High intensity light source with high cri

Abstract

The invention provides a light generating device (1000), wherein: (I) the light generating device (1000) comprises: (a) a first light source (110) configured to generate first light source light (111) having a first light source spectral power distribution, wherein the first light source (110) comprises a first laser light source (10) configured to generate first laser light source light (11); (b) a first luminescent material (210) configured to convert at least part of the first light source light (111) into first luminescent material light (211) having a first luminescent material spectral power distribution having emission at one or more wavelengths selected from the wavelength range of 590-780 nm, wherein the first luminescent material (210) is configured in an optical resonator (230); (II) the first light source (110) and the first luminescent material (210) are configured to generate first luminescent material laser light (1211) having a first luminescent material laser spectral power distribution comprising at least part of the first luminescent material light (211); (III) the first light source spectral power distribution and the first luminescent material laser spectral power distribution are mutually different; and (IV) the light generating device (1000) is configured to generate, in one or more operational modes, white device light (1001) comprising the first luminescent material laser light (1211).

Description

TECHNICAL FIELD

[0001] The present invention relates to a light generating device and a luminaire or lamp comprising such a light generating device. BACKGROUND

[0002] White light sources using laser diodes and phosphors are known in the art. For example, US2018 / 0316160 describes an apparatus and method of an integrated white electromagnetic radiation source using a combination of a laser diode excitation source based on gallium and nitrogen containing materials and a luminescent source based on phosphor materials. A violet, blue or other wavelength laser diode source based on gallium and nitrogen materials can be tightly integrated with a phosphor material, such as a yellow phosphor, to form a compact, high brightness and high efficiency white light source. The phosphor material is provided with a plurality of scattering centers inscribed on the excitation surface or inside the plate to scatter electromagnetic radiation of the laser beam incident on the excitation surface from the excitation source to enhance the generation and quality of the light emitted from the phosphor material for outputting white light emission in a reflective mode or a transmissive mode.

[0003] US2003 / 035447A1 discloses a light generator that can generate light having selected proportions of red, green and blue wavelengths from a blue light source. The light generator comprises a blue laser for generating a first beam of blue light and a beam splitter for splitting the beam of blue light into separate beams, each beam generating light of a single color by using an up-conversion laser, thereby producing light having a single color. SUMMARY

[0004] Although white LED sources can give an intensity of 300 lm / mm 2 , static phosphor converted laser white sources can give an intensity of 20.000 lm / mm 2 . Ce doped garnets (YAG, LuAG) can be the most suitable luminescence converters, which can be used for pumping with blue lasers, as the garnet matrix has the highest chemical stability and temperature quenching occurs above 200°C at low Ce concentrations (below 0.5%). Furthermore, the emission from Ce has a very fast decay time, so that optical saturation can be avoided. In previous applications, such as automotive, a correlated color temperature above 5000 K at low CRI has been demonstrated. When it is required to produce a light source with an intensity higher than 1 GCd / m 2 at a CRI > 90 and a lower CCT < 3000 K, a red light source or a red emitting laser is required. However, some Eu 2+ based red emitting phosphors quench, degrade or show saturation at such high intensities. Red lasers can also show a different aging behavior than blue lasers and therefore the color point of the light source changes during its lifetime, which is not desirable.

[0005] It is thus an aspect of the present application to provide an alternative light generating device which preferably further at least partially obviates one or more of above-described drawbacks. It is an object of the present application to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.

[0006] Amongst others, it is suggested herein to use a rare earth doped crystal which can give down-converted laser emission in the red region when excited by a blue laser. A part of the blue laser can then be used to pump e.g. a cerium doped YAG phosphor. A combination of spontaneous emission light from YAG, stimulated emission from the red emitting crystal and blue emitting laser, white light with a CRI higher than 90 can be obtained at a CCT lower than 3500 K or even lower than 3000 K, substantially on the black body locus BBL. However, other embodiments are possible as well.

[0007] In a first aspect, the application provides a light generating device ("lighting device" or "device"), which is especially configured to generate device light ("light generating device light"). In particular, the light generating device comprises a first light source and a first luminescent material. The light generating device further comprises a second light source. The light generating device comprises (a) a first light source configured to generate first light source light having a first light source spectral power distribution. The first light source comprises a first laser light source configured to generate first laser light source light. Further, the light generating device comprises (b) a first luminescent material configured to convert at least part of the first light source light into first luminescent material light having a first luminescent material spectral power distribution. The first luminescent material light has an emission in one or more wavelengths selected from the wavelength range of 590-780 nm. In particular, the first luminescent material light has an emission of a dominant wavelength selected from the wavelength range of 590-780 nm, more in particular from the wavelength range of 618-630 nm. The first light source and the first luminescent material are configured to generate first luminescent material laser light having a first luminescent material laser spectral power distribution comprising at least part of the first luminescent material light. The first light source spectral power distribution and the first luminescent material laser spectral power distribution are mutually different. The light generating device is configured to generate, in one or more operational modes (of the light generating device), white device light comprising the first luminescent material laser light. The first luminescent material is configured in an optical resonator. Thus, the application provides a light generating device, wherein the light generating device comprises: (a) a first light source configured to generate first light source light having a first light source spectral power distribution, wherein the first light source comprises a first laser light source configured to generate first laser light source light; (b) a first luminescent material configured to convert at least part of the first light source light into first luminescent material light having a first luminescent material spectral power distribution having an emission in one or more wavelengths selected from the wavelength range of 590-780 nm, wherein the first luminescent material is configured in an optical resonator; and wherein (i) the first light source and the first luminescent material are configured to generate first luminescent material laser light having a first luminescent material laser spectral power distribution comprising at least part of the first luminescent material light; (ii) the first light source spectral power distribution and the first luminescent material laser spectral power distribution are mutually different; (iii) the light generating device is configured to generate, in one or more operational modes (of the light generating device), white device light comprising the first luminescent material laser light. Further, the light generating device (c) comprises a second light source configured to generate second light source light having a second light source spectral power distribution. The second light source comprises a second laser light source configured to generate second laser light source light.

[0008] With such a device, it is possible to provide high intensity white light with a relatively low correlated color temperature (CCT), such as below about 3000 K, and a relatively high color rendering index, such as at least 85, even about 90. Further, with such a device, it is even possible to use a single laser light source or a single type of laser light source, which can further reduce possible color changes of the device light over time. Thus, among others, the present invention provides a high intensity light generating device with substantially no color point shift related to differences in aging over time, using a rare earth doped crystal for stimulated emission of red, for obtaining high CRI and R9 at e.g. color temperatures below about 3000 K.

[0009] As indicated above, the light generating device comprises (i) a first light source configured to generate first light source light. The first light source light can have a wavelength in one or more of UV, blue, green and yellow. In particular, the first light source light has one or more blue wavelengths. Even more in particular, the first light source light has a dominant wavelength in blue. Thus, in embodiments, the light generating device comprises (i) a first light source configured to generate blue first light source light. Thus, the first light source light can in particular have a color point of blue.

[0010] The first light source comprises a first laser light source. The first laser light source is configured for generating first laser light source light. In embodiments, the first light source light can substantially consist of the first laser light source light. Thus, in embodiments, the first light source is the first laser light source. In embodiments, the term "first light source" can also refer to a plurality of identical first light sources. In embodiments, a group of first laser light sources can be applied. Alternatively or additionally, the term "first light source" can also refer to a plurality of different first light sources. In embodiments, the term "first laser light source" can also refer to a plurality of identical first laser light sources. Alternatively or additionally, the term "first laser light source" can also refer to a plurality of different first laser light sources.

[0011] Still further, the light generating device comprises a first luminescent material configured to convert a part of the first light source light into first luminescent material light having a first luminescent material spectral power distribution. In particular, this first luminescent material light has one or more of the (emission) wavelengths in the orange and / or red. The first luminescent material light has emission at one or more wavelengths selected from the wavelength range of 590-780 nm. Even more in particular, such as in view of the CRI, the first luminescent material light can have emission at one or more wavelengths selected from the wavelength range of 605-780 nm, even more in particular 605-645 nm. Yet even more in particular, the first luminescent material light can have (at least) emission at one or more wavelengths selected from the wavelength range of 605-650 nm, such as from the range of 618-645 nm, even more in particular in the range of 618-632 nm. In a particular embodiment, the first luminescent material light can have emission at a dominant wavelength selected from the wavelength range of 605-650 nm, such as from the range of 618-645 nm, even more in particular in the range of 618-632 nm. It appears that for such dominant wavelengths, a high CRI can be provided in a relatively effective manner.

[0012] The term "luminescent material" especially refers to a material which can convert a first radiation, especially one or more of UV radiation and blue radiation, into a second radiation. Typically, the first and second radiation have different spectral power distributions. Hence, instead of the term "luminescent material", also the term "luminescence converter" or "converter" can be applied. Typically, the second radiation has a spectral power distribution at a larger wavelength than the first radiation, which is the case in so-called down-conversion. However, in a particular embodiment, the second radiation has a spectral power distribution of intensity at a smaller wavelength than the first radiation, which is the case in so-called up-conversion. In embodiments, "luminescent material" can especially refer to a material which can convert radiation into e.g. visible and / or infrared light. For example, in embodiments, the luminescent material is capable of converting one or more of UV radiation and blue radiation into visible light. In a particular embodiment, the luminescent material can also convert radiation into infrared radiation (IR). Hence, upon excitation with radiation, the luminescent material emits radiation. Typically, the luminescent material will be a down-converter, i.e. radiation of a smaller wavelength is converted into radiation having a larger wavelength (λ ex <λ em ) although in a particular embodiment, the luminescent material can comprise a down-converter luminescent material, i.e. radiation of a larger wavelength is converted into radiation having a smaller wavelength (λ ex >λ em) of the first luminescent material. In some embodiments, the term "luminescence" can refer to phosphorescence. In embodiments, the term "luminescence" can also refer to fluorescence. Instead of the term "luminescence", the term "emission" can also be applied. Thus, the terms "first radiation" and "second radiation" can refer to excitation radiation and emission (radiation), respectively. Similarly, the term "luminescent material" can in embodiments refer to phosphorescence and / or fluorescence. The term "luminescent material" can also refer to a plurality of different luminescent materials.

[0013] The first luminescent material is used to generate a laser light having a laser emission in orange and / or red, in particular at least in red. Thus, in particular, the first luminescent material can be used to generate a laser light having a laser emission with one or more wavelengths selected from the wavelength range of 610-650 nm, such as 618-650 nm, like from the range of 618-645 nm. Thus, in embodiments, the first light source and the first luminescent material and optional first optics are configured to generate a first luminescent material laser light having a peak wavelength in the wavelength range of 618-650 nm, such as in the range of 618-632 nm.

[0014] Optionally, (first) optics can be applied to filter out undesired (emission) wavelengths. However, this can also result in a reduction of efficiency.

[0015] Thus, in embodiments, the first light source and the first luminescent material are configured to generate a first luminescent material laser light having a first luminescent material laser spectral power distribution comprising at least a portion of the first luminescent material light. By pumping the first luminescent material with a laser and, for example, configuring the luminescent material between two (wavelength dependent) mirrors, the first luminescent material can be brought into a lasing mode. Laser technology comprising solid state luminescent materials are known in the art (such as Cr 3+ , Ti 3+ , etc.).

[0016] In particular, in embodiments, the luminescent material comprises a luminescent ceramic body or a luminescent crystal.

[0017] In order to obtain a red laser light, in particular some trivalent lanthanides can be applied. Thus, in particular embodiments, the first luminescent material can comprise an inorganic material doped with a rare earth ion, in particular a trivalent rare earth ion. In particular, the (trivalent) rare earth ion is selected to convert one or more of blue light and UV radiation into visible light, in particular red light.

[0018] In particular, trivalent praseodymium seems useful herein. Thus, in embodiments, the first luminescent material comprises Pr 3+ , for example, 3 one of the P states (and / or 1 I6 states) can be pumped (as3 P2 state), which can lead to 3 F 2 state. However, other transitions are possible.

[0019] In particular embodiments, the first luminescent material can comprise Pr 3+ doped aluminate. For example, in embodiments, the first luminescent material can comprise strontium lanthanum magnesium aluminate. In particular, in embodiments, the first luminescent material can comprise Sr 1-x- y La x Pr y Mg x+y Al 12-x-y O 19 wherein 0 < x < 1, 0 < y < 1, and 0 < x + y < 1. In particular, 0.0001 < y < 0.1, such as 0.001 < y < 0.03, like about 0.001 < y < 0.02. In embodiments, 0 < x < 1. Even more in particular, in embodiments, the first luminescent material can comprise Sr 0.7 La 0.3 Mg 0.3 Al 11.7 O 19 : Pr 3+ with about 0.05-5, such as 0.05-3 at. % of Pr 3+ , such as about 0.1 -2 at. %, such as for example described by S. Sattayaporn et al. in Optics Express, vol. 26(2), 22 January 2018, pages 1278-1289. Alternatively, embodiments of the first luminescent material can comprise YLF (LiYF4: Pr 3+ ) or YAP (YAlO3 (or yttrium aluminum perovskite)), or YAG (Y3Al5O 12 : Pr 3+ ), such as described by M. Malinowski et al. in Journal de Physique IV, Collogue C4 supplement au Journal de Physique III, vol. 4, April 1994, pages C4-541 -544 (https: / / hal. archives-ouvertes.fr / file / index / docid / 252582 / filen ame / aip-ip4199404C4130.pdf). However, other materials than the above can also be used.

[0020] Using a laser as pump source, the laser radiation, such as a blue emitting laser diode (LD), can be collimated by a collimator, which is typically a high precision aspheric lens with a short focal length and a high numerical aperture. The resulting beam can be parallel in one axis, showing a roughly rectangular to elliptical intensity cross section.

[0021] A focusing lens can be used to focus the blue pump laser radiation into a Pr-doped host lattice, such as YLF, YAP or one of the above mentioned aluminates. The Pr-doped host lattice can be coated with a broadband anti-reflective coating (so-called ARB coating) on both sides only. The lowest reflective wavelength range covers the entire emission range of the Pr-doped material including the pump radiation, such as in embodiments around 445 nm (YLF). In embodiments, the optical cavity can be formed by a flat mirror on one side and a curved mirror (M2) on the other side, with the Pr-doped host lattice in between. In principle, it is also possible to coat a laser mirror directly onto one side of the Pr-doped host lattice. However, this can reduce the flexibility to operate at different wavelengths, as an additional laser crystal is needed for each specific wavelength.

[0022] Herein, "Pr-doped host lattice" refers to a ceramic or a crystal of a Pr-doped material. In particular, a crystal can be applied.

[0023] The skilled person knows how to construct a solid state laser. Among others, a laser cavity can be applied. These can also be denoted as "optical cavity" or "resonator". In a resonator, the laser light is amplified in a gain medium. A laser resonator can typically be formed by using high reflective dielectric mirrors or monolithic crystals that prevent light from escaping by total internal reflection. For example, a plane-parallel resonator can be used, which comprises two plane mirrors separated by a distance equal to an integer number of half the laser wavelength. A concentric resonator can also be used, which comprises two spherical mirrors with the same radius of curvature and coinciding centers of curvature. A confocal resonator can also be used, which comprises two spherical mirrors with the same radius of curvature and coinciding focal points. Further, a ring resonator can be used, in which a ring of more than two reflectors is applied, in which the total closed loop path of the reflected light is equal to an integer number of half the laser wavelength. Thus, a solid state body laser is typically constructed with several dielectric mirrors (laser mirrors), which can be flat or curved. A luminescent ceramic body luminescent crystal is used as gain medium. In some embodiments, the dielectric mirror coating is placed on the gain medium itself. One of the mirrors, typically the end mirror, is partially transmissive as an output coupler.

[0024] The first luminescent material is configured in an optical resonator (or "laser cavity"). In particular, the optical resonator can be defined by two (wavelength dependent) mirrors (and the luminescent body). However, a ring resonator can also be applied (see also above).

[0025] As mentioned above, for example, a Pr-doped material can be pumped with blue light. Therefore, in embodiments, the first light source is configured to generate blue first light source light. In particular, in embodiments, the first light source is configured to generate blue laser light.

[0026] As further elucidated below, it can be desirable to generate white light in one or more operational modes. Red (laser based on a luminescent material) light alone cannot produce white light. Therefore, one or more other light sources can be applied. For white light, typically a combination of blue light with one or more of yellow and orange light, or a combination of blue light with red light and one or more of yellow and green light is required.

[0027] In embodiments, substantially all of the first light source light can be used to irradiate the first luminescent material, but not all of the first light source light can be converted by the first luminescent material into first luminescent material laser light. At least a part of the unconverted first light source light can be used to provide at least a part of one of the above-mentioned light components. At least a part of the first luminescent material laser light can be used to provide at least a part of another one of the above-mentioned light components. For example, the first light source light can be blue light, and the first luminescent material laser light can comprise one or more of orange and red light.

[0028] Alternatively or additionally, a part of the first light source can be used to generate first luminescent material laser light, and a part of the first light source light can bypass the first luminescent material. At least a part of the unconverted first light source light can be used to provide at least a part of one of the above-mentioned light components. At least a part of the first luminescent material laser light can be used to provide at least a part of another one of the above-mentioned light components. For example, the first light source light can be blue light, and the first luminescent material laser light can comprise one or more of orange and red light.

[0029] When a part of the light source light should bypass the luminescent material, a second optical device (e.g. a beam splitter) can be applied. The beam splitter can be a two-triangle based cube beam splitter. The beam splitter can be a polarizing beam splitter. The beam splitter can be a half-silvered mirror. Beam splitters are known in the art. For example, a depolarizing element can be used, or a combination of lasers with different polarization can be used. The light source can also emit different wavelength ranges (e.g. different types of blue). Therefore, in embodiments, a dichroic beam splitter can be used.

[0030] The part of the first light source light that can bypass the first luminescent material can be generated in several ways. In embodiments, the part can be branched off from the first light source. Hence, in such embodiments, the same first light source(s) generate the first light source light that is branched in the first light source light for illuminating the first luminescent material and that is branched in the first light source light that bypasses the first luminescent material. In other embodiments, two sets (or more sets) of first light sources can be used, wherein one set of one or more first light sources is used for illuminating the first luminescent material, while another set of one or more first light sources is used for generating the first light source light that bypasses the first luminescent material. The latter embodiment allows for separate control (and hence better spectral characteristic control) of the different sets.

[0031] In the above embodiments, the first light source light can be blue light, and the first luminescent material light can comprise one or more of orange light and red light. For white light, one or more of yellow light and green light are also included. Hence, in embodiments an additional light source can be needed. One or more of the yellow light and the green light can be generated in different ways.

[0032] In embodiments, one or more of the yellow light and the green light can at least partly be provided by luminescent material light. Hence, for this, the light generating device can comprise a further luminescent material, also denoted herein as second luminescent material. The second luminescent material can be configured to generate second luminescent material light comprising one or more of yellow light and green light.

[0033] Optionally, one or more of the yellow light and the green light can also be generated as second luminescent material light. This can be done according to similar principles as described with respect to the first luminescent material light. Note that the term “second luminescent material” can also refer to a plurality of different second luminescent materials (see also above). The second luminescent material can be pumped via the first light source or via a second light source (or in specific embodiments via both).

[0034] When using the first light source (to pump the second luminescent material), unconverted first light source light and / or first light source light that has bypassed the first luminescent material can be used to generate at least part of the second luminescent material light. Hence, note that using a single laser or a single type of laser, all light needed for white light can be generated. As described above, using the first light source light as pump light, one or more of the yellow light and the green light can be generated as second luminescent material light.

[0035] A second light source is used to pump the second luminescent material. Such second light source is in particular configured to generate second light source light having another spectral power distribution than the first light source light. The second light source comprises a second laser light source. As described above, using the second light source light as pump light, one or more of the yellow light and the green light can be generated as second luminescent material light.

[0036] The second light source comprises a second laser light source. The second laser light source is configured for generating second laser light source light. The second light source comprises a second laser light source. Hence, in embodiments, the second light source is a second laser light source. In embodiments, the term "second light source" can also refer to a plurality of identical second light sources. In embodiments, a group of second laser light sources can be applied. Alternatively or additionally, the term "second light source" can also refer to a plurality of different second light sources. In embodiments, the term "second laser light source" can also refer to a plurality of identical second laser light sources. Alternatively or additionally, the term "second laser light source" can also refer to a plurality of different second laser light sources.

[0037] Hereinafter, some embodiments are discussed.

[0038] The first light source and the second light source can be chosen individually and hence are not necessarily of the same type (although the first light source and the second light source are different in definition as the light source light generated by the first light source is different in spectral power distribution from the second light source light).

[0039] In this document, the term "violet light" or "violet emission" relates especially to light having a wavelength in the range of about 380-440 nm. The term "blue light" or "blue emission" relates especially to light having a wavelength in the range of about 440-495 nm (including some violet and cyan hues). The term "green light" or "green emission" relates especially to light having a wavelength in the range of about 495-570 nm. The term "yellow light" or "yellow emission" relates especially to light having a wavelength in the range of about 570-590 nm. The term "orange light" or "orange emission" relates especially to light having a wavelength in the range of about 590-620 nm. The term "red light" or "red emission" relates especially to light having a wavelength in the range of about 620-780 nm. The term "pink light" or "pink emission" refers to light having a blue and a red component.

[0040] The terms "light" and "radiation" are used interchangeably herein unless it is clear from the context that the term "light" refers only to visible light. Hence, the terms "light" and "radiation" can refer to UV radiation, visible light and IR radiation. In particular embodiments, especially for lighting applications, the terms "light" and "radiation" refer to visible light.

[0041] The term UV radiation can refer in particular embodiments to near UV radiation (NUV). Hence, the term "(N)UV" is used in this document as well, generally referring to UV, in particular embodiments to NUV. The term IR radiation can refer in particular embodiments to near IR radiation (NIR). Hence, the term "(N)IR" is used in this document as well, generally referring to IR, in particular embodiments to NIR.

[0042] In this document, the term "visible light" relates inter alia to light having a wavelength selected from the range of 380-780 nm.

[0043] The term "white light" herein is known to the person skilled in the art. It relates inter alia to light having a correlated color temperature (CCT) between about 1800 K and 20000 K, such as between 2000 K and 20000 K, especially between 2700 K and 20000 K, for general lighting especially in the range of about 2700 K and 6500 K. In embodiments, for backlighting purposes, the correlated color temperature (CCT) can in particular be in the range of about 7000 K and 20000 K. Further, in embodiments, the correlated color temperature (CCT) is especially within about 15 SDCM (standard deviation of color matching) from the BBL (black body locus), especially within about 10 SDCM from the BBL, even more especially within about 5 SDCM from the BBL.

[0044] The term“light source” can refer to a semiconductor light emitting device such as a light emitting diode (LED), a resonant cavity light emitting diode (RCLED), a vertical cavity laser diode (VCSEL), an edge emitting laser, or the like. The term“light source” can also refer to an organic light emitting diode such as a passive-matrix (PMOLED) or active-matrix (AMOLED). In particular embodiments, the light source comprises a solid state light source such as an LED or a laser diode. In embodiments, the light source comprises an LED (light emitting diode). The term LED can also refer to a plurality of LEDs. Further, the term“light source” can also refer to a so-called chip-on-board (COB) light source in embodiments. The term“COB” especially refers to an LED chip in the form of a semiconductor chip which is neither encapsulated nor connected but directly mounted onto a substrate such as a PCB. Thus, a plurality of semiconductor light sources can be configured on the same substrate. In embodiments, a COB is a plurality of LED chips configured together as a single lighting module. The term“light source” can also relate to a plurality of (essentially identical (or different)) light sources such as 2-2000 solid state light sources. In embodiments, the light source can comprise one or more micro-optical elements (microlens arrays) downstream of a single solid state light source such as an LED or of a plurality of solid state light sources (i.e. shared by a plurality of LEDs). In embodiments, the light source can comprise an LED with on-chip optics. In embodiments, the light source comprises a pixelated single LED (with or without optics) (providing on-chip beam steering in embodiments). The term“laser light source” especially refers to a laser. Such a laser can especially be configured to generate light having one or more of UV, visible light, or infrared, in particular a laser light source light having a wavelength selected from 200-2000 nm (such as 300-1500 nm). The term“laser” especially refers to a device that emits light through a process of optical amplification based on the principle of stimulated emission of electromagnetic radiation. In particular, the term“laser” can refer to a solid state laser in embodiments.

[0045] In embodiments, the term“laser” or“solid state laser” can refer to one or more of a cerium-doped lithium strontium (or calcium) aluminum fluoride (Ce:LiSAF, Ce:LiCAF). A chromium-doped gallium beryllium (alexandrite) laser, a chromium ZnSe (Cr:ZnSe) laser, a divalent samarium-doped calcium fluoride (Sm:CaF2) laser, an Er:YAG laser, an erbium-doped and erbium-ytterbium co-doped glass laser, an F-center laser, a holmium YAG (Ho:YAG) laser, a Nd:YAG laser, a NdCrYAG laser, a neodymium-doped yttrium calcium borate Nd:YCa4O(BO3)3 or Nd:YCOB, a neodymium-doped yttrium orthovanadate (Nd:YVO4) laser, a neodymium glass (Nd:glass) laser, a neodymium YLF (Nd:YLF) solid state laser, a praseodymium 147-doped phosphate glass (147Pm 3+: glass) solid-state lasers, ruby lasers (AI2O3:Cr 3+ ), thulium YAG (Tm:YAG) lasers, titanium sapphire (Ti: sapphire; AI2O3:Ti 3+ ) lasers, trivalent uranium-doped calcium fluoride (U:CaF2) solid-state lasers, ytterbium-doped glass lasers (rod, slab / chip and fiber), ytterbium YAG (Yb:YAG) lasers, Yb2O3(glass or ceramic) lasers. In embodiments, the term "laser" or "solid-state laser" can refer to one or more semiconductor laser diodes, such as GaN, InGaN, AlGalnP, AlGaAs, InGaAsP, lead salts, vertical cavity surface emitting lasers (VCSELs), quantum cascade lasers, hybrid silicon lasers, etc.

[0046] It can be derived from the below that the term "laser light source" can also refer to a plurality of (different or identical) laser light sources. In particular embodiments, the term "laser light source" can refer to a plurality of N (identical) laser light sources. In embodiments, N = 2 or more. In particular embodiments, N can be at least 5 (such as at least 8, in particular). In this way, a higher brightness can be obtained. In embodiments, the laser light sources can be arranged in a laser group. In embodiments, the laser group can comprise heat sinks and / or optics (e.g. lenses) to collimate the lasers. For example, a group can comprise at least 10 laser light sources.

[0047] The laser light source is configured to generate laser light source light (or "laser light"). The light source light can essentially consist of laser source light. The light source light can also comprise laser light source light of two or more (different or identical) laser light sources. For example, laser light source light of two or more (different or identical) laser light sources can be coupled into a light guide to provide a single beam of light comprising laser light source light of two or more (different or identical) laser light sources.

[0048] In particular embodiments, the light source light is thus in particular collimated light source light. In yet another embodiment, the light source light is in particular (collimated) laser light source light.

[0049] The phrase "different light sources" or "a plurality of different light sources" and similar phrases can in embodiments refer to a plurality of solid state light sources selected from at least two different bins. Similarly, the phrase "identical light sources" or "a plurality of identical light sources" and similar phrases can in embodiments refer to a plurality of solid state light sources selected from the same bin.

[0050] The light source is especially configured to generate light source light having an optical axis (O) (beam shape) and a spectral power distribution. In embodiments, the light source light can comprise one or more bands having a bandwidth known from lasers. In particular embodiments, the band(s) can be relatively sharp line(s), such as having a full width at half maximum (FWHM) in the range of less than 20 nm at RT, such as equal to or less than 10 nm. Hence, the light source light has a spectral power distribution (intensity on an energy scale as a function of wavelength) which can comprise one or more (narrow) bands.

[0051] In embodiments, the light source beam can be relatively highly collimated, such as < 2° (FWHM) in embodiments, more particularly < 1° (FWHM), most particularly < 0.5° (FWHM). Hence, < 2° (FWHM) can be considered as (highly) collimated light source light. Downstream of the laser, one or more optical elements can be configured to provide a collimated beam. For example, in embodiments, one or more lenses, especially at least two lenses, can be configured.

[0052] In particular, the first light source and the optional second light source are diode lasers.

[0053] As indicated above, the first light source can especially be configured to generate blue first light source light. Even more particularly, the first light source can especially be configured to generate first (laser) light source light which can be absorbed by trivalent lanthanide ions, such as in particular Pr 3+ resulting in one or more (laser) transitions in the orange and / or red.

[0054] For example, in embodiments, the light generating device can comprise one or more first light sources configured to generate first light source light, wherein: (a) the one or more first light sources, the first luminescent material and the optional second optics are configured to generate a part of the first light source light which bypasses the first luminescent material, and (b) in one or more operational modes of the light generating device, the light generating device can be configured to generate white device light comprising the first light source light which bypasses the first luminescent material, the first luminescent material laser light and the optional second light source light. When more than one first light source is applied, one or more of the first light sources can be used to irradiate the first luminescent material, and one or more other first light sources can be used to provide (blue) first light source light which bypasses the first luminescent material and which can be used as such (as a blue component) and / or which can for example be used to irradiate a second luminescent material (see also below). However, when a single first light source is applied, but also when more than a single first light source is applied, the second optics can be used to divert a part of the first light source light to bypass the first luminescent material (and which can be used as such (as a blue component) and / or which can for example be used to irradiate a second luminescent material (see also below)).

[0055] In yet another embodiment, the light generating device can further comprise a second light source configured to generate second light source light having a second light source spectral power distribution, wherein the second light source comprises a second laser light source configured to generate second laser light source light. In particular, the first light source spectral power distribution, the second light source spectral power distribution, and the first luminescent material laser spectral power distribution are mutually different. Further, in particular, in embodiments, the second light source can be configured to generate second light source light having a second light source spectral power distribution having one or more wavelengths in the green and yellow wavelength range. Hence, the light generating device can be configured to generate, in one or more operational modes (of the light generating device), white device light comprising (i) the first luminescent material laser light and (ii) the second light source light.

[0056] The light generating device further comprises a second luminescent material configured to convert at least part of the second laser light source light to provide second luminescent material light. The light generating device is configured to generate, in one or more operational modes (of the light generating device), white device light comprising the first luminescent material laser light and the second luminescent material light. The paths in which (white) device light light can be generated are discussed above (and also below).

[0057] In particular embodiments, (i) the first laser light source and the first luminescent material are configured to generate the first luminescent material laser light, (ii) the first laser light source and the second luminescent material are configured to generate the second luminescent material light, and (iii) the light generating device can be configured to generate, in one or more operational modes (of the light generating device), white device light comprising the first laser light source light, the first luminescent material laser light, and the second luminescent material light. As mentioned above, the first laser light source light can be e.g. blue light, the first luminescent material laser light can be red light, and the second luminescent material light can be one or more of yellow and green light.

[0058] In other embodiments, the light generating device can comprise a plurality of first laser light sources configured to generate blue laser light, wherein: (i) a first group of one or more first laser light sources is configured to generate blue first laser light that bypasses the first luminescent material and the second luminescent material, (ii) a second group of one or more first laser light sources is configured to generate blue first laser light that illuminates the first luminescent material but bypasses the second luminescent material, (iii) a third group of a plurality of first laser light sources is configured to generate blue first laser light that bypasses the first luminescent material but illuminates the second luminescent material, and in particular embodiments (iv) the light generating device can further comprise a control system configured to control the plurality of first laser light sources. Hence, in particular embodiments, even a single type of light source can be used in combination with luminescent materials to generate white device light, wherein at least part of the device light comprises laser light.

[0059] The light generating device comprises a second luminescent material. A particularly suitable (second) luminescent material is a cerium containing garnet material. Embodiments of the garnet include A3B5O 12 A garnet, wherein A comprises at least yttrium or lutetium, and wherein B comprises at least aluminum. Such a garnet can be doped with cerium (Ce), praseodymium (Pr) or a combination of cerium and praseodymium; however, it is particularly doped with Ce. In particular, B comprises aluminum (Al), however, B can also partially comprise gallium (Ga) and / or scandium (Sc) and / or indium (In), in particular up to about 20% of Al, more in particular up to about 10% of Al (i.e. the B ions essentially consist of 90% or more % by mole of Al and 10% or less % by mole of one or more of Ga, Sc and In); B can in particular comprise up to about 10% of gallium. In another variant, B and O can be at least partially replaced by Si and N. The element A can in particular be selected from the group consisting of yttrium (Y), gadolinium (Gd), terbium (Tb) and lutetium (Lu). Further, Gd and / or Tb are in particular present in an amount of A of up to about 20% only. In a particular embodiment, the garnet luminescent material comprises (Y 1-x Lu x )3B5O 12 :Ce, wherein x is equal to or larger than 0 and equal to or smaller than 1. The term ":Ce" indicates 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 the case of (Y 1-x Lu x )3Al5O 12 :Ce, a part of the Y and / or Lu is replaced by Ce. This is known to the person skilled in the art. Ce will replace A typically not more than 10%; typically, the Ce concentration will be in the range of 0.1-4%, in particular 0.1-2% (relative to A). Assuming 1% Ce and 10% Y, a fully correct molecular formula can be (Y 0.1 Lu 0.89 Ce 0.01 )3Al5O 12 . As is known to the person skilled in the art, Ce in the garnet is essentially or only in the trivalent state. In a particular embodiment, the luminescent material comprises (Y x1-x2-x3 A x2 Ce x3 )3(Al y1-y2 B y2 )5O 12where xl+x2+x3=l, where x3>0, where 0 x1-x2-x3 (Lu, Gd) x2 Ce x3 )3(Al y1-y2 Ga y2 )5O 12 where xl+x3=l, and where 0 x1-x3 Ce x3 )3Al5O 12 where xl+x3=l, and where 0 x1-x2-x3 A x2 Ce x3 )3(A1 y1-y2 B y2 )5O 12 .

[0060] The second luminescent material light can for example have a dominant wavelength in the orange-red wavelength range. Examples of such second luminescent material can for example be M2Si5N8:Eu 2+ and / or MAlSiN3:Eu 2+ and / or Ca2AlSi3O2N5:Eu 2+ etc., where M comprises one or more of Ba, Sr and Ca, in particular at least Sr in embodiments.

[0061] In embodiments, the first luminescent material can be provided by or comprise a single crystal or ceramic luminescent body. Hence, in embodiments, the luminescent body can comprise the first luminescent material.

[0062] Instead of the term "luminescent body" and similar terms, also the term "translucent body" and similar terms can be applied, as the luminescent body is also transmissive for the first luminescent material light.

[0063] As mentioned above, the light generating system comprises, among others, a luminescent body. The luminescent body can comprise (N) side(s) (over at least a part of the length L), with N > 3. Hence, in particular, the luminescent body has a square (N = 4), rectangular (N = 4), hexagonal (N = 6) or octagonal (N = 8) cross-sectional shape, in particular a rectangular cross-sectional shape. If the luminescent body has a circular cross-section, N can be considered to be ∞.

[0064] The (elongated) body comprises a first end or first face, which is generally configured perpendicular to one or more of the side(s); and a second end or second face, which can be configured perpendicular to one or more of the side(s) and hence parallel to the first face, but which can also be configured at an angle not equal to 90° and not equal to 180°. Hence, in embodiments in particular embodiments, the radiation exit window has an angle not equal to 0° and not equal to 180° with one or more of the side(s), in particular all side(s). Note that the angle a can be different for different side(s). For example, the tilted radiation exit window of a strip-shaped elongated body can have an angle a1 with a first side, an angle a2 = 180° - a1 with a second side, and an angle of 90° with the two other sides.

[0065] Hence, the (elongated) luminescent body can comprise, in embodiments, (n) side(s), comprising a first side comprising a radiation input face and a second side configured parallel to the first side, wherein the side(s) define a height (H). The first and second side are configured parallel to the luminescent body material there between, thereby defining a width of the luminescent body. The radiation input face is at least a part of the first face, which can be configured for receiving the light source light. The (elongated) luminescent body further comprises a radiation exit window bridging at least a part of the height (H) between the first and second side. In particular, the radiation exit window is comprised by the second face. Further embodiments are set out below. As mentioned above, in embodiments, the radiation exit window and the radiation input face have a plurality of angles (a) not equal to 0° and not equal to 180°. Still further, as also shown by the embodiments above, the radiation exit window has an angle not equal to 0° and not equal to 180° with one or more of the side(s).

[0066] The light-transmitting body has light guiding or wave guiding properties. Hence, the light-transmitting body is also denoted as a waveguide or lightguide herein. Since the light-transmitting body is used as a light concentrator, the light-transmitting body is also denoted as a light concentrator herein. The light-transmitting body will typically have (some) transmission of one or more of (N)UV, visible and (N)IR radiation in a direction perpendicular to the length of the light-transmitting body, such as in embodiments of at least visible light. The internal transmission of visible light can be close to 100% without an activator (dopant) such as trivalent cerium.

[0067] The light-transmitting body can have a transmittance for one or more luminescent wavelengths of at least 80% / cm, such as at least 90% / cm, even more particularly at least 95% / cm, such as at least 98% / cm, such as at least 99% / cm. This means that, for example, 1 cm 3 A light-transmitting body piece in the shape of a cube will have a transmittance of at least 95% under perpendicular illumination with radiation having a selected luminescent wavelength, such as a wavelength corresponding to an emission maximum of luminescence of a luminescent material of the light-transmitting body. Hence, the luminescent body is also referred to as a "light-transmitting body" herein, since this body is optically transmissive for the luminescent material light.

[0068] In this document, values for transmittance especially refer to transmittance without taking into account Fresnel losses at the interface (e.g. air). Hence, the term "transmittance" especially refers to internal transmittance. Internal transmittance can for example be determined by measuring the transmittance of two or more objects having different widths, at which the transmittance is measured. Based on such measurements, the contribution of Fresnel reflection losses and (thus) the internal transmittance can then be determined. Hence, in particular, the transmittance values referred to herein neglect Fresnel losses.

[0069] In embodiments, an anti-reflection coating can be applied to the luminescent body in order to suppress Fresnel reflection losses (during the light in-coupling process).

[0070] In addition to the high transmittance for the wavelength(s) of interest, the scattering for the wavelength(s) can also be particularly low. Hence, the mean free path for the wavelength of interest, taking only scattering effects into account (and thus not taking possible absorption into account, which should be low anyway considering the high transmittance), can be at least 0.5 times the length of the body, such as at least the length of the body, like at least twice the length of the body. For example, in embodiments, the mean free path taking only scattering effects into account can be at least 5 mm, such as at least 10 mm. The wavelength of interest can especially be the maximum emission wavelength of the luminescent material luminescence. The term "mean free path" especially refers to the average distance a ray will travel before experiencing a scattering event that will change its propagation direction.

[0071] The transmission can be determined by providing light at a certain wavelength with a first intensity under normal radiation to the light transmitting body, and correlating the intensity of the light of that wavelength measured after transmission through the material to the first intensity of the light provided to the material at that certain wavelength (see also E-208 and E-406 of the CRC Handbook of Chemistry and Physics, 69th edition, 1088-1989).

[0072] The light transmitting body can have any shape, such as a beam (or bar) shape or a rod shape, however especially a beam shape (cuboid shape). The light transmitting body (such as a light emitting concentrator) can be hollow (like a tube), or can be filled with another material (like a tube filled with water or a tube filled with another solid light transmitting medium). The present invention is not limited to a particular embodiment of shape, nor is the present invention limited to embodiments with a single exit window or out-coupling surface. In the following, some particular embodiments are described in more detail. If the light transmitting body has a circular cross-section, then the width and height can be equal (and can be defined as a diameter). However, especially, the light transmitting body has a cuboid shape (such as a bar shape), and is further configured to provide a single exit window.

[0073] In particular embodiments, the light transmitting body can especially have an aspect ratio larger than 1, i.e. a length larger than a width. Typically, the light transmitting body is a rod or bar (beam) or rectangular plate, although the light transmitting body does not necessarily have a square, rectangular or circular cross-section. Typically, the light source is configured to illuminate one (or more) longer face (side edge), denoted herein as a radiation input face, and radiation escapes from the face in front (front edge), denoted herein as a radiation exit window. The light source(s) can provide radiation to one or more side faces, and optionally to an end face. Hence, there can be more than one radiation input face. The radiation exit window can especially have an angle with the radiation input face which is not equal to 0° and not equal to 180°, such as an angle(s) of 90°. Further, in particular embodiments, the radiation exit window has an angle with one or more of the one or more side faces which is not equal to 0° and not equal to 180°, such as an angle(s) of 90°.

[0074] In particular, in embodiments, the solid state light source or other light source is not in (direct) physical contact with the light transmitting body.

[0075] In particular, in embodiments, the light transmitting body comprises a radiation input face and a radiation exit face, the radiation input face being configured in light receiving relationship with the first light source. In particular, in embodiments, the radiation input face and the radiation exit face are not the same part of the light transmitting body, although it is not excluded that the same face can be used to provide the radiation input face and the radiation exit face. In particular embodiments, different faces of the light transmitting body comprise the radiation exit face and the radiation input face (see also further below).

[0076] Hence, the light-transmitting body, more particularly its radiation input face, is configured downstream of the first light source. Or, in other words, the light-transmitting body, more particularly its radiation input face, is radiationally coupled with the first light source.

[0077] The term "radiationally coupled" or "optically coupled" can in particular mean that (i) the light generating element (such as the light source), and (ii) the other item or material are associated with each other such that at least part of the radiation emitted by the light-transmitting body is received by the item or material. In other words, the item or material is configured in a light-receiving relationship with the light-transmitting body. At least part of the radiation of the light-transmitting body will be received by the item or material. This can in embodiments be direct, such as the item or material being in physical contact with the light-emitting surface of the light-transmitting body. This can in embodiments be via a medium, such as air, a gas, or a liquid or solid light guiding material. In embodiments, one or more optical devices (such as lenses, reflectors, filters) can also be configured in the light path between the light-transmitting body and the item or material.

[0078] The terms "upstream" and "downstream" relate to the arrangement of items or features with respect to the propagation of light from a light generating component (here in particular the light source), wherein a second position in the light beam closer to the light generating component is "upstream" and a third position in the light beam further away from the light generating component is "downstream" relative to a first position within the light beam from the light generating component.

[0079] Hence, the light-transmitting body is in particular transmissive for at least part of the light source light propagating from the radiation input face to the radiation exit face. Further, the light-transmitting body is in particular further configured to convert part of the light source light propagating through the light-transmitting body into first luminescent material light. Light-transmitting bodies are known in the art, such as described in WO2006 / 054203, which is incorporated herein by reference.

[0080] As described above, the light-transmitting body is in particular configured to convert part of the light source light propagating through the light-transmitting body into first luminescent material light having a first luminescent material spectral power distribution different from the first light spectrum power distribution of the first light source light. The first luminescent material light can in particular be due to down-conversion, see also above.

[0081] In particular embodiments, the light transmissive body can especially have an aspect ratio larger than 1, i.e. a length larger than a width. Typically, the light transmissive body is a rod or bar (beam) or rectangular plate, although the light transmissive body does not necessarily have a square, rectangular or circular cross-section. Typically, the light source is configured to illuminate one (or more) longer face (side edge), denoted herein as a radiation input face, and radiation escapes from the face at the front face (front edge), denoted herein as a radiation exit window. The light source(s) can provide radiation to one or more side faces and optionally to an end face. Thus, there can be multiple radiation input faces. Typically rod- or bar-shaped light transmissive bodies can have any cross-sectional shape, but in embodiments have a square, rectangular, circular, elliptical, triangular, pentagonal or hexagonal cross-sectional shape. Typically, the ceramic or crystal is a cube. In particular embodiments, the body can be provided with a shape different from a cube, wherein the light input surface has a slightly trapezoidal shape. By doing so, the luminous flux can even be enhanced, which can be advantageous for some applications. Thus, in some cases (see also above), the term "width" can also refer to a diameter, such as in the case of a light transmissive body having a circular cross-section.

[0082] Especially for laser purposes, the light emitter can have a length larger than the height and / or width.

[0083] In embodiments, the light emitter is a single crystal.

[0084] The above with respect to the light emitter is described with respect to the first luminescent material, but can also apply to embodiments of the second luminescent material.

[0085] For laser applications, the light emitter comprising the (first) luminescent material can be configured between two mirrors. One of the mirrors (first mirror) can be configured upstream of the light emitter and downstream of the first light source, and can be transmissive for the first laser light source light at least in one direction, while being substantially reflective for the (first) luminescent material light propagating in the opposite direction. The other mirror (second mirror) can be configured at the other end of the light emitter, and can be considered to be configured downstream of the light emitter. This mirror can be partially reflective and partially transmissive for the (first) luminescent material light, such that the laser emission behavior can be facilitated and a first luminescent laser beam can escape from this mirror. In embodiments, the second mirror can also be reflective for the first laser. In embodiments, one or more of the mirrors can for example comprise a dichroic mirror.

[0086] Hence, especially these mirrors can be wavelength dependent. The first mirror upstream can be configured to transmit the pump light, but to substantially reflect the higher wavelengths, especially substantially all of the converted light. The second mirror downstream of the luminescent body can be configured to transmit a portion of the converted light. In embodiments, the portion of the converted light transmitted by the mirror can be in the range of e.g. 40-80% of the converted light. Especially, in embodiments, the wavelength dependent mirrors defining the cavity can have a reflection-transmission characteristic allowing for a final generation of a first luminescent material laser.

[0087] In this document, when an element is referred to as being transmissive, this can in embodiments mean that at one or more wavelengths, the portion transmitted can be larger than the portion reflected or absorbed. In this document, when an element is referred to as being reflective, this can in embodiments mean that at one or more wavelengths, the portion reflected can be larger than the portion transmitted or absorbed.

[0088] The above with respect to the first luminescent material (host) and its laser functionality can in embodiments also apply to the second luminescent material.

[0089] Especially, the optional second luminescent material is also provided as a luminescent body, such as a ceramic body or a single crystal body.

[0090] The term "spectral power distribution of the first light source light" and similar terms refer to the spectral power distribution of the first light source light. The term "spectral power distribution of the second light source light" and similar terms refer to the spectral power distribution of the second light source light. The term "spectral power distribution of the first luminescent material light" and similar terms refer to the spectral power distribution of the first luminescent material light. The term "spectral power distribution of the second luminescent material light" (see also below) and similar terms refer to the spectral power distribution of the second luminescent material light. The term "first light source light" and similar terms refer to the light of the first light source. The term "second light source light" and similar terms refer to the light of the second light source. In this document, the term "spectral power distribution" especially refers to the spectral power distribution in the visible wavelength range.

[0091] When there are multiple first light sources, they can especially all have substantially the same dominant wavelength. For example, assuming solid state light sources, they can in embodiments be identical bins. Assuming the first light sources emit first light source light in the visible light, the first light source light of the first light sources can be substantially identical. Hence, they can substantially have the same color point, and hence be substantially indistinguishable.

[0092] Similarly, when there are multiple second light sources, they can especially all have substantially the same dominant wavelength. For example, assume solid state light sources, which in embodiments can be identical bins. Assume that the second light sources emit second light source light in the visible light, the second light source light of the second light sources can be substantially the same. Hence, they can substantially have the same color point, and thus substantially no difference.

[0093] The first light source light and the second light source light have different spectral power distributions. Hence, they can have different color points and different dominant wavelengths. The reason for using the first light source and the second light source can be that the first light source can have a wavelength that is very suitable for pumping the first luminescent material, but does not have a spectral power distribution that can be used as a color component of the device light and / or does not have a spectral power distribution that can be used for pumping an optional second luminescent material.

[0094] In a particular embodiment, the color or color point of the first type of light and the second type of light can be different when the respective color points of the first type of light and the second type of light differ at least 0.01 for u' and / or at least 0.01 for v', even more particularly at least 0.02 for u' and / or at least 0.02 for v'. In yet a more specific embodiment, the respective color points of the first type of light and the second type of light can differ at least 0.03 for u' and / or at least 0.03 for v'. In this document, u' and v' are the color coordinates of light in the CIE 1976 UCS (Uniform Chromaticity Scale) diagram.

[0095] As further indicated above, the light generating device can especially be configured to generate (in one or more operational modes) device light. In one or more operational modes of the light generating device, the light generating device is configured to generate white device light comprising the first light source light, the optically filtered first luminescent material light, and the second light source light.

[0096] The phrase "the light generating device is configured to generate device light in one or more operational modes" and similar phrases are substantially equivalent to the phrase "the light generating device is configured to generate device light in one or more operational modes" and similar phrases.

[0097] A system, apparatus or device can perform an action in a "mode" or "operational mode" or "mode of operation" or "operational mode". Similarly, in a method, an action or stage or step can be performed in a "mode" or "operational mode" or "mode of operation". The term "mode" can also be indicated as "control mode". This does not exclude that the system, apparatus or device can also be adapted to provide another control mode or a plurality of other control modes. Similarly, this can not exclude that one or more other modes can be performed before and / or after performing the mode.

[0098] However, in embodiments, a control system can be available which is adapted to provide at least a control mode. If other modes are available, the selection of such a mode can be performed, inter alia, via a user interface, although other options, like performing a mode depending on a sensor signal or a (time) scheme, are possible. In embodiments, the operational mode can also refer to a system, device or apparatus which can only be operated in a single operational mode, i.e. “on” without further tunability. Thus, in embodiments, the control system can be controlled depending on one or more of an input signal of a user interface, a sensor signal (of a sensor) and a timer. The term “timer” can refer to a clock and / or a predetermined time scheme. See further below as well.

[0099] In particular, there can be multiple operational modes, such as at least two, like at least three, such as at least five, like at least 8, such as at least 16. The change between operational modes can be stepwise or stepless. The control can be analog or digital.

[0100] The term “control” and similar terms refer, inter alia, to at least determining a behavior of an element or supervising a running of an element. Thus, “control” and similar terms herein can, for example, refer to imposing a behavior on an element (determining a behavior or supervising a running of an element) etc., such as, for example, measuring, displaying, actuating, opening, moving, changing a temperature, etc. In addition thereto, the term “control” and similar terms can additionally include monitoring. Thus, the term “control” and similar terms can include imposing a behavior on an element as well as imposing a behavior on an element and monitoring the element. The control of an element can be done with a control system, which can also be indicated as “controller”. The control system and the element can thus be functionally coupled at least temporarily or permanently. The element can comprise the control system. In embodiments, the control system and the element can not be physically coupled. The control can be done via wired and / or wireless control. The term “control system” can also refer to multiple different control systems which are, inter alia, functionally coupled, and wherein, for example, one control system can be a master control system and one or more other control systems can be slave control systems. The control system can comprise or can be functionally coupled to a user interface.

[0101] The control system can also be configured to receive and execute instructions from a remote control. In embodiments, the control system can be controlled via an App on a device, such as a portable device, like a smartphone or cell phone, a tablet. Thus, the device does not have to be coupled to the lighting system, but can be (temporarily) functionally coupled to the lighting system.

[0102] Hence, in embodiments, the control system can also be configured to be controlled by an App on a remote device. In such embodiments, the control system of the lighting system can be a slave control system or control in slave mode. For example, the lighting system can be identified with a code, in particular a unique code for the respective 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 the (unique) code (input by a user interface with an optical sensor, e.g. a QR code reader). The lighting system can also comprise means for communicating with other systems or devices, such as based on Bluetooth, WIFI, ZigBee, BLE or WiMAX, or other wireless technologies.

[0103] The one or more heat sinks can be configured in thermal contact with one or more of: the first light source, the optional second light source, and the first luminescent material and the optional second luminescent material.

[0104] It can be desirable to (further) shape the device light into a device light beam. Alternatively or additionally, it can be desirable to (further) homogenize the device light (into homogenized device light). For this, optical elements can be used. Hence, in embodiments, the light generating device can also comprise optical elements configured to beam-shape the device light and / or configured to homogenize the device light. In particular, the optical elements are configured downstream of the first luminescent material. Further, the optical elements are configured downstream of the one or more first light sources and downstream of the second light source.

[0105] The optical elements can especially comprise a collimator for converting (‘collimating’) a light beam into a light beam having a desired angular distribution. Further, the optical elements can especially comprise a light-transmitting body comprising a radiation entrance window. Hence, the optical elements can be a body of light-transmitting material configured to collimate converter radiation from the luminescent body. In particular embodiments, the optical elements comprise a compound parabolic collimator, such as a CPC (compound parabolic concentrator). Large-scale collimators, such as large-scale CPCs, can especially be used to collimate (emit) radiation.

[0106] The optical elements can have a cross-section (perpendicular to the optical axis) that is identical in shape to the cross-section (perpendicular to the longest body axis, which is especially parallel to the radiation input face) of the luminescent body. For example, if the latter has a rectangular cross-section, the former can also have such a rectangular cross-section, although the dimensions can be different. Further, the dimensions of the optical elements can vary over its length (as it can have a beam-shaping function).

[0107] Further, the cross-sectional shape of the optical element can vary with position along the optical axis. In a particular configuration, the aspect ratio of a rectangular cross-section can vary, preferably monotonously, with position along the optical axis. In another preferred configuration, the shape of the cross-section of the optical element can vary from circular to rectangular, or vice versa, with position along the optical axis.

[0108] In embodiments, the light generating device can be configured to generate, in one or more operational modes (of the light generating device), white device light having a CRI of at least 85 and a CCT of at most 3500 K, such as at most 3200 K, such as at most 3100 K, such as at most 3000 K, like a CCT of at most 3000 K.

[0109] As mentioned above, the light generating device can further comprise a control system configured to control the first light source (light) and optionally the second light source (light). In particular embodiments, the control system is configured to control one or more optical properties of the device light, in particular in further embodiments in accordance with a user interface, a sensor signal and a timer. In particular embodiments, the one or more optical properties comprise a correlated color temperature and a color rendering index. In embodiments, in one or more control modes, the control system is configured to maintain the color rendering index above 85, in particular above 87, at a correlated color temperature below 3100 K. In yet another embodiment, in one or more control modes, the control system is configured to maintain the correlated color temperature in a range of 2700-3000 K. Within this range, the CRI can be maintained high, such as even above 85, or even about 90. In yet another particular embodiment, the CRI is at least 88, while the correlated color temperature is equal to or less than 3000 K.

[0110] The luminous efficiency of the device (light) can in embodiments be chosen from a range of 200-370 lm / W, like in embodiments about 230-370 lm / W, such as in particular embodiments 290-370 lm / W, such as 300-360 lm / W (lm = lumen).

[0111] In embodiments, the light generating device is configured to provide luminescence having a power emitted from an exit surface of the luminescence converter, the luminescence converter having a power density of 4 W / mm 2 , in particular at least 7 W / mm 2 , more in particular at least 9 W / mm 2 , even more in particular at least 13 W / mm 2 .

[0112] In yet another particular embodiment, the lighting device can be configured to provide luminescence in combination with blue and / or red laser light from the same surface as the luminescence providing white light having a luminance of at least 2000 lm / mm 2 , more particularly at least 3000 lm / mm 2 , even more particularly at least 6000 lm / mm 2 , wherein in particular the red laser light can be generated by luminescent material. In this context, "lm" refers to lumen.

[0113] In yet another aspect, the application also provides a lamp or luminaire comprising a light generating device as defined herein.

[0114] The lighting device may, for example, be part of or applied in an office lighting system, a home application system, a shop lighting system, a home lighting system, a spot lighting system, a spotlight lighting system, a theater lighting system, a fiber application system, a projection system, a self-lit display system, a pixelated display system, a segmented display system, a warning sign system, a medical lighting application system, an indication sign system, a decorative lighting system, a portable system, a car application, an (outdoor) road lighting system, a city lighting system, a greenhouse lighting system, horticulture lighting, digital projection or LCD backlighting. BRIEF DESCRIPTION OF DRAWINGS

[0115] Embodiments of the application will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which:

[0116] Figs. 1a-c schematically depict some examples;

[0117] Figs. 1d-g schematically depict some possible embodiments;

[0118] Figure 2 possible emission spectra of light generating devices are shown; and

[0119] Figure 3 Embodiments of a luminaire and a lamp are schematically depicted.

[0120] The drawings are not necessarily to scale. DETAILED DESCRIPTION

[0121] Fig. 1 schematically depicts an embodiment of a light generating device 1000. The light generating device 1000 comprises a first light source 110 configured to generate first light source light 111. The first light source light 111 has a first light source spectral power distribution. The first light source 110 comprises a first laser light source 10 configured to generate first laser light source light 11. An optical device 310 can be applied to provide a collimated beam of first laser light source light. The first laser light source 10 is especially a solid state laser, like a diode laser. The light generating device 1000 further comprises a first luminescent material 210 configured to convert at least part of the first light source light 111 into first luminescent material light 211 having a first luminescent material spectral power distribution with an emission at one or more wavelengths selected from the wavelength range of 590-780 nm.

[0122] The first light source 110 and the first luminescent material 210 are configured to generate first luminescent material laser light 1211 having a first luminescent material laser spectral power distribution comprising at least part of the first luminescent material light 211. To this end, the first luminescent material 210 can especially be provided as or consist of a ceramic body, or be provided as or consist of a single crystal. Further, the luminescent material, especially the luminescent body, can be configured between two optical elements 231, 232, especially (wavelength dependent) mirrors, to provide an optical cavity for the desired laser wavelength(s). Hence, especially, the luminescent material 210 can be configured in an optical cavity 230.

[0123] The first light source spectral power distribution and the first luminescent material laser spectral power distribution are mutually different.

[0124] Especially, the first luminescent material light 211 or more especially the first luminescent material laser light 1211 can be orange or red, especially red. Hence, the first luminescent material laser light 1211 can have an intensity at one or more wavelengths in the orange and / or red, especially at least in the range of 618-650 nm, such as 618-632 nm.

[0125] Hence, in embodiments, the first light source 110 and the first luminescent material 210 and optional first optical device (see below) are configured to generate first luminescent material laser light 1211 having a peak wavelength in the wavelength range of 618-650 nm, more especially in the wavelength range of 618-632 nm.

[0126] Especially, the first luminescent material light can have a dominant wavelength in the range of 618-650 nm, especially in the wavelength range of 618-632 nm.

[0127] In embodiments, the first luminescent material 210 can comprise an inorganic material doped with (trivalent) rare earth ions (capable of converting one or more of blue and UV radiation into visible light). For example, in embodiments, the first luminescent material 210 comprises Pr 3+ . In particular, in embodiments, the first luminescent material 210 can comprise Pr 3+ doped aluminate. For example, for such luminescent materials, especially the aluminate described herein, the dominant wavelength can be in the range of 618-632 nm, see also Figure 2 .

[0128] In particular embodiments, the first light source 110 is configured to generate blue first light source light 111. All such blue first light source light 111 can be converted, or part can be used to generate, for example, white device light 1001. In Fig. 1, the latter variant is schematically depicted.

[0129] In one or more operational modes of the light generating device 1000, the light generating device 1000 is configured to generate white device light 1001 comprising first luminescent material laser light 1211. To this end, the first luminescent material laser light 1211 and (remaining) blue first light source light can be applied. In addition, yellow and / or green light can have to be provided.

[0130] Fig. 1a schematically depicts an example in which, for example, a second light source 120 can be applied. Hence, in embodiments, a second light source 120 can be applied which is configured to generate second light source light 121 having a second light source spectral power distribution, wherein in embodiments, the second light source 120 comprises a second laser light source 20 configured to generate second laser light source light 21. Hence, the second light source light 121 can essentially consist of the second laser light source light 21.

[0131] Hence, the light generating device 1000 can in particular be configured to generate, in one or more operational modes (of the light generating device 1000), white device light 1001 comprising first light source light 111, first luminescent material laser light 1211 and (optionally) second light source light 121. More in particular, in embodiments, the device light 1001 can comprise, in one or more operational modes, first luminescent material laser light 1211 and (remaining) blue first light source light 111 and second laser light 21.

[0132] Further, the light generating device 1000 further comprises a control system 300 configured to control the plurality of first laser light sources 10, or can be functionally coupled to such control system 300.

[0133] Fig. lb schematically depicts a variant wherein one or more of the first light sources 110 (first luminescent material 210) and (optional) second optical device 432 are configured to generate a portion of the first light source light 111 that bypasses the first luminescent material 210. Hence, this first light source light can essentially comprise the first laser light 11. The optical device 432 can be a beam splitter or a mirror.

[0134] Further, as an example, an optional first optical device 431 is depicted. Such an optional first optical device 431 can be used as a filter to filter out undesired wavelengths. In this way, for example, a very narrow wavelength region of the laser wavelength can be selected. For example, for trivalent praseodymium, the transition 3 p0→ 3 H6.

[0135] Hence, in embodiments in one or more operational modes of the light generating device 1000, the light generating device 1000 is configured to generate white device light 1001 comprising first light source light 111 that bypasses the first luminescent material 210, first luminescent material laser light 1211 and (optionally) second light source light 121.

[0136] Fig. lc schematically depicts an embodiment similar to the example of Fig. la, however, here the light generating device 1000 comprises a plurality of first light sources 110 configured to generate first light source light 111. A portion of the first light source light can be mixed into the device light 1001 without contact with the first luminescent material 210.

[0137] Figs. Id and le schematically depict embodiments wherein the light generating device 1000 further comprises a second luminescent material 220. The second luminescent material 220 is configured to convert at least a portion of one or more of (a) first laser light source light 11 and (b) second light source light comprising second laser light source light 21 to provide second luminescent material light 221. In one or more operational modes of the light generating device 1000, the light generating device 1000 is configured to generate white device light 1001 comprising first luminescent material light 211 and second luminescent material light 221. Or, in other words (see also above), the light generating device 1000 is configured to generate white device light 1001 comprising first luminescent material laser light 1211 and second luminescent material light 211 in one or more operational modes of the light generating device 1000.

[0138] Fig. Id shows an embodiment in which the second luminescent material 220 is configured to convert at least part of the second light source light, including the second laser light source light 21, to provide second luminescent material light 221. Optionally, at least part of the second light source light 121 can remain unconverted. Hence, in one or more operational modes of the light generating device 1000, the light generating device 1000 is configured to generate white device light 1001 comprising the first light source light 111 bypassing the first luminescent material 210, the first luminescent material laser light 1211 and the second light source light 121 and the second luminescent material light 221.

[0139] Fig. le shows an embodiment comprising a plurality of first laser light sources 10 and in which the second luminescent material 220 is configured to convert at least part of the first laser light source light 11 to provide second luminescent material light 221. Hence, in one or more operational modes of the light generating device 1000, the light generating device 1000 is configured to generate white device light 1001 comprising the first light source light 11 bypassing the first luminescent material 210, the first luminescent material laser light 1211 and the second luminescent material light 221.

[0140] As indicated above, the luminescent material 220 can comprise (Y x1-x2-x3 A X2 Ce X3 )3(Al y1-y2 B y2 )5O 12 wherein xi+x2+x3=1, wherein x3>0, wherein 0

[0141] Fig. If schematically depicts an embodiment in which substantially a single type of first light source 110 can be applied. Here, the plurality of first laser light sources 10 and the first luminescent material 210 are configured to generate first luminescent material laser light 1211. Further, the plurality of first laser light sources 10 and the second luminescent material 220 are configured to generate second luminescent material light 121. Hence, in one or more operational modes of the light generating device 1000, the light generating device 1000 is configured to generate white device light 1001 comprising the first laser light source light 11, the first luminescent material laser light 1211 and the second luminescent material light 221.

[0142] Fig. 1g schematically depicts an embodiment in which the light generating system 1000 comprises a first group of one or more first laser light sources 10 configured to generate blue first laser light 11 that bypasses the first luminescent material 210 and the second luminescent material 220. Further, the light generating system 1000 comprises a second group of one or more first laser light sources 10 configured to generate blue first laser light 11 that illuminates the first luminescent material 210 but bypasses the second luminescent material 220. Yet further, the light generating system 1000 comprises a third group of one or more first laser light sources 10 configured to generate blue first laser light 11 that bypasses the first luminescent material 210 but illuminates the second luminescent material 220.

[0143] In a particular embodiment, the control system 300 is configured to control (individually) the plurality of first laser light sources 10.

[0144] For example, with reference to embodiments such as schematically depicted in Figs. 1a, 1b, 1c and 1d, the second light source 120 is configured to generate second light source light 121 having a second light source spectral power distribution, wherein the second light source 120 comprises a second laser light source 20 configured to generate second laser light source light 21. Further, the first light source spectral power distribution, the second light source spectral power distribution and the first luminescent material laser light spectral power distribution are mutually different. Yet further, the second light source 120 is configured to generate second light source light 121 having a second light source spectral power distribution, the second light source light having one or more wavelengths in the green and yellow wavelength range; and with reference to the embodiments schematically depicted in the foregoing figures, in one or more operational modes of the light generating device 1000, the light generating device 1000 is configured to generate white device light 1001 having a CRI of at least 85 and a CCT of at most 3200 K. The optical properties of the device can be controlled by the control system 300. In other operational modes, colored light, or light with a higher CCT, etc. can be provided.

[0145] A solid state light source can be controlled by controlling the power and / or by controlling the pulse width modulation of the power.

[0146] Figure 2 A spectral power distribution of an example of device light is shown, which spectral power distribution comprises a blue laser peak, a red laser peak from Pr 3+ and yellow / green from the garnet luminescent material.

[0147] In the following table, some examples of combinations of blue, green and red are given. In examples 1 to 3, as an example, Pr 3+ An emission spectrum in the range of 580-780 nm has been chosen as Sr 0.7 La 0.3 Mg0.3 Al 11.7 O 19 :Pr 3+ (ASL:Pr); although other materials are of course possible. In examples 4 to 8, the laser line (LL) has been narrowed to very specific wavelengths. The percentages are the radiometric contribution (in Watts) to the white spectrum.

[0148]

[0149]

[0150] The blue percentage indicates the contribution of blue to white light, and the relative B+R blue percentage indicates the percentage of the contribution of blue relative to blue and red.

[0151] Figure 3 Embodiments of a luminaire 2 comprising a light generating device 1000 as described above are schematically depicted. Reference 301 indicates a user interface, such as a graphical user interface, which can be functionally coupled to a control system 300 which is comprised by or functionally coupled to the lighting system 1000. Figure 3 Embodiments of a lamp 1 comprising a light generating device 1000 are also schematically depicted. The lamp 1 or luminaire 2 can also comprise other elements (such as optical elements). For example, the lamp 1 or luminaire 2 can comprise beam shaping optics or beam directing optics. In embodiments, the lamp 1 or luminaire 2 can comprise beam shaping elements. In embodiments, the luminaire 2 can comprise a light blocking grid or the like.

[0152] Thus, among others, it is proposed herein the use of a rare earth doped crystal which can give down conversion laser emission in the red region when excited by a blue laser. A part of the blue laser is then used to pump a cerium doped YAG phosphor and / or an alternative phosphor. The combination of the spontaneous emission light from the YAG, the stimulated emission from the red emitting crystal and the blue emitting laser can provide white light which can be close to or on the BBL, can have a CRI higher than 90, at e.g. a CCT lower than 3500 K, such as lower than 3000 K. In this way, the problem of different aging can be solved.

[0153] The term "a plurality" means two or more.

[0154] The terms "substantially" or "basically" and similar terms used herein will be understood by those skilled in the art. The term "substantially" or "basically" may also include embodiments with connotations such as "completely," "entirely," "all," etc. Therefore, in embodiments, the adjective "substantially" or "basically" may also be removed. Where applicable, the term "substantially" or "basically" may also refer to 90% or higher, such as 95% or higher, especially 99% or higher, even more especially 99.5% or higher, including 100%.

[0155] The term "comprising" also includes embodiments in which the term "comprising" means "consisting of".

[0156] The term “and / or” specifically refers to one or more 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 items 1 and 2. The term “comprising” in one embodiment may mean “consisting of…”, but in another embodiment it may also mean “containing at least the defined substance and optional one or more other substances.”

[0157] Furthermore, the terms first, second, third, etc., used in the specification and claims are used to distinguish similar elements and are not necessarily used to describe sequences or chronological order. It should be understood that such terms are interchangeable where appropriate, and the embodiments of the invention described herein can operate in sequences other than those described or illustrated herein.

[0158] The equipment, apparatus, or system described herein may, among other things, be used during operation. Those skilled in the art will appreciate that the invention is not limited to the method of operation, or the equipment, apparatus, or system in operation.

[0159] It should be noted that the above embodiments are illustrative and not limiting of the invention, and those skilled in the art will be able to devise many alternative embodiments without departing from the scope of the appended claims.

[0160] In the claims, any reference numerals placed in parentheses should not be construed as limiting the claims.

[0161] The use of the verb "comprising" and its variations does not exclude the presence of elements or steps other than those described in the claims. Unless the context clearly requires otherwise, throughout the specification and claims, the words "comprising," "containing," etc., should be interpreted in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is, in the sense of "including but not limited to."

[0162] The article "one" or "a" preceding an element does not preclude the existence of multiple such elements.

[0163] The application can be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the device claim or apparatus claim or system claim enumerating several parts, several of these parts can be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0164] The application also provides a control system, which can control a device, apparatus or system, or which can carry out a method or process as described herein. Still further, the application also provides a computer program product, which, when run on a computer functionally coupled to or comprised by a device, apparatus or system, controls one or more controllable elements of such device, apparatus or system.

[0165] The application also applies to a device, apparatus or system comprising one or more characterising features described in the description and / or shown in the attached drawings. The application further pertains to a method or process comprising one or more characterising features described in the description and / or shown in the attached drawings.

[0166] The various aspects discussed in this patent can be combined to provide further advantages. Further, those skilled in the art will appreciate that embodiments can be combined and also combined with more than two embodiments. Also, some features can form the basis of one or more divisional applications.

Claims

1. A light generating device (1000), wherein: - the light generating device (1000) comprises: (a) a first light source (110) configured to generate first light source light (111) having a first light source spectral power distribution, wherein the first light source (110) comprises a first laser light source (10) configured to generate first laser light source light (11); (b) a first luminescent material (210) configured to convert at least part of the first light source light (111) into first luminescent material light (211) having a first luminescent material spectral power distribution having emission at one or more wavelengths selected from the wavelength range of 590-780 nm, wherein the first luminescent material (210) is configured in an optical resonator (230); (c) a second light source (120) configured to generate second light source light (121) having a second light source spectral power distribution, wherein the second light source (120) comprises a second laser light source (20) configured to generate second laser light source light (21); and (d) a second luminescent material (220) configured to convert at least part of one or more of (i) the first laser light source light (11) and (ii) the second laser light source light (21) to provide second luminescent material light; - the first light source (110) and the first luminescent material (210) are configured to generate first luminescent material laser light (1211) having a first luminescent material laser spectral power distribution comprising at least part of the first luminescent material light (211); - the first light source spectral power distribution and the first luminescent material laser spectral power distribution are mutually different; - the light generating device (1000) is configured to generate white device light (1001) comprising the first luminescent material laser light (1211) and the second luminescent material light (221) in one or more operational modes; - and wherein the second luminescent material (220) comprises (Y x1-x2-x3 A X2 Ce X3 )3(Al y1-y2 B y2 )5O 12 wherein x1+x2+x3=1, wherein x3>0, wherein 0 x2+x3 0.2, wherein y1+y2=1, wherein 0 y2 0.2, wherein A comprises one or more elements selected from the group consisting of lanthanides and scandium, and wherein B comprises one or more elements selected from the group consisting of Ga and In, wherein at most 10% of the Al-O can be replaced by Si-N.

2. The light generating device (1000) according to claim 1, wherein the first luminescent material (210) comprises an inorganic material doped with rare earth ions, and wherein the optical resonator (230) is defined by two wavelength dependent mirrors (231, 232).

3. The light generating device (1000) according to claim 1 or 2, wherein the first luminescent material (210) comprises Pr 3+ doped aluminates.

4. The light generating device (1000) according to claim 1 or 2, wherein the first light source (110) and the first luminescent material (210) and optional first optical means (431) are configured to generate first luminescent material laser light (1211) having a peak wavelength in the wavelength range of 618-650 nm.

5. The light generating device (1000) according to claim 1 or 2, wherein the first light source (110) and the first luminescent material (210) and optional first optical means (431) are configured to generate first luminescent material laser light (1211) having a dominant wavelength in a wavelength range of 618 nm - 632 nm.

6. The light generating device (1000) according to claim 1 or 2, wherein the first light source (110) is configured to generate blue first light source light (111).

7. The light generating device (1000) according to claim 6, wherein the first luminescent material (210) is configured to absorb a part of the first light source light (111), and wherein the light generating device (1000) is configured to generate white device light (1001) in one or more operational modes, the white device light (1001) further comprising the first light source light (111).

8. The light generating device (1000) according to claim 6, comprising one or more first light sources (110) configured to generate the first light source light (111), wherein: - the one or more first light sources (110), the first luminescent material (210) and optional second optical means (432) are configured to generate a part of the first light source light (111) that bypasses the first luminescent material (210); and - the light generating device (1000) is configured to generate white device light (1001) in one or more operational modes, the white device light (1001) further comprising the first light source light (111) that bypasses the first luminescent material (210).

9. The light generating device (1000) according to any one of claims 1, 2, 7 and 8: - wherein the first light source spectral power distribution, the second light source spectral power distribution and the first luminescent material laser spectral power distribution are mutually different; - wherein the second light source (120) is configured to generate second light source light (121) having the second light source spectral power distribution, the second light source light (121) having one or more wavelengths in a green and yellow wavelength range; and - wherein the light generating device (1000) is configured to generate white device light (1001) in one or more operational modes, the white device light further comprising the first light source light (111) and the second light source light (121).

10. The light generating device (1000) according to any one of claims 1, 2, 7 and 8, wherein the second light source (120) is configured to generate blue second light source light (121).

11. The light generating device (1000) according to claim 10, wherein the second luminescent material (220) is configured to convert at least part of the first laser light source light (11) to provide second luminescent material light.

12. The light generating device (1000) according to claim 10, wherein: ​ - the first laser light source (10) and the first luminescent material (210) are configured to generate first luminescent material laser light (1211); - the first laser light source (10) and the second luminescent material (220) are configured to generate the second luminescent material light (221); and - the light generating device (1000) is configurable to generate, in one or more operational modes, white device light (1001) comprising the first laser light source light (11), the first luminescent material laser light (1211), and the second luminescent material light (221).

13. The light generating device (1000) according to claim 10, comprising a plurality of first laser light sources (10) configured to generate blue laser light (11), wherein: - a first group of one or more first laser light sources (10) is configured to generate blue first laser light (11) that bypasses the first luminescent material (210) and the second luminescent material (220); - a second group of one or more first laser light sources (10) is configured to generate blue first laser light (11) that illuminates the first luminescent material (210) but bypasses the second luminescent material (220); - a third group of one or more first laser light sources (10) is configured to generate blue first laser light (11) that bypasses the first luminescent material (210) but illuminates the second luminescent material (220); - the light generating device (1000) further comprises a control system (300) configured to control the plurality of first laser light sources (10).

14. The light generating device (1000) according to any one of claims 1, 2, 7, 8, 11, 12, and 13, wherein the light generating device (1000) is configured to generate, in one or more operational modes, white device light (1001) having a CRI of at least 85 and a CCT of maximum 3500 K.

15. A lamp (1) or luminaire (2) comprising the light generating device (1000) according to any one of claims 1 to 14.

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