodiment, the "luminescent material" can particularly refer to a material capable of converting radiation into, for example, visible light and / or infrared light. For example, in an embodiment, the luminescent material is capable of converting one or more of UV radiation and blue radiation into visible light. In a specific embodiment, the luminescent material can also convert radiation into infrared radiation (IR). Thus, when excited by radiation, the luminescent material emits radiation. Generally, the luminescent material will be a down-converter, i.e., converting radiation of a smaller wavelength into radiation of a larger wavelength (λ ex <λ em ), but in a specific embodiment, the luminescent material can include an up-converting luminescent material, i.e., converting radiation of a larger wavelength into radiation of a smaller wavelength (λ ex <λ em ).

[0084] In an embodiment, the term "luminescence" can refer to phosphorescence. In an embodiment, the term "luminescence" can also refer to fluorescence. The term "emission" can also be applied instead of the term "luminescence". Thus, the terms "first radiation" and "second radiation" can refer to excitation radiation and emission (radiation), respectively. Similarly, the term "luminescent material" can refer to phosphorescence and / or fluorescence in an embodiment.

[0085] The term "luminescent material" can also refer to a variety of different luminescent materials. Some possible examples of luminescent materials will be listed below. Thus, in a specific embodiment, the "luminescent material" can also refer to a luminescent material composition. The term "phosphor" can also be applied instead of the "luminescent material". These terms are well-known to those skilled in the art.

[0086] In an embodiment, the luminescent material is selected from garnets and nitrides, especially materials doped with trivalent cerium or divalent europium. The term "nitride" can also refer to oxynitrides or silicon oxynitrides, etc. Alternatively or additionally, the luminescent material can also be selected from silicates, especially materials doped with divalent europium.

[0087] In a specific embodiment, the luminescent material comprises A 3 B 5 O 12: Luminescent materials of the Ce type, wherein A in the examples includes one or more of Y, La, Gd, Tb, and Lu, particularly (at least) one or more of Y, Gd, Tb, and Lu, and wherein B in the examples includes one or more of Al, Ga, In, and Sc. In particular, A may include one or more of Y, Gd, and Lu, such as particularly one or more of Y and Lu. In particular, B may include one or more of Al and Ga, more particularly at least includes Al, such as substantially completely includes Al. Therefore, particularly suitable luminescent materials are cerium-containing garnet materials. Examples of garnets particularly include A 3 B 5 O 12 garnets, wherein A includes at least yttrium or lutetium, and wherein B includes at least aluminum. Such garnets may be doped with cerium (Ce), praseodymium (Pr), or a composition of cerium and praseodymium; but particularly doped with cerium. B may particularly include aluminum (Al); however, in addition to aluminum, B may also partially contain gallium (Ga) and / or scandium (Sc) and / or indium (In), particularly up to about 20% of B, more particularly up to about 10% of B (i.e., B ions are substantially composed of 90% or more by mole percentage of aluminum and 10% or less by mole percentage of one or more of gallium, scandium, and indium); B may particularly include up to about 10% of gallium. In another variant, B and O may be at least partially replaced by silicon (Si) and nitrogen (N). Element A may particularly be selected from the group consisting of yttrium (Y), gadolinium (Gd), terbium (Tb), and lutetium (Lu). In addition, particularly, the content of Gd and / or Tb is only up to about 20% of A. In a specific example, the garnet luminescent material includes (Y 1-x Lu x ) 3 B 5 O 12 :Ce, where x is equal to or greater than 0 and equal to or less than 1. The term ":Ce" means that a part of the metal ions in the luminescent material (i.e., in the garnet: a part of the "A" ions) is replaced by Ce. For example, in (Y 1-x Lu x ) 3 Al 5 O 12 :Ce, a part of Y and / or Lu is replaced by Ce. This is known to those skilled in the art. The amount of Ce replacing A generally does not exceed 10%; generally, the Ce concentration (relative to A) is in the range of 0.1% to 4%, particularly in the range of 0.1% to 2%. Assuming the Ce content is 1% and the Y content is 10%, the complete and correct molecular formula can be (Y 0.1 Lu 0.89 Ce 0.01 ) 3 Al 5 O12 It is known to those skilled in the art that Ce in garnet is substantially or only in the trivalent state.

[0088] In an embodiment, the luminescent material thus comprises A 3 B 5 O 12 , wherein in a particular embodiment, up to 10% of B-O can be replaced by Si-N.

[0089] In a particular embodiment, the luminescent material comprises (Y x1-x2-x3 A' x2 Ce x3 ) 3 (Al y1-y2 B' y2 ) 5 O 12 , where x1 + x2 + x3 = 1, where x3 > 0, where 0 < x2 + x3 ≤ 0.2, where y1 + y2 = 1, where 0 ≤ y2 ≤ 0.2, where A' comprises one or more elements selected from the group consisting of lanthanide elements, and where B' comprises one or more elements selected from the group consisting of Ga, In, and Sc. In some embodiments, x3 is selected from the range of 0.001 - 0.1. In the present invention, in particular, x1 > 0, such as > 0.2, for example at least 0.8. Y-containing garnet can provide a suitable spectral power distribution.

[0090] In a particular embodiment, up to 10% of B-O can be replaced by Si-N. Here, B in B-O refers to one or more of Al, Ga, In, and Sc (and O refers to oxygen); in a particular embodiment, B-O can refer to Al-O. As described above, in a particular embodiment, x3 can be selected from the range of 0.001 - 0.04. In particular, such luminescent materials can have a suitable spectral distribution (but see below), relatively high efficiency, relatively high thermal stability, and allow a high CRI (optionally in combination with the light of other light sources described herein). Thus, in a particular embodiment, A can be selected from the group consisting of Lu and Gd. Alternatively or additionally, B can include Ga. Thus, in an embodiment, the luminescent material comprises (Y x1-x2-x3 (Lu,Gd) x2 Ce x3 ) 3 (Al y1-y2 Ga y2 ) 5 O 12 , where Lu and / or Gd can be available. More particularly, x3 is selected from the range of 0.001 - 0.1, where 0 < X 2 + x3 ≤ 0.1, and where 0 ≤ Y 2≤0.1. Additionally, in certain embodiments, up to 1% of B-O can be replaced by Si-N. Here, the percentages refer to moles (as is known in the art); for example, see EP3149108. In more specific embodiments, the luminescent material comprises (Y x1-x3 Ce x3 ) 3 Al 5 O 12 , where x1 + x3 = 1, and 0 < x3 ≤ 0.2, such as 0.001 - 0.1.

[0091] In certain embodiments, the light generating device can only comprise a luminescent material selected from the cerium-containing garnet type. In more specific embodiments, the light generating device comprises a single type of luminescent material, such as (Y x1-x2-x3 A’ x2 Ce x3 ) 3 (Al y1-y2 B’ y2 ) 5 O 12 . Thus, in certain embodiments, the light generating device comprises a luminescent material, wherein at least 85 wt%, even more particularly at least about 90 wt%, such as even more particularly at least about 95 wt% of the luminescent material comprises (Y x1-x2-x3 A’ x2 Ce x3 ) 3 (Al y1-y2 B’ y2 ) 5 O 12 . Here, where A’ comprises one or more elements selected from the group consisting of lanthanide elements, and where B’ comprises one or more elements selected from the group consisting of Ga, In, and Sc, where x1 + x2 + x3 = 1, where x3 > 0, where 0 < x2 + x3 ≤ 0.2, where y1 + y2 = 1, where 0 ≤ y2 ≤ 0.2. In particular, x3 is selected from the range of 0.001 - 0.1. It should be noted that in some embodiments, x2 = 0. Alternatively or additionally, in some embodiments, y2 = 0.

[0092] In certain embodiments, A can particularly comprise at least Y, and B can particularly comprise at least Al.

[0093] Alternatively or additionally, where the luminescent material can comprise A 3 Si 6 N 11 :Ce 3+ type luminescent material, where A comprises one or more of Y, La, Gd, Tb, and Lu, such as comprising one or more of La and Y in embodiments.

[0094] In an embodiment, the luminescent material may alternatively or additionally include MS:Eu 2+ and / or M 2 Si 5 N 8 :Eu 2+ and / or MAlSiN 3 :Eu 2+ and / or Ca 2 AlSi 3 O 2 N 5 :Eu 2+ and the like, where M includes one or more of Ba, Sr, and Ca, especially including at least Sr in an embodiment. Thus, in an embodiment, the luminescent material may include one or more selected from the group consisting of (Ba,Sr,Ca)S:Eu, (Ba,Sr,Ca)AlSiN 3 :Eu and (Ba,Sr,Ca) 2 Si 5 N 8 :Eu. In these compounds, europium (Eu) is substantially or only divalent and replaces one or more of the indicated divalent cations. Generally, the content of Eu will not be greater than 10% of the cations; its amount relative to the amount of the cations it replaces will especially be in the range of about 0.5% to 10%, more especially in the range of about 0.5% to 5%. The term ":Eu" means that a part of the metal ions is replaced by Eu (replaced by Eu 2+ in these examples). For example, assuming the content of Eu in CaAlSiN 3 :Eu is 2%, the correct chemical formula may be (Ca 0.98 Eu 0.02 )AlSiN 3 . Divalent europium usually replaces 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 expressed as MS:Eu, where M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr), and calcium (Ca); in particular, in this compound, M includes calcium or strontium, or calcium and strontium, more especially including calcium. Here, Eu is introduced and Eu replaces at least a part of M (i.e., one or more of Ba, Sr, and Ca). In addition, the material (Ba,Sr,Ca) 2 Si 5 N 8 :Eu can also be expressed as M 2 Si 5 N 8: Eu, where M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr), and calcium (Ca); in particular, M in this compound includes Sr and / or Ba. In another specific embodiment, M consists of Sr and / or Ba (regardless of the presence of Eu), especially 50% to 100%, more especially 50% to 90% of Ba, and 50% to 0%, especially 50% to 10% of Sr, such as Ba 1.5 Sr 0.5 Si 5 N 8 : Eu (i.e., 75% Ba; 25% Sr). Eu is introduced here and replaces at least a part of M (i.e., one or more of Ba, Sr, and Ca). Similarly, the material (Ba,Sr,Ca)AlSiN 3 : Eu can also be expressed as MAlSiN 3 : Eu, where M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr), and calcium (Ca); in particular, M in this compound includes calcium or strontium, or calcium and strontium, more especially includes calcium. Eu is introduced here and replaces at least a part of M (i.e., one or more of Ba, Sr, and Ca). It is known to those skilled in the art that Eu in the above luminescent materials is basically or only in the divalent state.

[0095] In an embodiment, the red luminescent material may include one or more materials selected from the group consisting of (Ba,Sr,Ca)S:Eu, (Ba,Sr,Ca)AlSiN 3 : Eu and (Ba,Sr,Ca) 2 Si 5 N 8 : Eu. In these compounds, europium (Eu) is basically or only divalent and replaces one or more of the indicated divalent cations. Generally, the content of Eu is not greater than 10% of the cations; its amount present is especially in the range of about 0.5% to 10% relative to the cations it replaces, more especially in the range of about 0.5% to 5%. The term ":Eu" means that a part of the metal ions is replaced by Eu (Eu 2+ in these examples). For example, assuming that CaAlSiN 3 : Eu contains 2% Eu, the correct chemical formula should be (Ca 0.98 Eu 0.02 )AlSiN 3 . Divalent europium usually replaces divalent cations, such as the above divalent alkaline earth cations, especially Ca, Sr, or Ba.

[0096] The material (Ba,Sr,Ca)S:Eu can also be expressed as MS:Eu, where M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr), and calcium (Ca); in particular, M in this compound includes calcium or strontium, or calcium and strontium, and more particularly calcium. Here, Eu is introduced and replaces at least a part of M (i.e., one or more of Ba, Sr, and Ca).

[0097] In addition, the material (Ba,Sr,Ca) 2 Si 5 N 8 :Eu can also be expressed as M 2 Si 5 N 8 :Eu, where M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr), and calcium (Ca); in particular, M in this compound includes Sr and / or Ba. In another specific embodiment, M consists of Sr and / or Ba (regardless of the presence of Eu), especially 50% to 100%, more especially 50% to 90% of Ba, and 50% to 0%, especially 50% to 10% of Sr, such as Ba 1.5 Sr 0.5 Si 5 N 8 :Eu (i.e., 75% Ba; 25% Sr). Here, Eu is introduced and replaces at least a part of M, i.e., one or more of Ba, Sr, and Ca.

[0098] Similarly, the material (Ba,Sr,Ca)AlSiN 3 :Eu can also be expressed as MAlSiN 3 :Eu, where M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr), and calcium (Ca); in particular, M in this compound includes calcium or strontium, or calcium and strontium, and more particularly calcium. Here, Eu is introduced and replaces at least a part of M (i.e., one or more of Ba, Sr, and Ca).

[0099] Eu in the above luminescent materials is substantially or only in the divalent state, which is known to those skilled in the art.

[0100] The blue luminescent material can include YSO (Y 2 SiO 5 :Ce 3+ ) or a similar compound, or BAM (BaMgAl 10 O 17 :Eu 2 + ) or a similar compound.

[0101] The term "luminescent material" in this text particularly relates to inorganic luminescent materials.

[0102] Optionally or additionally, other luminescent materials can also be applied. For example, quantum dots and / or organic dyes can be applied, and they can optionally be embedded in a transmissive matrix, such as a polymer (such as PMMA or polysiloxane, etc.).

[0103] Quantum dots are small crystals of semiconductor materials, the width or diameter of which is usually only a few nanometers. When excited by incident light, quantum dots emit light of a color determined by the size and material of the crystal. Therefore, light of a specific color can be generated by adjusting the size of the dots. Most known quantum dots emitting in the visible light range are based on cadmium selenide (CdSe), the shell of which is such as cadmium sulfide (CdS) and zinc sulfide (ZnS). Cadmium-free quantum dots can also be used, such as indium phosphide (InP), copper indium sulfide (CuInS 2 ) and / or silver indium sulfide (AgInS 2 ). The emission band of quantum dots is very narrow and thus shows saturated colors. In addition, the emission color can be easily adjusted by adjusting the size of the quantum dots. Any type of quantum dots known in the art can be used in the present invention. However, for environmental safety and concern reasons, it may be preferable to use cadmium-free quantum dots or quantum dots with a very low cadmium content at least.

[0104] In addition to quantum dots, other quantum confinement structures can also be used. In the context of this application, the term "quantum confinement structure" should be understood as, for example, quantum wells, quantum dots, quantum rods, tripods, tetrapods or nanowires, etc.

[0105] Organic phosphors can also be used. Examples of suitable organic phosphor materials are organic luminescent materials based on perylene derivatives, such as the compounds sold by BASF under the name. Examples of suitable compounds include but are not limited to red F305, orange F240, yellow F083 and F170.

[0106] Different luminescent materials may have different spectral power distributions of the light of the corresponding luminescent materials. Alternatively or additionally, these different luminescent materials can particularly have different color points (or dominant wavelengths).

[0107] As described above, other luminescent materials are also possible. Thus, in certain embodiments, the luminescent material is selected from divalent europium nitrides, divalent europium oxynitrides, divalent europium silicates, cerium-containing garnets, and quantum structures. Quantum structures can, for example, include quantum dots or quantum rods (or other quantum-type particles) (see above). Quantum structures can also include quantum wells. Quantum structures can also include photonic crystals.

[0108] In addition, in an embodiment, the light generation system can include additional optical elements that modify the quality or characteristics of the provided system light. In particular, the light generation system can include an optical element downstream of the reflective polarizer. Such an optical element can be referred to as a downstream optical element. In an embodiment, the downstream optical element can include one or more of a depolarizer, a beam shaping element, a lens, and a diffuser. In an embodiment, the depolarizer can eliminate the polarization of the system light such that the system light no longer has a single polarization orientation (or direction). In addition, the downstream optical element can include a beam shaping element, such as a hollow reflector or a collimator body, which can help provide a parallel, divergent, or even focused beam. In addition, the downstream optical element can include a diffuser, which can provide diffused system light. The term "optical element" or "downstream optical element" can also refer to multiple such elements, respectively.

[0109] In a further embodiment, additional optical elements that are reflective for the luminescent material light can be configured upstream of the luminescent body. Thus, the luminescent material light reflected upstream of the luminescent body can undergo a subsequent reflection at the optical element and is thus reflected back to the luminescent body. In addition, the luminescent body can be particularly transmissive for the luminescent material light. Thus, in this way, the amount of luminescent material light coupled out from the light generation system (i.e., the amount of luminescent material light included in the system light) can be increased. Such additional optical elements, particularly reflectors, can be reflective for the luminescent material light and transmissive for the pump light. This can be achieved by using a dichroic mirror or a (dichroic) mirror with a (pin)hole for the pump light (see also below).

[0110] Accordingly, in an embodiment, pump light can be incident on a luminescent body and thus be converted into luminescent material light. However, a portion of the luminescent material light may be reflected in the upstream direction. Accordingly, a portion of the luminescent material light may not be coupled out from the light generation system. In an embodiment, this situation can be alleviated by disposing a reflective element upstream of the luminescent body. Accordingly, in an embodiment, the light generation system may further include a first reflector that is configured downstream of the first light generation device and upstream of the luminescent body. In particular, the first reflector can be reflective for the luminescent material light and transmissive for the pump light. Accordingly, in an embodiment, the pump light incident on the first reflector can be transmitted through the first reflector to the luminescent body. However, in an embodiment, the first reflector can be reflective for the luminescent material light. Accordingly, in an embodiment, the luminescent material light reflected upstream may be reflected back downstream. Accordingly, in this way, the intensity of the luminescent material light included in the system light can be particularly increased. In an embodiment, the first reflector may include a dichroic filter. A dichroic filter is a filter (or reflector) that is transmissive for light of a specific wavelength and reflective for light of other wavelengths. In a particular embodiment, the light generation system includes a first reflector that is configured downstream of the first light generation device and upstream of the luminescent body, wherein the first reflector is reflective for the luminescent material light and transmissive for the pump light (wherein the first reflector includes a dichroic filter). Additionally or alternatively, in an embodiment, the first reflector may include a pinhole. In particular, the pinhole can be a small opening in the first reflector through which a narrow beam of the pump light can propagate without contacting the first reflector. Accordingly, in this way, the pump light can be incident on the luminescent body without being blocked by the first reflector. Further, in an embodiment, the pinhole can be small enough such that the luminescent material light reflected upstream by the luminescent body can subsequently be reflected by the first reflector (with minimal loss of the luminescent material light through the pinhole). In a particular embodiment, the first reflector includes a first pinhole, wherein the first light generation device is configured to irradiate the luminescent body with pump light via the first pinhole.

[0111] In an embodiment, the spectral power distribution of the system light can be changed by configuring an additional light generating device. In an embodiment, the light generating system may further include a second light generating device configured to generate second device light having a spectral power distribution different from that of the pump light and different from that of the luminescent material light. In particular, the second light generating device may include a second solid-state light source selected from the group including superluminescent diodes and laser diodes. It should be noted that, in an embodiment, a variety of different combinations of configuring the second light generating device can be employed. In other embodiments, the second light generating device may include two or more different second solid-state light sources. In some embodiments, the second device light can be directly coupled out without interacting with the luminescent body or the reflective polarizer. Thus, in this way, the second device light can particularly bypass the luminescent body or the reflective polarizer. However, in other embodiments, the second device light can also be provided after interacting (especially in terms of reflection and / or transmission) with the luminescent body and / or the reflective polarizer.

[0112] In an embodiment, the second light generating device can be configured such that at least a portion of its second device light bypasses the luminescent body and the reflective polarizer. In an embodiment, this can be achieved by an optical element (such as a dichroic filter) that is transmissive for the pump light (and the luminescent material light) but reflective for the second device light. Thus, in an embodiment, by configuring the optical element downstream of the luminescent body and the reflective polarizer, the optical element can facilitate the transmission of the pump light and the luminescent material light. However, the second light generating device can be particularly configured such that the second device light can be reflected in the direction of the pump light, thereby bypassing the luminescent body and the reflective polarizer.

[0113] Alternatively, in an embodiment, the second light generating device can be configured upstream of the luminescent body and the reflective polarizer. Additionally, in such an embodiment, the second device light can be coupled out of the light generating system without bypassing the luminescent body and the optical reflector. In particular, the luminescent body can transmit at least a portion of the second device light. Additionally, the reflective polarizer can be particularly transmissive for at least a portion of the second device light. This is particularly advantageous when the second device light also includes first polarized light.

[0114] Note that, as described above, the control system can in particular control the operation of the first light generation device. Similarly, in an embodiment, the control system can also control the operation of the second light generation device. In particular, the radiant flux of the second solid-state light source can also be controlled by the control system. Thus, in this way, in particular, one or more of the spectral power distribution, radiant flux, and CCT of the system light can also be further controlled by controlling the second light generation device. Thus, in a particular embodiment, the light generation system can also include a second light generation device configured to generate second device light having a spectral power distribution different from the pump light and different from the luminescent material light; wherein the second light generation device includes a second solid-state light source selected from the group including superluminescent diodes and laser diodes; wherein the control system is configured to control the spectral characteristics of the system light by controlling the polarization of the pump light and by controlling the second light generation device.

[0115] Thus, in an embodiment including a first reflector, the first reflector can include a second pinhole. In particular, the second light generation device can be configured to irradiate the luminescent body with the second device light via the second pinhole. In this way, the second device light can be incident on the luminescent body without contacting the first reflector (as described above).

[0116] In an embodiment, the second device light can include polarized light having a first polarization.

[0117] In an embodiment, the first light generation device can be configured to generate pump light having a wavelength in the blue wavelength range. Alternatively or additionally, in such embodiments, the second device light can include spectral intensity in one or more of the green wavelength range and the red wavelength range. Additional features related to the wavelength range of the pump light will be discussed further below. Thus, in an embodiment, the first light generation device can be configured to generate blue pump light. In an embodiment, the second light generation device can be configured to generate red light. In an embodiment, the second light generation device can be configured to generate green light. In an embodiment, the primary second light generation device can be configured to generate green light and the secondary second light generation device can be configured to generate red light.

[0118] The light generation system may include other optical devices. The term "optical device" may particularly refer to (one or more) optical elements. Thus, the terms "optical device" and "optical element" may refer to the same article. An optical device may include one or more mirrors, reflectors, collimators, lenses, prisms, diffusers, phase plates, polarizers, diffractive elements, gratings, dichroic mirrors, arrays of one or more of the above elements, etc. Alternatively or additionally, the term "optical device" may refer to a holographic element or a hybrid rod. In an embodiment, the optical device may include one or more beam expander optical devices and zoom lens optical devices. For examples of optical devices, see above. In an embodiment, the optical device may include an integrator, such as a "Kohler integrator" (or " integrator").

[0119] The optical device may include a beam shaping element, such as an optical element selected from the group consisting of a lens, a lens assembly, a collimator, and a hollow reflector. Here, a lens (such as a biconvex lens, a plano-convex lens, a biconcave lens, etc.) may include a transparent material that can shape a light beam by refraction. In an embodiment, the lens assembly may in particular be a combination of one or more lenses. A collimator and / or a hollow reflector may in particular shape a light beam to provide a parallel light beam. Thus, in this way, the first optical device and / or the second optical device can facilitate the beam shaping of the pump light. The optical device may be configured to shape the system light beam. However, the optical device may also be used to shape the light beam from the first light generation device.

[0120] The term "violet light" or "violet emission" particularly refers to light having a wavelength in the range of about 380 nm - 440 nm. The term "blue light" or "blue emission" particularly refers to light having a wavelength in the range of about 440 nm - 495 nm (including some violet and cyan hues). The term "green light" or "green emission" particularly refers to light having a wavelength in the range of about 495 nm - 570 nm. The term "yellow light" or "yellow emission" particularly refers to light having a wavelength in the range of about 570 nm - 590 nm. The term "orange light" or "orange emission" particularly refers to light having a wavelength in the range of about 590 nm - 620 nm. The term "red light" or "red emission" particularly refers to light having a wavelength in the range of about 620 nm - 780 nm. The term "pink light" or "pink emission" refers to light having blue and red components. The term "cyan" may refer to one or more wavelengths selected from the range of about 490 nm - 520 nm. The term "amber" may refer to one or more wavelengths selected from the range of about 585 nm - 605 nm, such as about 590 nm - 600 nm. The term "visible light" particularly refers to light selected from the wavelength range of 380 nm - 780 nm.

[0121] The light generation system can be part of or applied to the following: office lighting systems, home application systems, store lighting systems, domestic lighting systems, accent lighting systems, spotlighting systems, theater lighting systems, fiber optic applications, projection systems, self-luminous display systems, pixelated display systems, segmented display systems, warning sign systems, medical lighting applications, indicator sign systems, decorative lighting systems, portable systems, automotive applications, (outdoor) road lighting systems, city lighting systems, greenhouse lighting systems, horticultural lighting, digital projection, or LCD backlighting. The light generation system (or luminaire) can be part of or applied to systems such as, for example, optical communication systems or disinfection systems.

[0122] In another aspect, the present invention can provide a lighting device selected from the group consisting of the following items including the lighting system: lamps, luminaires, projector devices, disinfection devices, photoreactors, and optical wireless communication devices. The luminaire may further include a housing, optical elements, a light shielding grille, and so on... The lighting device may further include a housing surrounding the lighting generation system. The lighting device may include a light window or a housing opening within the housing through which light can escape from the housing. In another aspect, the present invention further provides a projection device including the lighting generation system defined herein. In particular, the projection device or "projector" or "image projector" can be an optical device that projects an image (or moving image) onto a surface (such as, for example, a projection screen). The projection device may include one or more lighting generation systems described herein. Thus, in one aspect, the present invention also provides a lighting device selected from the group of lamps, luminaires, projector devices, disinfection devices, photoreactors, and optical wireless communication devices, which includes the lighting generation system defined herein. The lighting device may include a housing or carrier configured to accommodate or support one or more elements of the lighting generation system. For example, in some embodiments, the lighting device may include a housing or carrier configured to accommodate or support a light generation device. In other embodiments, the housing may be configured to accommodate or support one or more optical elements, such as a first reflector, a light emitter, a reflective polarizer, and the like. The luminaire may further include a light chamber, optical elements, a light shielding grille, and so on. The lamp or luminaire may further include a light chamber surrounding the lighting system. The lamp or luminaire may include a light window (or radiant exit window) or a light chamber opening within the light chamber through which the system light can escape from the light chamber. In particular, the lighting device may include a laser-phosphor-based stage lighting device that provides CCT control and includes the light generation system described herein. In addition, the present invention can also provide a lighting device for stage lighting, stadium lighting, or traffic infrastructure lighting. BRIEF DESCRIPTION OF THE DRAWINGS

[0123] Reference will now be made to the accompanying schematic drawings to describe embodiments of the present invention by way of example only, where corresponding reference signs denote corresponding parts, and where:

[0124] Figure 1 An embodiment of a light generation system is schematically shown,

[0125] Figures 2a - 2d schematically depict embodiments of different configurations including the light generation system 1000, and

[0126] Figure 3 An embodiment of an application is schematically depicted.

[0127] The schematic drawings are not necessarily drawn to scale. Detailed Description

[0128] Figure 1 An embodiment of the light generation system 1000 is schematically shown, which includes a first light generation device 2100, a light emitter 210, a reflective polarizer 500, and a control system 300.

[0129] In an embodiment, the first light generation device 2100 may be configured to generate pump light 2101 with controllable polarization. In particular, the polarization of the generated pump light 2101 can be changed, and the degree of this change can be controlled (in particular by the control system 300). In an embodiment, the polarization can be controllable between a first polarization and a second polarization. Further, in an embodiment, the first light generation device 2100 may include a first solid - state light source 10. In particular, the solid - state light source 10 can be selected from the group including superluminescent diodes and laser diodes. Thus, in this way, these light sources can provide a narrow beam in an embodiment. In an embodiment, the solid - state light source 10 can generate source light 11.

[0130] In an embodiment, the lumophore 210 may be configured downstream of the solid-state light source 10. Thus, in this way, the generated pump light 2101 escaping from the light generation device 2100 (including the solid-state light source 10) may be incident on the lumophore 210. In an embodiment, the lumophore 210 may include a luminescent material 200. The characteristics of the luminescent material 200 used in the embodiment have been further discussed above. Essentially, the lumophore 210 may convert a portion of the generated pump light 2101 into luminescent material light 201. Thus, in an embodiment, the lumophore 210 may be configured to (a) transmit at least a portion of the pump light 2101 (including the first polarization and / or the second polarization), and (b) convert at least a portion of the pump light 2101 (including the first polarization and / or the second polarization) into luminescent material light 201. In summary, the light generation device 2100 may generate pump light 2101, which may then be incident on the lumophore 210 and undergo partial conversion such that the light provided downstream of the lumophore 210 may include pump light 2101 and luminescent material light 201.

[0131] In an embodiment, the lumophore may include a first face, a second face, and a side face bridging the first face and the second face. The first face may be configured upstream of the second face. In particular, the first face may be directed towards the first light generation device 2100. Additionally, the second face may thus be configured downstream of the first face. In particular, the second face may be directed towards the reflective polarizer 500. In particular, the light transmitted through the lumophore 210 (e.g., pump light 2101) may escape particularly via the second face. Additionally, the light reflected by the lumophore 210 may escape particularly from the first face. In some embodiments, some of the emitted light may escape via the side face of the lumophore 210.

[0132] Furthermore, in an embodiment, the reflective polarizer 500 may be configured downstream of the lumophore 210. In particular, the reflective polarizer 500 may be transmissive for at least a portion of the luminescent material light 201. It should be noted that, in an embodiment, the reflective polarizer 500 may have a higher transmittance for the pump light 2101 including the first polarization compared to the pump light 2101 including the second polarization. Additionally, in an embodiment, the reflective polarizer 500 may have a lower reflectance for the pump light 2101 including the first polarization compared to the pump light 2101 including the second polarization. Additionally, the reflective polarizer 500 may be at least partially transmissive for the luminescent material light 201. Thus, in an embodiment, the light provided downstream of the reflective polarizer 500 may include a combination of pump light 2101 and luminescent material light 201. Thus, the light generation system 1000 may be configured to generate system light 1001, where the system light 1001 may include pump light 2101 and luminescent material light 201.

[0133] In an embodiment, the control system 300 may be configured to control the spectral characteristics of the system light 1001 by controlling the polarization of the pump light 2101. Additionally, the control system 300 may be configured to control the system light 1001 based on one or more of an input signal from a user interface, a sensor signal (from a sensor), and a timer. In an embodiment, the control system 300 may be configured to control the system light 1001 by controlling the light generating device 2100, such as by controlling one or more of the polarization of the pump light 2101 and the radiant flux of the pump light 2101.

[0134] Specifically, in a particular embodiment, the control system 300 may be configured to, in an operating mode of the light generating system 1000, decrease the total radiant flux of the pump light 2101 (including the first polarization and / or the second polarization) when increasing the relative amount of the second radiant flux of the pump light 2101 including the second polarization with respect to the total radiant flux of the pump light 2101. In such an operating mode in an embodiment, first, the total radiant flux of the pump light 2101 may be decreased. Thus, in an embodiment, the light generating system 1000 may provide a feature of dimming the system light 1001. Additionally, the total radiant flux of the pump light 2101 may be decreased, thereby increasing the ratio of the second radiant flux (of the pump light 2101) to the first radiant flux (of the pump light 2101). Thus, in this way, in an embodiment, the spectral power distribution of the light generating system 1000 may be controlled.

[0135] In an embodiment, a portion of the light incident on the luminary 210 may be absorbed. A portion of the incident light may in particular (also) be scattered by the luminary 210, and a portion of the incident light may in particular be transmitted. Thus, in an embodiment, the luminary 210 may at least partially transmit the pump light 2101. Thus, in an embodiment, the luminary 210 may be at least (partially) transparent. Additionally, in an embodiment, the luminary 210 may include a ceramic body or a single crystal.

[0136] In an embodiment, the first polarization and the second polarization may be selected from p-polarization and s-polarization. The light may in particular be polarized in different directions, where s-polarization refers to light polarized in a component direction perpendicular to the plane of polarization, and p-polarization refers to light polarized in a component direction parallel to the plane of polarization. In an embodiment, the first solid-state light source 10 may include a laser diode. It should be noted that, in an embodiment, the laser diode light may be partially polarized or fully polarized.

[0137] In addition, in an embodiment, the control system 300 may be configured to control the correlated color temperature of the system light 1001 in the operating mode of the light generation system 1000 by controlling (a) the first radiant flux of the pump light 2101 including a first polarization and (b) the relative amount of the second radiant flux of the pump light 2101 including a second polarization with respect to the total radiant flux of the pump light 2101. Thus, in this way, by changing the ratio of the first radiant flux of the pump light 2101 to the second radiant flux of the pump light 2101, the CCT of the system light 1001 can be controlled in particular. See also FIGS. 2a-2d.

[0138] In an embodiment, the light generation system 1000 may further include a downstream optical element 580, which includes one or more of a depolarizer, a beam shaping element, a lens, and a diffuser. In particular, the downstream optical element 580 may be configured downstream of the reflective polarizer 500. In an embodiment, the light incident on the depolarizer may disrupt the polarization of the light and thus is no longer polarized. In addition, the beam shaping element may particularly include a hollow reflector or a collimator, which is particularly beneficial for beam shaping the light incident thereon (i.e., the pump light 2101 and / or the luminescent material light 201). In addition, in an embodiment, the optical element 580 may further include a diffuser, where the light incident on the diffuser may particularly undergo scattering, so as to provide diffused system light 1001. Thus, in this way, the optical element 580 can be used in particular to change the quality of the provided system light 1001.

[0139] In an embodiment, the luminescent body 210 may be configured such that (under the perpendicular radiation of the pump light 2101) the radiant flux within the range of 30% to 80% of the total radiant flux of the pump light 2101 can be absorbed by the luminescent body 210 during a single pass through the luminescent body 210. As described above, the luminescent body 210 can particularly absorb a part of the total radiant flux of the pump light 2101, and the degree of absorption can depend on the thickness of the luminescent body 210. That is, in an embodiment, a thicker luminescent body 210 can absorb a larger amount of the radiant flux in the total radiant flux of the pump light 2101. In addition, in an embodiment, the degree of absorption of the total radiant flux of the pump light 2101 can depend on the luminescent material 200 included in the luminescent body 210. In particular, the luminescent material 200 may include 3 B 5 O 12 :Ce type of luminescent material, where A includes one or more of Y, La, Gd, Tb, and Lu, and B includes one or more of Al, Ga, In, and Sc. In a specific embodiment, the luminescent body 210 can particularly convert light with a wavelength in the blue wavelength range. Thus, in an embodiment, the first light generation device 2100 can be particularly configured to generate pump light 2101 with a wavelength in the blue wavelength range.

[0140] Figure 2a depicts the functionality of an embodiment of the light generation system 1000, particularly regarding the configuration of the reflective polarizer 500. In Figure 2a (left), pump light 2101 including both a first polarization and a second polarization can be incident on the luminary 210. In particular, the first polarization and the second polarization can be selected from p-polarization 2101p and s-polarization 2101s. As previously described, in an embodiment, the luminary 210 can be (at least partially) transparent to the pump light 2101. Thus, in an embodiment, a portion of the pump light 2101 can be converted into luminescent material light 201, and another portion of the pump light 2101 can remain unconverted. As shown, the p-polarized pump light 2101p and the luminescent material light 201 are subsequently incident on the reflective polarizer 500. In an embodiment, the reflective polarizer 500 can be reflective for s-polarized light and transmissive for p-polarized light. Thus, the spectral power distribution of the system light 1001 can include the peak intensities of the p-polarized pump light 2101p and the luminescent material light 201, as shown in the spectral distribution in Figure 2a (right). Additionally, in an embodiment, the pump light 2101 can also include s-polarized pump light 2101s. In particular, the s-polarized pump light 2101s can be incident on the luminary 210, and a portion of the s-polarized pump light 2101s can be converted into luminescent material light 201, and a portion of the s-polarized pump light 2101s can remain unconverted. Furthermore, in an embodiment, due to light scattering within the luminary 210, the s-polarized pump light 2101s may undergo partial depolarization. The light coupled out from the luminary 210 can in particular be incident on the reflective polarizer 500 configured further downstream (of the luminary 210). As described above, in an embodiment, the reflective polarizer 500 can reflect s-polarized light. Thus, the s-polarized pump light 2101s can be reflected upstream (backward) towards the luminary 210. In an embodiment, the reflected s-polarized pump light 2101s can subsequently be converted into luminescent material light 201 and can be scattered along the direction of the reflective polarizer 500. Thus, in this way, the s-polarized pump light 2101s can be converted into luminescent material light 201. Additionally, in an embodiment, the portion of the pump light 2101 that does not include s-polarization can be (at least partially) transmitted through the reflective polarizer 500. Thus, in this case, the spectral power distribution may include the pump light 2101 with p-polarized pump light 2101p having zero intensity or minimum intensity (due to partial scattering and depolarization of the s-polarized pump light 2101s), and the spectral distribution may only show the peak intensity of the luminescent material light 201 (see Figure 2a (right)). In particular, the intensity of the luminescent material light 201 converted from the s-polarized pump light 2101s may be higher than the intensity of the luminescent material light 201 converted from the p-polarized pump light 2101p; this is because the s-polarized pump light 2101s may undergo multiple conversions (as described above).

[0141] Figure 2b depicts an embodiment of an optical generation device 2100 configured to generate pump light 2101. In particular, Embodiment I depicts an embodiment including two different light sources 10, which are also denoted herein by reference numerals 2110 and 2120, respectively, and are configured to generate p-polarized pump light 2101p and s-polarized pump light 2101s. Thus, the p-polarized pump light 2101p may include p-polarized source light 11p, while the s-polarized pump light 2101s may include s-polarized source light 11s. Thus, in this way, pump light 2101 of two different polarizations can be generated. This can also facilitate controlling the ratio of the pump lights 2101p and 2101s having corresponding different polarizations.

[0142] Alternatively, as shown in Embodiment II of Figure 2b, the first optical generation device 2100 may include (different) light sources 10 that may not provide the desired polarized light. These light sources are also denoted herein by reference numerals 2110 and 2120. In particular, the first pump light source 2110 may be optionally combined with a first optical device 591 and may be configured to generate pump light 2101 including a first polarization, i.e., p-polarized pump light 2101p. In addition, in the embodiment, the second pump light source 2120 may be optionally combined with a second optical device 592 and may be configured to generate pump light 2101 including a second polarization, i.e., s-polarized pump light 2101s. Thus, in this way, pump light 2101 of two different polarizations can be generated.

[0143] In addition, Embodiment III (as shown in Figure 2b) depicts a first optical generation device 2100 including a light source 10. In the embodiment, the light source 10 generates source light 11. In particular, the source light 11 may be incident on a third optical device 593, where the source light 11 may be polarized by the third optical device to provide pump light 2101. The third optical device 593 may control the polarization of the pump light 2101 to one or more of a first polarization and a second polarization.

[0144] FIG. 2c schematically shows an embodiment of a light generation system 1000 including a first reflector 530. In particular, the first reflector 530 may be disposed downstream of a first light generation device 2100 (not shown) and upstream of a light emitter 210. In particular, the first reflector 530 may be reflective for the luminescent material light 211 and transmissive for the pump light 2101. In an embodiment, the first reflector 530 may comprise a dichroic filter. The operation of such an embodiment is shown in two embodiments. In Embodiment I, the first reflector 530 may be transmissive for the pump light 2101. Thus, the pump light 2101 may in particular be transmitted through the first reflector 530 and incident on the light emitter 210. In an embodiment, a portion of the pump light 2101 may remain unconverted and be incident on a reflective polarizer 500 (which may be configured to be transmissive for a particular polarization angle, e.g., p-polarization or s-polarization). Thus, in an embodiment, the pump light 2101 may be coupled out. In an embodiment, a portion of the pump light 2101 incident on the light emitter 210 may be converted into luminescent material light 201, some of which may be transmitted (through the light emitter) and coupled out via the reflective polarizer 500, while a portion of the luminescent material light 201 may be reflected upstream onto the first reflector 530. In an embodiment, the luminescent material light 201 incident on the first reflector 530 may be reflected (back) downstream in the direction of the light emitter 210, and at least a portion of the luminescent material light 201 may be coupled out via the reflective polarizer 500. Thus, in such an embodiment, by using the first reflector 530 (which may be reflective for the luminescent material light 530), the coupled-out luminescent material light 201 may be increased. In this embodiment, the reflector 530 may be, for example, a dichroic filter that is transmissive for the pump light 2101 but reflective for the luminescent material light 201.

[0145] Alternatively, in Embodiment II, the first reflector 530 may (also) include a first pinhole 531. The first pinhole 531 in the embodiment may provide the advantage of not blocking the path of the pump light 2101. In an embodiment, the first light generation device 2100 may be configured to irradiate the light emitter 210 with the pump light 2101 via the first pinhole 531. Thus, in this way, the pump light 2101 may be incident on the light emitter 210 without interacting with other elements included in the light generation system 1000. Further, in an embodiment, the pump light 2101 may be partially converted into luminescent material light 201, and both the pump light 2101 and the luminescent material light 201 may be provided. Further, a portion of the luminescent material light 201 may be coupled out after subsequent reflection at the first reflector 530. The first reflector 530 may be a dichroic filter, but may in particular be a simple reflector, such as having a metal coating, e.g., an Al coating.

[0146] FIG. 2d schematically depicts an embodiment of a light generation system 1000, which further includes a second light generation device 2200. In particular, the second light generation device 2200 may be configured to generate a second device light 2201, whose spectral power distribution is different from that of the pump light 2101 and the luminescent material light 201. Thus, in this way, the spectral power distribution of the system light 1001 can be further controlled (or changed) in embodiments. In an embodiment, the second light generation device 2200 may include a second solid-state light source 20, which is selected from the group including superluminescent diodes and laser diodes. Additionally, in an embodiment, the control system 300 may be configured to control the spectral characteristics of the system light 1001 (as shown in embodiments I-V) by controlling the polarization of the pump light 2101 and by controlling the second light generation device 2200.

[0147] In an embodiment, the second device light 2201 may include spectral intensities in one or more ranges within the green wavelength range and the red wavelength range.

[0148] As previously described, the control system 300 may control the intensity of one or more light generation devices 2100, 2200. Thus, in this way, the control system 300 can change or control the spectral power distribution of the coupled-out system light 1001.

[0149] In embodiment I shown in FIG. 2d, the second light generation system 2200 is configured upstream of the luminaire 210. In an embodiment, the luminaire 210 may be transmissive to at least a portion of the second device light 2201. Additionally, in an embodiment, the reflective polarizer 500 may also be transmissive to at least a portion of the second device light 2201. Additionally, in an embodiment, the second device light 2201 may include polarized light having a first polarization. However, in other embodiments, the second device light 2201 may also include polarized light having a second polarization direction, as shown in embodiment I.

[0150] In Embodiment II shown in FIG. 2d, the second light generation device 2200 may be configured at a different spatial position from the first light emitting device 2100. In this way, in the embodiment, the pump light 2101 may (also) be directed in a direction different from the second device light 2201. In the illustrated embodiment, a partially transmissive optical element 550 (e.g., a dichroic mirror) may be configured upstream of the light emitter 210. In the embodiment, the optical element 550 may be transmissive to the pump light 2101. Thus, in this way, the pump light 2101 incident on the optical element 550 may pass through the optical element 550 and may be incident on the light emitter 210 (and subsequently on the reflective polarizer 500). In addition, in the embodiment, the second device light 2201 may also be incident on the optical element 550. However, in the embodiment, the optical element 550 may be reflective to the second device light 2201. In particular, the second device light 2201 may be reflected by the optical element 550 in the direction of the light emitter 210 (and subsequently the reflective polarizer 500).

[0151] Embodiment III shown in FIG. 2d may include features similar to those described in Embodiment II. For the sake of brevity, these features will not be described again. Embodiment III differs from Embodiment II in that the first reflector 530 may be configured upstream of the light emitter 210 and the reflective polarizer 500. In addition, in the embodiment, the first reflector 530 may include a pinhole 531. In particular, the pump light 2101 and the second device light 2201 may be incident on the light emitter 210 without contacting the first reflector 530. In such embodiments, the converted luminescent material light 201 may be reflected by the first reflector 530 in the downstream direction. Thus, in this way, the intensity of the luminescent material light 201 included in the system light 1001 can be increased.

[0152] Embodiment IV shown in FIG. 2d shows an embodiment including a first reflector 530 that further includes a first pinhole 531 and an additional second pinhole 532. In such an embodiment, the light generation system 1000 may include a first light generation device 2100 and a second light generation device 2200, where the pump light 2101 may be incident on the light emitter 210 via the first pinhole 531. In addition, in the embodiment, the second device light 2201 may be incident on the light emitter 210 via the second pinhole 532. Thus, in this way, both the pump light 2101 and the second device light 2201 can be incident on the light emitter 210 without contacting any other elements. In addition, the first reflector 530 may provide the advantage of reflecting the luminescent material light 201 and thus increasing the intensity of the luminescent material light 201 included in the system light 1001.

[0153] In Embodiment V shown in FIG. 2d, the second light generating device 2200 may be configured such that at least a portion of the second device light 2201 bypasses the light emitter 210 and the reflective polarizer 500. Thus, in this embodiment, the light generating device 2100 may generate pump light 2101, which may be incident on the light emitter 210 (and subsequently on the reflective polarizer 500). Further, in the embodiment, the optical element 550 may be configured further downstream of the reflective polarizer 500, where the reflective polarizer 500 may be transmissive for the pump light 2101. Thus, in this way, system light 1001 including the pump light 2101 may be provided in particular. Further, the light generating system 100 may further include a second light generating device 2200, which may provide the second device light 2201. In particular, the second device light 2201 may be incident on the optical element 550. In the embodiment, the optical element 550 may be reflective for the second device light 2201, and thus, the second device light 2201 may be reflected in the direction of the pump light 2101. Thus, system light 1001 including a combination of the pump light 2101, the second device light 2201, and the luminescent material light 201 may be provided. In particular, in the shown embodiment, the optical element 550 may be configured downstream of the reflective polarizer 500, and thus, the second device light 2201 may be arranged such that it may bypass the light emitter 210 and the reflective polarizer 500.

[0154] Figure 3 An embodiment of the lighting device 1200 is schematically depicted. In an embodiment, the lighting device 1200 may be selected from the group consisting of a lamp 1, a luminaire 2, a projector device 3, a disinfection device, a photoreactor, and an optical wireless communication device including the lighting system 1000 described herein. Reference numeral 301 denotes a user interface, which may be functionally coupled to a control system 300 included in or functionally coupled to the lighting system 1000. The figure also schematically depicts an embodiment of a lamp 1 including the lighting system 1000. Reference numeral 3 denotes a projector device or a projector system, which may be used to project an image onto a wall or the like, which may also include the lighting system 1000. In an embodiment, such a lighting device may be a lamp 1, a luminaire 2, a projector device 3, a disinfection device, or an optical wireless communication device. The lighting device light escaping from the lighting device 1200 is denoted by reference numeral 1201. The lighting device light 1201 may substantially consist of the system light 1001 and may thus be the system light 1001 in a particular embodiment. Reference numeral 1300 denotes a space, such as an office or a living room, where reference numeral 1307 corresponds to the wall of the living room and reference numeral 1305 corresponds to the floor.

[0155] The term "plurality" means two or more. Those skilled in the art can understand the terms "substantially" or "essentially" and similar terms used herein. The terms "substantially" or "essentially" may also include embodiments using "entirely", "completely", "all", etc. Thus, in embodiments, the adjectives "substantially" or "essentially" may also be omitted. Where applicable, "substantially" or "essentially" may also refer to 90% or higher, such as 95% or higher, especially 99% or higher, and even more especially 99.5% or higher, including 100%. The term "comprising" also includes embodiments in which "comprising" means "consisting of". The term "and / or" especially refers to one or more of the items mentioned before and after "and / or". For example, the phrase "item 1 and / or item 2" and similar phrases may refer to one or more of item 1 and item 2. The term "containing" may mean "consisting of" in one embodiment, but may also mean "containing at least the defined species and optionally one or more other species" in another embodiment. In addition, the terms "first", "second", "third", etc. in the specification and claims are used to distinguish similar elements and are not necessarily used to describe an order or a time sequence. It should be understood that, where appropriate, these terms may be interchanged, and the embodiments of the invention described herein may be operated in an order other than that described or shown herein. The use of the verb "comprising" and its inflected forms does not exclude the presence of elements or steps other than those recited in the claims. Unless the context clearly requires otherwise, throughout the specification and claims, the words "comprising", "comprises", etc. shall be construed in an inclusive sense, rather than an exclusive or exhaustive sense; that is, the meaning of "including but not limited to". The article "a" or "an" before an element does not exclude the presence of a plurality of such elements.

[0156] The devices, apparatuses or systems described herein may include situations during operation. Those skilled in the art should be clear that the present invention is not limited to the operation methods, or the devices, apparatuses or systems during operation.

[0157] It should be noted that the above embodiments are only for illustration and not for limiting the present invention. Those skilled in the art can design many alternative embodiments without departing from the scope of the appended claims. Any reference signs in parentheses in the claims shall not be construed as limiting the claims.

[0158] The present invention can be implemented by hardware including a plurality of different elements and a properly programmed computer. In apparatus claims, device claims or system claims listing a plurality of devices, a plurality of these devices can be implemented by the same hardware. The fact that certain measures are stated in mutually different dependent claims does not mean that a combination of these measures cannot be used to advantage. On the other hand, the present invention thus provides a software product which, when run on a computer, is capable of implementing one or more embodiments of the method described herein. The present invention also provides a control system which can control the apparatus, device or system, or can execute the method or process described herein. In addition, the present invention provides a computer program product which, when run on a computer functionally coupled to or included in the apparatus, device or system, can control one or more controllable elements of the apparatus, device or system. The present invention is also applicable to an apparatus, device or system comprising one or more features described in the specification and / or shown in the drawings. The present invention also relates to a method or process comprising one or more features described in the specification and / or shown in the drawings.

[0159] The various aspects discussed in this patent can be used in combination to provide further advantages. In addition, those skilled in the art should understand that embodiments can be combined and that more than two embodiments can also be used in combination. In addition, certain features can form the basis for one or more divisional applications.

Claims

1. A light generating system (1000), comprising a first light generating device (2100), a light emitter (210), a reflective polarizer (500) and a control system (300); in: The first light generating device (2100) is configured to generate a pump light (2101), the pump light having a controllable polarization, wherein the polarization is controllable between a first polarization and a second polarization; wherein the first light generating device (2100) comprises a first solid-state light source (10), the first solid-state light source being selected from the group consisting of a superluminescent diode and a laser diode; The light emitter (210) is arranged downstream of the first light generating device (2100), and during operation of the light generating system (1000), the pump light (1201) generated by the first light generating device (2100) is incident on the light emitter (210); The luminophore (210) comprises a luminescent material (200); wherein the luminophore (210) is configured to (a) transmit at least a portion of the pump light (2101), and (b) convert at least a portion of the pump light (2101) into luminescent material light (201); The reflective polarizer (500) is arranged downstream of the light emitter (210); wherein the reflective polarizer (500) is transmissive for at least a portion of the light emitting material light (201); wherein the reflective polarizer (500) has a higher transmittance for the pump light (2101) including the first polarization than for the pump light (2101) including the second polarization, wherein the reflective polarizer (500) has a lower reflectance for the pump light (2101) including the first polarization than for the pump light (2101) including the second polarization; The light generating system (1000) is configured to generate system light (1001); the system light is white light having a correlated color temperature in the range from 1800K to 10000K and a color rendering index of at least 70; The control system (300) is configured to control the spectral characteristics of the system light (1001) by controlling the polarization of the pump light (2101); In a first operating mode of the light generating system (1000), the system light includes a first radiant flux ratio X of the pump light (2101) and the luminescent material light (201). 1 / Y 1 , wherein in the second operation mode of the light generating system (1000), the system light includes a second radiant flux ratio X of the pump light (2101) and the luminescent material light (201) 2 / Y 2 , where X 1 / Y 1 >X 2 / Y 2 ;and The luminous body (210) is at least partially transparent to the pump light.

2. The light generating system (1000) according to claim 1, wherein the control system (300) is configured to: in an operating mode of the light generating system (1000), when a relative amount of a second radiation flux of the pump light (2101) including the second polarization is increased relative to a total radiation flux of the pump light (2101), reduce the total radiation flux of the pump light (2101).

3. The light generating system (1000) according to any one of the preceding claims, wherein X 1 / Y 1 ≥1.2*X 2 / Y 2 ; and wherein the luminescent body (210) is transparent.

4. A light generating system (1000) according to any one of the preceding claims, wherein the light emitting body (210) comprises a ceramic body or a single crystal; wherein the first polarization and the second polarization are selected from s-polarization and p-polarization; wherein the first solid-state light source (10) comprises a laser diode; wherein the control system (300) is configured to, in an operating mode of the light generating system (1000), control (a) a relative amount of a first radiant flux of the pump light (2101) comprising the first polarization relative to a total radiant flux of the pump light (2101); , and (b) controlling the correlated color temperature of the system light (1001) by a relative amount of the second radiant flux of the pump light (2101) including the second polarization relative to the total radiant flux of the pump light (2101) as defined in claim 2; wherein the light generating system (1000) further includes a downstream optical element (580), the downstream optical element (580) including one or more of a depolarizer, a beam shaping element and a diffuser, wherein the downstream optical element (580) is arranged downstream of the reflective polarizer (500).

5. A light generating system (1000) according to any of the preceding claims, wherein the light-emitting body (210) is configured so that a radiant flux in the range of 30% to 80% of the total radiant flux of the pump light (2101) is absorbed by the light-emitting body (210) in a single pass through the light-emitting body (210).

6. The light generating system (1000) according to any one of the preceding claims, wherein the luminescent material (200) comprises A 3 B 5 O 12 : Ce type luminescent material, wherein A includes one or more of Y, La, Gd, Tb and Lu, and wherein B includes one or more of Al, Ga, In and Sc; and wherein the first light generating device (2100) is configured to generate pump light (2101) having a wavelength within the blue wavelength range.

7. A light generating system (1000) according to any of the preceding claims, wherein the first light generating device (2100) comprises (a) a first pump light source (2110) and (b) a second pump light source (2120); wherein the first pump light source (2110) is optionally configured in combination with a first optical device (591) to generate the pump light (2101) comprising the first polarization, and wherein the second pump light source (2120) is optionally configured in combination with a second optical device (592) to generate the pump light (2101) comprising the second polarization.

8. The light generating system (1000) according to any of the preceding claims, further comprising a first reflector (530), which is arranged downstream of the first light generating device (2100) and upstream of the light emitting body (210), wherein the first reflector (530) is reflective with respect to the light emitting material light (211) and is transmissive with respect to the pump light (2101).

9. The light generating system (1000) according to claim 8, wherein the first reflector (530) comprises a first pinhole (531), wherein the first light generating device (2100) is configured to illuminate the light emitter (210) with the pump light (2101) via the first pinhole (531).

10. The light generating system (1000) according to any one of the preceding claims, further comprising a second light generating device (2200), the second light generating device being configured to generate a second device light (2201), the second device light having a spectral power distribution different from the pump light (2101) and different from the luminescent material light (201); wherein the second light generating device (2200) comprises a second solid-state light source (20), the second solid-state light source (20) being selected from a group comprising a superluminescent diode and a laser diode; wherein the control system (300) is configured to control the spectral characteristics of the system light (1001) by controlling the polarization of the pump light (2101) and by controlling the second light generating device (2200).

11. The light generating system (1000) according to claim 10, wherein the second light generating device (2200) is configured to allow at least a portion of the second device light (2201) of the second light generating device to bypass the light emitter (210) and the reflective polarizer (500).

12. The light generating system (1000) of claim 10, wherein the second light generating device (2200) is arranged upstream of the light emitter (210), wherein the light emitter (210) is transmissive to at least a portion of the second device light (2201), and wherein the reflective polarizer (500) is transmissive to at least a portion of the second device light (2201).

13. The light generating system (1000) of claim 12, wherein the second device light (2201) comprises polarized light having the first polarization.

14. The light generating system (1000) of any of the preceding claims 10-13, wherein the second device light (2201) comprises a spectral intensity within one or more of a green wavelength range and a red wavelength range.

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

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