Static phosphor and dynamic phosphor for producing high cri high-intensity light

Abstract

The invention provides light generating system (1000) comprising one or more light generating devices (100), a first luminescent material (210), a second luminescent material (220), a first support (810), and a second support (820), wherein: (A) the one or more light generating devices (100) are configured to generate device light (101); wherein the one or more light generating devices (100) comprise one or more solid state light sources (10) selected from laser diodes and superluminescent diodes; wherein the device light (101) comprises violet and / or blue light; (B) the first luminescent material (210) is configured to convert at least part of the device light (101) received by the first luminescent material (210) into first luminescent material light (211); wherein the first luminescent material (210) comprises a luminescent material of the type A3B5O12:Ce, wherein A comprises one or more of Y, La, Gd, Tb and Lu, and wherein B comprises one or more of Al, Ga, In and Sc; (C) the second luminescent material (220) is configured to convert at least part of the device light (101) received by the second luminescent material (220) into second luminescent material light (221); wherein the second luminescent material light (221) has a peak emission wavelength in the red wavelength range; (D) the first support (810) is configured to support the first luminescent material (210); the second support (820) is configured to support the second luminescent material (220); wherein the first support (810) is a stationary support and the second support (820) is a movable support, configured to move during a first operational mode of the light generating system (1000); (E) the light generating system (1000) is configured to generate system light (1001), wherein in a first operational mode of the light generating system (1000): the system light (1001) comprises (i) part of the device light (101), (ii) first luminescent material light (211), and (iii) second luminescent material light (221), and wherein the system light (1001) has a correlated color temperature selected from the range of 1500-10000 K and a color rendering index of at least 65.

Description

[0001] Static phosphor and dynamic phosphor for producing high CRI high-intensity light

[0002] FIELD OF THE INVENTION

[0003] The invention relates to a light generating system. The invention further relates to a lighting device comprising the light generating system.

[0004] BACKGROUND OF THE INVENTION

[0005] White light sources using a laser diode and a phosphor are known in the art. US2018 / 0316160, for instance, describes a device and a method for an integrated white colored electromagnetic radiation source using a combination of laser diode excitation sources based on gallium and nitrogen containing materials and light emitting source based on phosphor materials. A violet, blue, or other wavelength laser diode source based on gallium and nitrogen materials may be closely integrated with phosphor materials, such as yellow phosphors, to form a compact, high-brightness, and highly efficient, white light source. The phosphor material is provided with a plurality of scattering centers scribed on an excitation surface or inside bulk of a plate to scatter electromagnetic radiation of a laser beam from the excitation source incident on the excitation surface to enhance generation and quality of an emitted light from the phosphor material for outputting a white light emission either in reflection mode or transmission mode.

[0006] WO2016 / 037773A2 discloses a lighting device comprising a first UV solid state light source, a second blue solid state light source and a wavelength converter element. The wavelength converter element comprises a first green / yellow luminescent material and a second orange / red luminescent material, configured to be excited by the blue light.

[0007] US2017 / 198874A1 discloses a luminaire with an excitation light source. A first fluorescent plate is excited by the excitation light and has a first phosphor layer. A second fluorescent plate is arranged downstream of the excitation light with respect to the first fluorescent plate. The second fluorescent plate has a second phosphor layer having a wavelength conversion characteristic different from a wavelength conversion characteristic of the first phosphor layer. A support supports the first fluorescent plate and the second fluorescent plate such that at least one of relative positions and rotations of the first fluorescent plate and the second fluorescent plate are adjustable. SUMMARY OF THE INVENTION

[0008] High brightness light sources can be used in various applications including spots, projection, stage-lighting, headlamps, home and office lighting, entertainment lighting, and automotive lighting. For this purpose, laser-phosphor technology can be used, wherein a laser provides laser light and a remote phosphor converts laser light into converted light. A relatively straightforward way to produce white light using lasers is to use (blue) laser light in combination with a (yellow) phosphor to generate phosphor converted light. Laser-phosphor systems may allow generation of high brightness light and may therefore be used in projection systems, including displays such as cinema projectors and projectors for home, school, and office applications, car front lighting, search lighting, stage lighting, architectural lighting, and special lighting applications.

[0009] It appears desirable to provide a (warm-)white high-intensity light source which is able to provide light with a high intensity and a high CRI. For this purpose, it may be desired that a large percentage of light is emitted in the red part of the (visible) spectrum. Red phosphors, especially (oxy)nitrides may be susceptible to thermal quenching. Hence, a problem with high intensity light sources in combination with the application of luminescent materials may be the thermal stability and / or the temperature dependence of the luminescence of the luminescent material.

[0010] Further, there is a desire for color tunable lighting devices.

[0011] Hence, it is an aspect of the invention to provide an alternative light generating system, which preferably further at least partly obviates one or more of above-described drawbacks. The present invention may have as object to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.

[0012] It may be desired to keep the temperature of the red phosphor relatively low, e.g. through the use of a phosphor wheel. Furthermore, color tuneability can be achieved using different luminescent materials, such as a combination of a green-yellow garnet phosphor and a red phosphor. However, adding the green-yellow garnet phosphor (e.g. YAG / LuAG), which can be pumped to higher intensities and temperatures than the red phosphor, to a phosphor wheel together with the red phosphor may increase the temperature of the wheel and thus of the red phosphor, which may be undesirable.

[0013] According to a first aspect, the invention provides a light generating system comprising one or more light generating devices, a first luminescent material, a second luminescent material, a first support, and a second support. In embodiments, the one or more light generating devices may be configured to generate device light. Further, in embodiments, the one or more light generating devices may comprise one or more solid state light sources selected from laser diodes and superluminescent diodes. Furthermore, in embodiments, the device light may comprise blue light. Additionally or alternatively, in embodiments, the device light may comprise violet light. In further embodiments, the first luminescent material may be configured to convert at least part of the device light received by the first luminescent material into first luminescent material light. Especially, the first luminescent material may comprise a luminescent material of the type AsBsO^Ce. Moreover, in embodiments, A may comprise one or more of Y, La, Gd, Tb and Lu. Moreover, in embodiments, B may comprise one or more of Al, Ga, In and Sc. Further, in embodiments, the second luminescent material may be configured to convert at least part of the device light received by the second luminescent material into second luminescent material light. Especially, the second luminescent material light may have a peak emission wavelength in the (orange-)red wavelength range. In embodiments, the first support may be configured to support the first luminescent material. Moreover, in embodiments, the second support may be configured to support the second luminescent material. Especially, the first support may be a stationary support and the second support may be a movable support, configured to move during a first operational mode of the light generating system. Moreover, in embodiments, the light generating system may be configured to generate system light. In further embodiments, in a first operational mode of the light generating system: the system light may comprise (one or more of) (i) part of the device light, (ii) first luminescent material light, and (iii) second luminescent material light. Moreover, in embodiments, the system light may have a correlated color temperature selected from the range of 1500-10000 K and / or a color rendering index of at least 65. Hence, in embodiments, the invention provides a light generating system comprising one or more light generating devices, a first luminescent material, a second luminescent material, a first support, and a second support, wherein: (A) the one or more light generating devices are configured to generate device light; wherein the one or more light generating devices comprise one or more solid state light sources selected from laser diodes and superluminescent diodes; wherein the device light comprises violet and / or blue light; (B) the first luminescent material is configured to convert at least part of the device light received by the first luminescent material into first luminescent material light; wherein the first luminescent material comprises a luminescent material of the type AsBsOn Ce, wherein A comprises one or more of Y, La, Gd, Tb and Lu, and wherein B comprises one or more of Al, Ga, In and Sc; (C) second luminescent material is configured to convert at least part of the device light received by the second luminescent material into second luminescent material light; wherein the second luminescent material light has a peak emission wavelength in the red wavelength rang; (D) the first support is configured to support the first luminescent material; the second support is configured to support the second luminescent material; wherein the first support is a stationary support and the second support is a movable support, configured to move during a first operational mode of the light generating system; (E) the light generating system is configured to generate system light, wherein in a first operational mode of the light generating system: the system light comprises (one or more of) (i) part of the device light, (ii) first luminescent material light, and (iii) second luminescent material light, and wherein the system light has a correlated color temperature selected from the range of 1500-10000 K and a color rendering index of at least 65.

[0014] With the present invention, a (dynamic) movable support (such as e.g. a phosphor wheel) may comprise a second luminescent material and may during operation move (e.g. under the moving action of a moving device (like a linear actuator or a rotary actuator). As such, the effect on the local (and temporal) peak temperature in the second luminescent material may be reduced, i.e., leading to good heat spreading and cooling properties. The (dynamic) movable support may, in such as system, be combined with a static support comprising a first luminescent material. Hence, such a system may be used in providing high lumen-output and high-intensity light for various applications such as projection and stage-lighting, among other applications. Hence, in this way, the invention may provide amongst others a laser-based high-brightness light source(s) using a static and a dynamic phosphor support. Moreover, different luminescent materials may be configured on (or within) the static and dynamic supports, which may be used to tune or control the spectral properties of the generated light, thereby providing color tunability. In view of thermal capacity, the dynamic support may be relatively large, whereas the static support may be smaller, see also further below. Hence, the invention may provide a combination of a staticsmall green-yellow garnet phosphor and a dynamic-large (oxy)nitride red phosphor in order to produce a warm-white high-intensity light source with a high CRI. Further, such system may allow control of spectral power distribution of the system light (of a high power system). Yet, such system may in a safe way provide high power light. The system may be relatively compact.

[0015] The light generating system (or “system”) may thus comprise one or more light generating devices, a first luminescent material, a second luminescent material, a first support, and a second support. The light generating system may thus apply light generating devices to irradiate a static (green-yellow) luminescent material and a (red) dynamic luminescent material such that (warm-)white light may be produced having high-intensity and a high CRI. Here below, embodiments of the different components of the light generating system will be described in further detail.

[0016] In embodiments, the light generating system may (thus) comprise at least one light generating device, such as at least two light generating devices, like at least three light generating devices. Hence, in specific embodiments, the light generating system may comprise a plurality of light generating devices.

[0017] Especially, the one or more light generating devices may be configured to generate device light. In embodiments, the device light may have a wavelength selected from the visible wavelength range (i.e. 380-780 nm). Especially, in embodiments, the device light may comprise violet and / or blue light, i.e., the device light may have a wavelength selected from the violet and / or blue wavelength range. In specific embodiments, the device light may comprise blue light. Especially, in such embodiments, the device light may essentially consist of blue light, i.e., >85%, such as >90% including 100% of the spectral power of the device light may be in the blue wavelength range. Additionally or alternatively, in specific embodiments, the device light may comprise violet light. Especially, in such embodiments, the device light may essentially consist of violet light, i.e., >85%, such as >90% including 100% of the spectral power of the device light may be in the violet wavelength range. In further specific embodiments, the device light comprises violet and blue light. Especially, in such embodiments, the device light may essentially consist of violet and blue light.

[0018] The terms “blue light” or “blue emission”, and similar terms, may especially relate to light having a wavelength in the range of about 440-490 nm (including some violet and cyan hues). However, intensity at shorter wavelengths may also be possible, such as within the wavelength range of 400-440 nm. Using violet device light may provide the advantage of an increase in color rendering index (CRI) of the (white) system light, as violet light may encompass a broader range of visible wavelengths, and may have a less intense blue peak wavelength than would be the case when using blue light. Furthermore, light generating devices providing violet device light may be less affected by droop than light generating devices providing blue device light. On the other hand, using blue device light may provide the advantage of a more energy-efficient light generating device, as the production of blue device light requires less power while still providing efficient light output. Especially, in embodiments the device light has a peak wavelength selected from the blue wavelength range. However, in alternative embodiments, the device light may also have a wavelength selected from the IR or UV wavelength ranges. Moreover, in embodiments the one or more light generating devices may comprise one or more solid state light sources. In embodiments, the one or more light sources may be configured to generate light source light. Especially, the one or more light generating devices may comprise one or more solid state light sources selected from laser diodes and superluminescent diodes, see also further below. In embodiments, the device light may comprise the light source light. In specific embodiments, the device light may essentially be the light source light.

[0019] Further, the light generating system may comprise luminescent materials. Especially, the light generating system comprises a first luminescent material. The term “first luminescent material” may also refer to a plurality of first luminescent materials (see also below). Further, the light generating system may also comprise a second luminescent material. The term “second luminescent material” may also refer to a plurality of second luminescent materials (see also below). Embodiments of luminescent materials are described below.

[0020] In embodiments, the first luminescent material may be configured in a lightreceiving relationship with at least one of the one or more light generating devices, i.e., the first luminescent material may be configured downstream of at least one of the one or more light generating devices. As such, in embodiments, the first luminescent material may be configured to convert at least part of the device light received by the first luminescent material into first luminescent material light.

[0021] The terms “upstream” and “downstream” relate to an arrangement of items or features relative to the propagation of the light from a light generating means (here the especially the light source), wherein relative to a first position within a beam of light from the light generating means, a second position in the beam of light closer to the light generating means is “upstream”, and a third position within the beam of light further away from the light generating means is “downstream”.

[0022] The phrase “... light received by ...”, and similar phrases, such as “device light received by the first luminescent material” may especially indicate that when the light is actually received by an item, an action may take place. Whether the light is received by the item, may e.g. depend upon the operational mode of the system. For instance, dependent upon the polarization of the light and / or the spectral power distribution of the light, the light may be irradiate the item, upon which the action may take place. The action may in embodiments be one or more of conversion, reflection, and transmission.

[0023] Hence, the action may also include refraction. The phrase “to convert at least part of the device light received by the first luminescent material into first luminescent material light”, and similar phrases, may thus indicate that when at least part of device light indeed irradiates the first luminescent material (in an operational mode of the light generating system), then at least part of that device light may be converted into first luminescent material light. Likewise, this may apply to other luminescent materials.

[0024] In embodiments, the first luminescent material may be configured to convert at least 60%, such as at least 70%, like at least 80% of the device light received (and absorbed) by the first luminescent material into first luminescent material light. Especially, in embodiments, the first luminescent material may be configured to convert at least 90%, more especially at least 95%, including essentially 100% (see also further below) of the device light received (and absorbed) by the first luminescent material into first luminescent material light. Further, in embodiments, the first luminescent material may be configured to convert at most 100%, such as at most 98%, like at most 95% of the device light received (and absorbed) by the first luminescent material into first luminescent material light. Especially, in embodiments, the first luminescent material may be configured to convert at most 90%, more especially at most 85% of the device light received (and absorbed) by the first luminescent material into first luminescent material light. In embodiments when the first luminescent material may be configured in the transmissive mode (see also further below), the first luminescent material may be configured to absorb (and thus convert) less than 100% of the device light received by the first luminescent material. In such embodiments, the nonabsorbed part of the device light received by the first luminescent material may e.g. be transmitted or reflected. For example, in embodiments, the first luminescent material may be configured to absorb between 60-100% and transmit (or reflect) between 0-40% of the device light received by the first luminescent material. Especially, in embodiments, the first luminescent material may be configured to (i) absorb between 70-99%, such as between 80- 98%, of the device light received by the first luminescent material and (ii) transmit (or reflect) between 1-30%, such as between 2-20% of the device light received by the first luminescent material.

[0025] Especially, the first luminescent material is configured to convert at least part of the light source light into first luminescent material light, wherein the first luminescent material may comprise a (garnet) luminescent material of the type AsBsOn Ce, wherein A comprises one or more of Y, La, Gd, Tb and Lu, and wherein B comprises one or more of Al, Ga, In and Sc. Hence, the first luminescent material light may e.g. be green light or yellow light (or in specific embodiments even orange (dependent upon the composition of the garnet and cerium concentration)). However, other embodiments are also possible, see below. In embodiments, 0.05-10% of the A elements comprise Ce, even more especially 0.05-5%, such as 0.1-5%. Especially, embodiments, 0.1-3% of the A elements comprise Ce, such as up to 2%, like selected from the range of 0.1-1.5%, such as at least above 0.5%.

[0026] Especially, a luminescent material comprises conversion material or is a conversion material. A luminescent material converts light from a light source, such as the light source light, into secondary light (here the luminescent material light). The luminescent material may comprise an organic group that converts the light, or a molecule that converts the light, or an inorganic group that converts the light, etc. Such groups (or molecule) may be indicated as converter element. The garnet type material as indicated above, comprises cerium (Ce) as converter element. Cerium comprising garnets are well known in the art.

[0027] Hence, in specific embodiments the first luminescent material comprises a luminescent material of the type AsBsOn Ce, wherein A in embodiments comprises one or more of Y, La, Gd, Tb and Lu, especially (at least) one or more of Y, Gd, Tb and Lu, and wherein B in embodiments comprises one or more of Al, Ga, In and Sc. Especially, A may comprise one or more of Y, Gd and Lu, such as especially one or more of Y and Lu. Especially, B may comprise one or more of Al and Ga, more especially at least Al, such as essentially entirely Al. Hence, especially suitable luminescent materials are cerium comprising garnet materials. Embodiments of garnets especially include A3B5O12 garnets, wherein A comprises at least yttrium or lutetium and wherein B comprises at least aluminum. Such garnets may be doped with cerium (Ce), with praseodymium (Pr) or a combination of cerium and praseodymium; especially however with Ce. Especially, B comprises aluminum (Al), however, B may also partly comprise gallium (Ga) and / or scandium (Sc) and / or indium (In), especially up to about 20% of Al, more especially up to about 10 % of Al (i.e. the B ions essentially consist of 90 or more mole % of Al and 10 or less mole % of one or more of Ga, Sc and In); B may especially comprise up to about 10% gallium. In another variant, B and O may at least partly be replaced by Si and N. The element A may especially be selected from the group consisting of yttrium (Y), gadolinium (Gd), terbium (Tb) and lutetium (Lu). Further, Gd and / or Tb are especially only present up to an amount of about 20% of A. In a specific embodiment, the garnet (first) luminescent material comprises (Yi-xLux)3B50i2:Ce, wherein x is equal to or larger than 0 and equal to or smaller than 1. The term “:Ce”, indicates that part of the metal ions (i.e. in the garnets: part of the “A” ions) in the luminescent material is replaced by Ce. For instance, in the case of (Yi.xLux)3A150i2:Ce, part of Y and / or Lu is replaced by Ce. This is known to the person skilled in the art. Ce will replace A in general for not more than 10%; in general, the Ce concentration will be in the range of 0.1 to 4%, especially 0.1 to 2% (relative to A). Assuming 1% Ce and 10% Y, the full correct formula could be (Yo.iLuo.sgCeo.o sALOn. Ce in garnets is substantially or only in the trivalent state, as is known to the person skilled in the art.

[0028] In embodiments, the first luminescent material (thus) comprises A3B5O12 wherein in specific embodiments at maximum 10% of B-0 may be replaced by Si-N.

[0029] In specific embodiments the first luminescent material comprises (YXI-X2-X3A’X2CeX3)3(Alyi-y2B’y2)5Oi2, wherein xl+x2+x3=l, wherein x3>0, wherein 0<x2+x3<0.2, wherein yl+y2=l, wherein 0<y2<0.2, wherein A’ comprises one or more elements selected from the group consisting of lanthanides, and wherein B’ comprises one or more elements selected from the group consisting of Ga, In and Sc. In embodiments, x3 is selected from the range of 0.001-0.1. In the present invention, especially xl>0, such as >0.2, like at least 0.8. Garnets with Y may provide suitable spectral power distributions.

[0030] In specific embodiments at maximum 10% of B-0 may be replaced by Si-N. Here, B in B-0 refers to one or more of Al, Ga, In and Sc (and O refers to oxygen); in specific embodiments B-0 may refer to Al-O. As indicated above, in specific embodiments x3 may be selected from the range of 0.001-0.04. Especially, such luminescent materials may have a suitable spectral distribution (see however below), have a relatively high efficiency, have a relatively high thermal stability, and allow a high CRI (optionally in combination with (the) light of other sources of light as described herein). Hence, in specific embodiments A may be selected from the group consisting of Lu and Gd. Alternatively or additionally, B may comprise Ga. Hence, in embodiments the first luminescent material comprises (YXI-X2-X3(Lu,Gd)X2CeX3)3(Alyi-y2Gay2)5Oi2, wherein Lu and / or Gd may be available. Even more especially, x3 is selected from the range of 0.001-0.1, wherein 0<x2+x3<0.1, and wherein 0<y2<0.1. Further, in specific embodiments, at maximum 1% of B-0 may be replaced by Si- N. Here, the percentage refers to moles (as known in the art); see e.g. also EP3149108. In yet further specific embodiments, the luminescent material comprises (Yxi-X3CeX3)3A150i2, wherein xl+x3=l, and wherein 0<x3<0.2, such as 0.001-0.1.

[0031] In specific embodiments, the first luminescent material may only include luminescent materials selected from the type of cerium comprising garnets. In even further specific embodiments, the first luminescent material includes a single type of luminescent materials, such as (¥xi-X2-x3A’X2CeX3)3(Alyi-y2B’y2)5Oi2. Hence, in specific embodiments the first luminescent material comprises luminescent material, wherein at least 85 weight%, even more especially at least about 90 wt.%, such as yet even more especially at least about 95 weight % of the luminescent material comprises (Yxi-X2-X3A’X2CeX3)3(Alyi-y2B’y2)5Oi2. Here, wherein A’ comprises one or more elements selected from the group consisting of lanthanides, and wherein B’ comprises one or more elements selected from the group consisting of Ga, In and Sc, wherein xl+x2+x3=l, wherein x3>0, wherein 0<x2+x3<0.2, wherein yl+y2=l, wherein 0<y2<0.2. Especially, x3 is selected from the range of 0.001-0.1. Note that in embodiments x2=0. Alternatively or additionally, in embodiments y2=0.

[0032] In specific embodiments, A may especially comprise at least Y, and B may especially comprise at least Al.

[0033] Alternatively, in specific embodiments, the first luminescent material may comprise the luminescent material of the type AsBsOn Ce, wherein A comprises for at least 55 at%, like at least 60 at% Lu, such as at least 67 at% Lu. Further, in embodiments, the first luminescent material may comprise the luminescent material of the type AsBsOn Ce, wherein A comprises for at least 70 at%, especially at least 75 at%, more especially at least 80 at% Lu. In specific embodiments, the first luminescent material may comprise the luminescent material of the type AsBsOn Ce, wherein A comprises at least 95 at%, such as at least 98 at%, like at least 99 at%, including essentially 100 at% Lu. Hence, in embodiments, the first luminescent material may comprise a luminescent material configured to provide green luminescent material light (such as e.g. LuAG).

[0034] The first luminescent material light may have a spectral power distribution with at least intensity in the visible wavelength range. Especially, in embodiments, the first luminescent material light may have a spectral power distribution with a peak emission wavelength in the green-yellow wavelength range. The terms “green-yellow wavelength range” or “green-yellow light” especially relate to light having a peak emission wavelength in the range of about 495-590 nm. Hence, in embodiments, the first luminescent material may be configured to generate green-yellow first luminescent material light.

[0035] In embodiments, the second luminescent material may (also) be configured in a light-receiving relationship with at least one of the one or more light generating devices, i.e., the second luminescent material may be configured downstream of at least one of the one or more light generating devices. As such, in embodiments, the second luminescent material may be configured to convert at least part of the device light received by the second luminescent material into second luminescent material light. In embodiments, the second luminescent material may be configured to convert at least 60%, such as at least 70%, like at least 80%, especially at least 90%, more especially at least 95%, including 100% of the device light received by the second luminescent material into second luminescent material light. Further, in embodiments, the second luminescent material may be configured to convert at most 100%, such as at most 98%, like at most 95%, especially at most 90%, more especially at most 85% of the device light received by the second luminescent material into second luminescent material light.

[0036] Moreover, in embodiments, the first luminescent material and / or the second luminescent material may be configured in a full-conversion mode. Hence, in embodiments, the first luminescent material and / or the second luminescent material may be configured to convert at least 95%, such as at least 98%, like at least 99% of the device light received (and absorbed) by the respective luminescent material. Especially, in embodiments, the first luminescent material and / or the second luminescent material may be configured to convert at least 99.5%, more especially at least 99.8%, including essentially 100% of the device light received (and absorbed) by the respective luminescent material.

[0037] The second luminescent material light may have a spectral power distribution with at least intensity in the visible wavelength range. Especially, in embodiments, the second luminescent material light may have a spectral power distribution with a peak emission wavelength in the orange-red wavelength range. More especially, in embodiments, the second luminescent material light may have a peak emission wavelength in the red wavelength range. The terms “orange-red wavelength range” or “orange-red light” especially relate to light having a peak emission wavelength in the range of about 590-780 nm. Examples and further embodiments of the luminescent materials are described further below.

[0038] As described above, the first luminescent material light may have a peak emission wavelength selected from the green-yellow wavelength range, i.e., the first luminescent material light may have a first peak emission wavelength ( pi) selected from the green-yellow wavelength range. Conversely, the second luminescent material light may have a peak emission wavelength selected from the (orange-)red wavelength range, i.e., a second peak emission wavelength ( p2) different from the first peak emission wavelength ( pi). In embodiments, the second peak emission wavelength ( p2) may be larger than the first peak emission wavelength ( pi), i.e., Ai>i<ki>2. Especially, in embodiments, | p2- pi |>20 nm, such as |kp2-kpi|>30 nm. For example, in embodiments, | p2- pi| may be selected from the range of 25-120 nm, such as from the range of 35-100 nm. In embodiments, the first luminescent material and the second luminescent material may both be supported by a support, such as configured on (or even into) a support. Therefore, in embodiments, the light generating system may comprise the first support and the second support. The first support may, in embodiments, be configured to support the first luminescent material. For example, in embodiments, the first luminescent material may be configured physically attached to and / or incorporated into the first support. Similarly, the second support may, in embodiments, be configured to support the second luminescent material. For example, in embodiments, the second luminescent material may be configured physically attached to and / or incorporated into the second support.

[0039] In embodiments, the first support and the second support may especially be separate components. However, in some embodiments, the first support and the second support may be combined into essentially the same component. For example, in embodiments, the combined component may comprise a static center (i.e., the first / static support) with a rotating element (i.e. the second / movable support) configured to rotate around the static center. Hence, in some embodiments, the first support and the second support may essentially be the same support. However, in specific embodiments, the first support and the second support may be individual separate components.

[0040] The (first and / or second) support may, in embodiments, comprise a rigid support. For example, in embodiments, the (first and / or second) support may comprise one of the group comprising: a plate, a disc, a tile, a block, a rod, a wheel, etc. Additionally or alternatively, in embodiments, the (first and / or second) support may comprise a flexible support. For example, in embodiments, the (first and / or second) support may comprise one of the group comprising: a (flexible) printed circuit board (PCB), a (LED) strip, a fabric support, etc.

[0041] In embodiments, the first support may be a stationary support. Such embodiments may be beneficial as it may be relatively easy to configure a stationary support in thermal contact with a thermally conductive element, such as a heat sink (see also further below). In some embodiments, the stationary support may (even) essentially be a thermally conductive element. However, in embodiments, the first support may be (alternatively) a movable support. Especially, in embodiments, the first support may be a movable support configured to move during an operational mode of the light generating system. Here, the terms “move” or “movable” and similar terms may refer to an object being or being able to be displaced in one or more of a lateral direction, a transverse direction, and a rotational direction. Hence, in embodiments, the first support may be a movable support. Especially, in embodiments, the first support may be a rotatable support. In such embodiments, the first support may be configured to move during an operational mode of the light generating system.

[0042] Similarly, in embodiments, the second support may be a stationary support. Alternatively, in embodiments, the second support may be a movable support. Especially, in embodiments, the second support may be a movable support configured to move during an operational mode of the light generating system. Here, the terms “move” or “movable” and similar terms may refer to an object being or being able to be displaced in one or more of a lateral direction, a transverse direction, and a rotational direction. Hence, in embodiments, the second support may be a movable support. Especially, in embodiments, the second support may be a rotatable support. In such embodiments, the second support may be configured to rotate during an operational mode of the light generating system.

[0043] Hence, in embodiments, the (first and / or second) support may comprise a movable support. In embodiments, the movable support may be comprised by a wheel-type support, a cylinder-type support, or a conveyor-belt type support. For example, in embodiments, the movable support may comprise a phosphor wheel or a phosphor rod. Alternatively, in embodiments, the movable support may be comprised by a cone-type support.

[0044] In specific embodiments, the first support may be a stationary support and the second support may be a movable support configured to rotate during a first operational mode of the light generating system. With high power irradiation of the luminescent material, the thermal load may become critical. Hence, in embodiments, the luminescent material (of the first and second luminescent material) that may be more sensitive to temperature and of which the intensity may decrease with the increase of temperature may be configured on the movable support.

[0045] Hence, in embodiments the (second) luminescent material may be configured to extend in a circular configuration, such as on a disc, and may be rotated during operation of the system. In this way, the (second) luminescent material surface may be extended so that during the operation heat load per unit area on the (second) luminescent material may be reduced, therewith keeping the temperature increase relatively low. Hence, in embodiments the (second) support may comprise a rotatable support, wherein the rotatable support comprises the (second) luminescent material; wherein during operation of the light generating system (in the first operational mode) the rotatable support rotates, such that over time different parts of the (second) luminescent material are irradiated by the device light. Rotational frequencies may e.g. be selected from the range of 40-300 Hz, like at least 50 Hz, though other rotational frequencies may also be possible. Hence, the surface of the (second) luminescent material subjected to laser radiation averaged over time (effective surface area) may be much larger than the surface which would be irradiated if the phosphor plate would be stationary. Typically, the effective surface area of the (second) luminescent material may be much greater (> lOx, more commonly > 50x) than the effective surface area of the (first) luminescent material. In embodiments, the rotatable element may be provided as wheel or disc. Hence, in embodiments the rotatable support may comprise a phosphor wheel.

[0046] However, rotating rods may also be applied.

[0047] The light generating system may, in embodiments, further comprise a moving device configured to move, especially rotate, the (first and / or) second support. In embodiments, the moving device may comprise an actuator, such as a linear actuator or a rotary actuator. Especially, in embodiments, the moving device may comprise a motor. In embodiments, the moving device may be comprised by the (first and / or) second support, i.e., the second support and the moving device may be combined in one component. Alternatively, in embodiments, the moving device may comprise a separate component from the (first and / or) second support.

[0048] In further embodiments, the movable support may comprise a phosphor track comprising the luminescent material. Especially, in embodiments, the luminescent material may be embedded into the movable support. Alternatively, in embodiments, the luminescent material may be provided as a layer on the movable support. In specific embodiments, the (first or) second support may be a movable support comprising a phosphor track comprising the (first or) second luminescent material. Especially, in embodiments, the movable support may be configured to allow both a (blue) device light contribution and a luminescent material contribution to propagate from the movable support. Therefore, in embodiments, the movable support may comprise a(n at least partially) transparent support. Especially, in embodiments, the movable support may comprise a transparent support which may comprise a phosphor track comprising luminescent material. Further, in embodiments, the movable support may be thermally conducting, e.g. the movable support may be or be comprised by a metal, sapphire, or ceramic disc. Furthermore, in embodiments, the movable support may comprise an opening. For example, in embodiments, the opening may comprise one of a pinhole, a slit, a (partially) circular slit, and a cavity. In embodiments, the movable support may even comprise two or more openings, such as two openings. Especially, in embodiments, the opening may be configured to transmit (blue) device light through the opening such that it may irradiate the luminescent material. More especially, in embodiments, at least part of the (blue) device light received by the movable support may be transmitted by the opening to the stationary support. In such embodiments, at least 5% of the (blue) device light, received by the movable support may be transmitted to the stationary support, such as at least 10%, like at least 30%, especially at least 30%. Furter, in such embodiments, at most 95% of the (blue) device light received by the movable support may be transmitted to the stationary support, such as at most 90%, like at most 80%, especially at most 70%.

[0049] In embodiments, the opening may comprise a physical hole or a (blue) device light transmissive material. Furthermore, in embodiments, the opening may have an opening dimension, such as e.g. a diameter Do or a width Wo (defined in a plane perpendicular to an optical axis of light received by the opening). In specific embodiments, the opening may have an opening cross-sectional area Ao (defined in a plane perpendicular to an optical axis of light received by the opening). Similarly, the movable support may have a support cross- sectional area As (defined in the plane perpendicular to an optical axis of light received by the opening). In embodiments, the opening cross-sectional area Ao may comprise at most 20%, like at most 10%, such as at most 5%, especially at most 3%, more especially at most 2% of a cross-sectional area of the movable support in the same plane of the movable support. In specific embodiments, the opening may have a cross-sectional equivalent circular diameter Do of at least 1 mm, such as at least 2 mm, like at least 5 mm. The equivalent circular diameter (or ECD) (or “circular equivalent diameter”) of an (irregularly shaped) two- dimensional shape is the diameter of a circle of equivalent area. For instance, the equivalent circular diameter of a square with side a is 2*a*SQRT(l / 7t). For a circle, the diameter is the same as the equivalent circular diameter. Would a circle in an xy-plane with a diameter D be distorted to any other shape (in the xy-plane), without changing the area size, then the equivalent circular diameter of that shape would be D. Alternatively, in specific embodiments, the opening may have an opening width Wo. Especially, in such embodiments, the opening may be at least 1 mm, such as at least 2 mm, like at least 5 mm. Further, in such embodiments, the opening width Wo may be at most 50 mm, like at most 25 mm, especially at most 15 mm. In specific embodiments, the opening width Wo may be larger than a diameter of the focal point of the light received by the movable support.

[0050] Alternatively, in embodiments, the movable support may comprise a phosphor track comprising luminescent material and a reflector. Especially, in such embodiments, the reflector may be configured as a layer on top of the movable support. In such embodiments, the support may be configured to reflect (blue) device light received by the reflector. More especially, in embodiments, at least part of the (blue) device light received by the movable support may be reflected by the reflector to the stationary support. In such embodiments, at least 5% of the (blue) device light received by the movable support may be reflected to the stationary support, such as at least 10%, like at least 30%, especially at least 30%. Further, in such embodiments, at most 95% of the (blue) device light received by the movable support may be reflected to the stationary support, such as at most 90%, like at most 80%, especially at most 70%. Hence, in embodiments, the movable support comprises a phosphor track comprising the second luminescent material and (i) an opening configured to transmit (blue) device light received by the opening to the stationary support, or (ii) a reflector configured to reflect (blue) device light received by the reflector to the stationary support.

[0051] As indicated above, in embodiments, (i) the first support may comprise a static support configured to support the first luminescent material and configured in thermal contact with (or comprising) a thermally conductive element, and (ii) the second support may comprise a movable support configured to support the second luminescent material. In other words, a static relatively small (see also further below) green-yellow garnet phosphor tile can be applied on a heatsink (e.g. comprising a vapor chamber) and a red phosphor (i.e. a red light-emitting phosphor) can be applied on a phosphor wheel or rod. In this way, heating of the red phosphor by the green-yellow garnet phosphor may be prevented and a warm-white (i.e. low CCT e.g. 2500-3500 K) high-intensity light source with a high CRI (e.g. 85+) may be obtained.

[0052] Hence, the light generating system as described herein may, in embodiments, be configured to generate system light. Especially, in embodiments, the light generating system may be configured such that in a first operational mode of the light generating system the system light may comprise (one or more of) at least part of the device light, at least part of the first luminescent material light, and at least part of the second luminescent material light. In specific embodiments, in an operational mode of the light generating system, the system light may comprise (i) part of the (blue) device light, (ii) the (green-yellow) first luminescent material light, and (iii) the (red) second luminescent material light. In such embodiments, the system light may (thus) be white light. Hence, in embodiments, the light generating system may be configured to generate white system light (in an operational mode). Especially, in embodiments, the light generating system may be configured to generate white system light having a correlated color temperature selected from the range of 1500-10000 K and a color rendering index of at least 65. Moreover, in embodiments, the system light in the first operational mode may have a correlated color temperature selected from the range of 1000-10000 K, such as from the range of 1500-8000 K, like from the range of 1500-3500 K (i.e., warm-white light). Additionally or alternatively, in embodiments, the system light in the first operational mode may have a color rendering index of at least 75, such as at least 80, like at least 85 especially at least 90.

[0053] The term “white light”, and similar terms, herein, is known to the person skilled in the art. It may especially relate to light having a correlated color temperature (CCT) between about 1500 K and 20000 K, such as between 1800 K and 20000 K, such as between 2000 and 20000 K, especially 2700-20000 K. For general lighting the term “white light” may especially relate to light having a correlated color temperature (CCT) in the range of about 2000-7000 K, such as in the range of 2700 K and 6500 K. In embodiments, e.g. for backlighting purposes, or for other purposes, the correlated color temperature (CCT) may especially be in the range of about 7000 K and 20000 K. Yet further, in embodiments the correlated color temperature (CCT) is especially within about 15 SDCM (standard deviation of color matching) from the BBL (black body locus), especially within about 10 SDCM from the BBL, even more especially within about 5 SDCM from the BBL.

[0054] In specific embodiments, the correlated color temperature (CCT) may be selected from the range of 6000-12000 K, like selected from the range of 7000-12000 K, like at least 8000 K. Yet further, in embodiments the correlated color temperature (CCT) may be selected from the range of 6000-12000 K, like selected from the range of 7000-12000 K, in combination with a color rendering index (CRI) of at least 70. Especially, in embodiments, the CRI may be at least 65, such as at least 68, like at least 70. In specific embodiments, the CRI may be at least 75, such as at least 80, including at least 90.

[0055] The terms “visible”, “visible light” or “visible emission” and similar terms refer to light having one or more wavelengths in the range of about 380-780 nm. Herein, UV may especially refer to a wavelength selected from the range of 190-380 nm, such as 200-380 nm. Herein, IR (infrared) may especially refer to radiation having a wavelength selected from the range of 780-3000 nm, such as 780-2000 nm, e.g. a wavelength up to about 1500 nm, like a wavelength of at least 900 nm, though in specific embodiments other wavelengths may also be possible. The terms “light” and “radiation” are herein interchangeably used, unless clear from the context that the term “light” only refers to visible light. The terms “light” and “radiation” may thus refer to UV radiation, visible light, and IR radiation. In specific embodiments, especially for lighting applications, the terms “light” and “radiation” refer to (at least) visible light. The terms “violet light” or “violet emission” especially relates to light having a wavelength in the range of about 380-440 nm. The terms “blue light” or “blue emission” especially relates to light having a wavelength in the range of about 440-495 nm (including some violet and cyan hues). The terms “green light” or “green emission” especially relate to light having a wavelength in the range of about 495-570 nm. The terms “yellow light” or “yellow emission” especially relate to light having a wavelength in the range of about 570-590 nm. The terms “orange light” or “orange emission” especially relate to light having a wavelength in the range of about 590-620 nm. The terms “red light” or “red emission” especially relate to light having a wavelength in the range of about 620-780 nm. The phrase “light having one or more wavelengths in a wavelength range” and similar phrases may especially indicate that the indicated light (or radiation) has a spectral power distribution with at least intensity or intensities at these one or more wavelengths in the indicate wavelength range. For instance, a blue emitting solid state light source will have a spectral power distribution with intensities at one or more wavelengths in the 440-495 nm wavelength range.

[0056] Here below, some general aspects in relation to luminescent materials are described, which may apply to both the first luminescent material and the second luminescent material, but also to other (optional) luminescent materials (if any).

[0057] The luminescent material is configured to convert at least part of (blue) light (or a first radiation e.g. selected from one or more of UV radiation and visible radiation), into luminescent material light. Especially, in embodiments the luminescent material may be configured to convert at least part of blue light (as radiation) into luminescent material light. Especially when blue light is partly converted, the blue light may be used as source of blue light (for the device light) and as excitation light that can be converted by the luminescent material. The first radiation may especially be provided by a (solid state) light source.

[0058] Hence, the term “luminescent material” especially refers to a material that can convert first radiati on, (especially one or more of UV radiation and blue radiation,) into second radiation. In general, the first radiation and second radiation have different spectral power distributions. Hence, instead of the term “luminescent material”, also the terms “luminescent converter” or “converter” may be applied. Further, instead of the term “luminescent material” also the term “phosphor” may be applied. These terms are known to the person skilled in the art. In general, the second radiation has a spectral power distribution at larger wavelengths than the first radiation, which is the case in the so-called downconversion. In specific embodiments, however the second radiation has a spectral power distribution with intensity at smaller wavelengths than the first radiation, which is the case in the so-called up-conversion. In embodiments, the “luminescent material” may especially refer to a material that can convert radiation into e.g. visible and / or infrared light. For instance, in embodiments the luminescent material may be able to convert one or more of UV radiation and blue radiation, into visible light. In general, the luminescent material will be a down converter, i.e. radiation of a smaller wavelength is converted into radiation with a larger wavelength ( ex< em), though in specific embodiments the luminescent material may comprise up- converter luminescent material, i.e. radiation of a larger wavelength is converted into radiation with a smaller wavelength ( x> m).

[0059] In embodiments, the term “luminescence” may refer to phosphorescence. In embodiments, the term “luminescence” may also refer to fluorescence. Instead of the term “luminescence”, also the term “emission” may be applied. Hence, the terms “first radiation” and “second radiation” may refer to excitation radiation and emission (radiation), respectively. Likewise, the term “luminescent material” may in embodiments refer to phosphorescence and / or fluorescence.

[0060] The term “luminescent material” may also refer to a plurality of different luminescent materials. Examples of possible luminescent materials are indicated below. Hence, the term “luminescent material” may in specific embodiments also refer to a luminescent material composition. The term “luminescent material” herein may also refer to a material comprising a luminescent material, such as a light transmissive host comprising the luminescent material. In specific embodiments, the first luminescent material may comprise a different luminescent material composition than the second luminescent material.

[0061] When different luminescent materials are applied, one or more luminescent materials may be configured to convert incident light into one or more of green and yellow luminescent material light, and one or more other luminescent materials may be configured to convert incident light into one or more of orange and red luminescent material light.

[0062] In embodiments, luminescent materials are selected from garnets and nitrides, especially doped with trivalent cerium or divalent europium, respectively. The term “nitride” may also refer to oxynitride or nitridosilicate, etc. Alternatively or additionally, the luminescent material(s) may be selected from silicates, especially doped with divalent europium.

[0063] Alternatively or additionally, the luminescent material may comprise a luminescent material of the type AsSieNiuCe3, wherein A comprises one or more of Y, La, Gd, Tb and Lu, such as in embodiments one or more of La and Y. The garnet type luminescent material may also be described with an alternative formula AsB^C’^On. Here, A may comprise one or more of (i) rare earth ions, such as one or more selected from Y3+, Lu3+, Gd3+, Tb3+, La3+, and (ii) divalent cations, such as Ca2+. Here, B may comprise one or more of (i) trivalent cations, such as one or more of Al3+, Ga3+, Sc3+, Sb3+, and In3+, and (ii) divalent cations, such as one or more of Mg2+and Mn2+. Here, C may comprise one or more of (i) trivalent cations, such as one or more of Ga3+and Al3+, (ii) divalent cations, such as Mn2+, and (iii) tetravalent cations, such as one or more of Si4+and Ge4+. With such ions, the garnet crystal structure can be maintained. Other substitutions than mentioned may also be possible.

[0064] In embodiments, the luminescent material may alternatively or additionally comprise one or more of MS:Eu2+and / or LSisNs Eu2and / or MAlSiNs Eu2and / or Ca2AlSi3O2Ns:Eu2+, etc., wherein M comprises one or more of Ba, Sr and Ca, especially in embodiments at least Sr. Hence, in embodiments, the luminescent material may comprise one or more materials selected from the group consisting of (Ba,Sr,Ca)S:Eu, (Ba,Sr,Ca)AlSiN3:Eu and (Ba,Sr,Ca)2SisN8:Eu. In these compounds, europium (Eu) is substantially or only divalent, and replaces one or more of the indicated divalent cations. In general, Eu will not be present in amounts larger than 10% of the cation; its presence will especially be in the range of about 0.5 to 10%, more especially in the range of about 0.5 to 5% relative to the cation(s) it replaces. The term “:Eu”, indicates that part of the metal ions is replaced by Eu (in these examples by Eu2+). For instance, assuming 2% Eu in CaAlSi Eu, the correct formula could be (Cao.98Euo.o2)AlSiN3. Divalent europium will in general replace divalent cations, such as the above divalent alkaline earth cations, especially Ca, Sr or Ba. The material (Ba,Sr,Ca)S:Eu can also be indicated as MS:Eu, wherein M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca); especially, M comprises in this compound calcium or strontium, or calcium and strontium, more especially calcium. Here, Eu is introduced and replaces at least part of M (i.e. one or more of Ba, Sr, and Ca). Further, the material (Ba,Sr,Ca)2SisN8:Eu can also be indicated as NESis Eu, wherein M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca); especially, M comprises in this compound Sr and / or Ba. In a further specific embodiment, M consists of Sr and / or Ba (not taking into account the presence of Eu), especially 50 to 100%, more especially 50 to 90% Ba and 50 to 0%, especially 50 to 10% Sr, such as Bai.sSro.sSis Eu (i.e. 75 % Ba; 25% Sr). Here, Eu is introduced and replaces at least part of M, i.e. one or more of Ba, Sr, and Ca). Likewise, the material (Ba,Sr,Ca)AlSiN3:Eu can also be indicated as MAlSi Eu, wherein M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca); especially, M comprises in this compound calcium or strontium, or calcium and strontium, more especially calcium. Here, Eu is introduced and replaces at least part of M (i.e. one or more of Ba, Sr, and Ca). Eu in the above indicated luminescent materials is substantially or only in the divalent state, as is known to the person skilled in the art. Hence, such nitride luminescent materials may also be or comprise converter elements, here especially Eu2+.

[0065] Especially, the luminescent material may be an inorganic luminescent material, such as one or more of the above-described trivalent cerium or divalent europium comprising oxides, oxynitrides, or nitrides.

[0066] Different luminescent materials may have different spectral power distributions of the respective luminescent material light. Alternatively or additionally, such different luminescent materials may especially have different color points (or dominant wavelengths).

[0067] As described above, in embodiments, the first luminescent material may especially comprise a luminescent material configured to convert device light received by the first luminescent material into green-yellow first luminescent material light. Conversely, in embodiments, the second luminescent material may especially comprise a luminescent material configured to convert device light received by the second luminescent material into (orange-)red first luminescent material light. Hence, in embodiments, the second luminescent material may comprise a red luminescent material.

[0068] In embodiments, a red luminescent material may comprise one or more materials selected from the group consisting of (Ba,Sr,Ca)S:Eu, (Ba,Sr,Ca)AlSiN3:Eu and (Ba,Sr,Ca)2SisN8:Eu. In these compounds, europium (Eu) is substantially or only divalent, and replaces one or more of the indicated divalent cations. In general, Eu will not be present in amounts larger than 10% of the cation; its presence will especially be in the range of about 0.5 to 10%, more especially in the range of about 0.5 to 5% relative to the cation(s) it replaces. The term “:Eu”, indicates that part of the metal ions is replaced by Eu (in these examples by Eu2+). For instance, assuming 2% Eu in CaAlSi Eu, the correct formula could be (Cao.98Euo.o2)AlSiN3. Divalent europium will in general replace divalent cations, such as the above divalent alkaline earth cations, especially Ca, Sr or Ba.

[0069] The material (Ba,Sr,Ca)S:Eu can also be indicated as MS:Eu, wherein M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca); especially, M comprises in this compound calcium or strontium, or calcium and strontium, more especially calcium. Here, Eu is introduced and replaces at least part of M (i.e. one or more of Ba, Sr, and Ca).

[0070] Further, the material (Ba,Sr,Ca)2SisN8:Eu can also be indicated as NfcSis Eu, wherein M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca); especially, M comprises in this compound Sr and / or Ba. In a further specific embodiment, M consists of Sr and / or Ba (not taking into account the presence of Eu), especially 50 to 100%, more especially 50 to 90% Ba and 50 to 0%, especially 50 to 10% Sr, such as Bai.sSro.sSisNsHu (i.e. 75 % Ba; 25% Sr). Here, Eu is introduced and replaces at least part of M, i.e. one or more of Ba, Sr, and Ca).

[0071] Likewise, the material (Ba,Sr,Ca)AlSiN3:Eu can also be indicated as MAlSi Eu, wherein M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca); especially, M comprises in this compound calcium or strontium, or calcium and strontium, more especially calcium. Here, Eu is introduced and replaces at least part of M (i.e. one or more of Ba, Sr, and Ca).

[0072] Eu in the above indicated luminescent materials is substantially or only in the divalent state, as is known to the person skilled in the art.

[0073] Hence, in embodiments, the second luminescent material may comprise (Ba,Sr,Ca)AlSiN3:Eu. Additionally or alternatively, in embodiments, the second luminescent material may comprise (Ba,Sr,Ca)2SisN8:Eu. Additionally or alternatively, in embodiments, the second luminescent material may comprise Sie-zAlzOzNs-z r, wherein 0 < z < 2.0. Additionally or alternatively, in embodiments, the second luminescent material may comprise (Sri-xEux)aSipAl705N<o, wherein 0 < x <1, 0 < a < 3, 5 < P < 7, 3 < y < 5, 0.5 < 5 < 0.8, and 5 < co < 15. Especially, in embodiments, the second luminescent material may comprise (Sri- xEux)aSipAlYO5Nra, wherein 0.001 < x <0.5, such as 0.005 < x <0.1.

[0074] Furthermore, in embodiments, the (red) second luminescent material may comprise a nitride and / or oxynitride phosphor. Especially, in specific embodiments, the second luminescent material may comprise one or more materials selected from the group consisting of (Ca,Sr,Ba,Eu)[Mg2AhN4]:Eu, (Ca,Sr)[Li2A13N4]:Eu, Ba[Mg2Ga2N4]:Eu, (Sr,Ba)[Mg3SiN4]:Eu, and CaMg2AlN3.

[0075] In embodiments, the (red) second luminescent material may especially comprise a silicate phosphor. Especially, in embodiments, the second luminescent material may comprise one or more materials selected from the group consisting of Eu doped halo oxides, sulfides, selenides, and Eu2+doped non-sulfide hosts. More especially, in embodiments, the second luminescent material may comprise one or more materials selected from the group consisting of Sr3SiOs:Eu2+, S^SisNs Eu2, CaAlSiNs, Cai-xSrxS:Eu2+(wherein 0 < x <1, such as 0.001 < x <0.5), SrY2S4:Eu2+, and (Li,Na,K)(Ca,Sr,Ba)PO4:Eu2+. In embodiments, the material (Li,Na,K)(Ca,Sr,Ba)PO4:Eu2+can also be indicated as ABPO4:EU2+, wherein A is one or more elements selected from the group consisting of lithium (Li), sodium (Na), and potassium (K), and wherein B is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca). Especially, in embodiments, B comprises in this compound calcium or strontium, or calcium and strontium, more especially calcium.

[0076] The (red) second luminescent material may, as indicated above, also comprise Eu2+-doped non-sulfide hosts. Especially, in embodiments, the second luminescent material may comprise one or more of the nitridosilicates (Eu,Ba,Sr,Ca)2SisN8, Eu2+-doped Ba2SisNs, S^SisNs, and Ca2SisN8.

[0077] Another class of red phosphors may be based on Ce3+- doped hosts. Hence, in embodiments, the second luminescent material may comprise Ce3+-doped hosts, such as e.g. CaSiN2, Lu2CaMg2(Si,Ge)30i2, and CaSiN2.

[0078] Further, in embodiments, a (red) luminescent material may comprise a luminescent material of the type M’xM2-2XAXe doped with tetravalent manganese, wherein M’ comprises an alkaline earth cation, M comprises an alkaline cation, and x may be selected from the range of 0-1, wherein A comprises a tetravalent cation, for instance comprising one or more of silicon and titanium, wherein X comprises a monovalent anion, at least comprising fluorine. A luminescent material of the type M’xM2-2XAXe doped with tetravalent manganese may herein also be indicated as “KSiF” or “KSF”, whether or not M comprises K or one or more other alkaline cations. A luminescent material of the type M’xM2-2XAXe doped with tetravalent manganese is amongst others described in WO2013121355A1, which is herein incorporated by reference. Passages from WO2013121355A1 are also copied herein. Relevant alkaline earth cations (M’) are magnesium (Mg), strontium (Sr), calcium (Ca) and barium (Ba), especially one or more of Sr and Ba. Relevant alkaline cations (M) are sodium (Na), potassium (K) and rubidium (Rb). Optionally, also ammonium (NH4+), lithium (Li) and / or cesium (Cs) may be applied. In a preferred embodiment, M comprises at least potassium. In yet another embodiment, M comprises at least rubidium. In another preferred embodiment, M comprises at least potassium and rubidium. In an embodiment, preferably at least 80% (i.e. 80% of all moles of the type M), even more preferably at least 90%, such as 95% of M consists of potassium and / or rubidium. Optionally, the M’xM2-2XAXe luminescent material has the hexagonal phase. In yet another embodiment, the M’xM2-2XAXe luminescent material has the cubic phase. In an embodiment, a combination of different alkaline cations may be applied. In yet another embodiment, a combination of different alkaline earth cations may be applied. In yet another embodiment, a combination of one or more alkaline cations and one or more alkaline earth cations may be applied. For instance, KRbo.sSro^sAXe might be applied, wherein x may be selected from the range of 0-1, especially x < 1. In specific embodiments, x = 0.

[0079] The term “tetravalent manganese” refers to Mn4+. This is a well-known luminescent ion. In the formula as indicated above, part of the tetravalent cation A (such as Si) is being replaced by manganese. Hence, M’xM2-2xAX6 doped with tetravalent manganese may also be indicated as M’xM2-2xAi-mMnmX6. The mole percentage of manganese, i.e. the percentage it replaces the tetravalent cation A will in general be in the range of 0.1-15 %, especially 1-12 %, i.e. m is in the range of 0.001-0.15, especially in the range of 0.01-0.12. As manganese replaces part of a host lattice ion and has a specific function, it is also indicated as “dopant” or “activator”. Hence, the hexafluorosilicate is doped or activated with manganese (Mn4+).

[0080] In embodiments, A comprises a tetravalent cation, and preferably at least comprises silicon. A may optionally (further) comprise one or more of titanium (Ti), germanium (Ge), stannum (Sn) and zinc (Zn). Preferably, at least 80%, even more preferably at least 90%, such as at least 95% of A consists of silicon.

[0081] As indicated above, X relates to a monovalent anion, but at least comprises fluorine. Other monovalent anions that may optionally be present may be selected from the group consisting of chlorine (Cl), bromine (Br), and iodine (I). Preferably, at least 80%, even more preferably at least 90%, such as 95% of X consists of fluorine. Especially, X may essentially consist of F (fluorine).

[0082] In an embodiment, M’xM2-2xAX6 comprises BGSiFe (indicated herein also as KSiF system). In another preferred embodiment, M’xM2-2xAX6 comprises KRbSiFe (herein also indicated as K,Rb system). In specific embodiments, the indication M’xM2-2xAX6 may refer to one or more of (K,Rb)2SiFe:Mn4+, (K,Rb)2TiFe:Mn4+, K2(Si,Ti)Fe:Mn4+, and Rb2(Si,Ti)Fe:Mn4+, such as one or more of K2TiFe:Mn4+, of K2SiFe:Mn4+, and of Rb2SiFe:Mn4+. In embodiments, a luminescent material may comprise (K,Rb)2SiFe:Mn4+. Additionally or alternatively, in embodiments, a luminescent material may comprise K2(Si,Ti)Fe:Mn4+. In specific embodiments, a luminescent material may especially comprise K2SiFe:Mn4+. As can be derived from the above, “(Si,Ti)” may indicate one or more of Si and Ti (and “(K,Rb)” may indicate one or more of K and Rb). Hence, in specific embodiments, a luminescent material may comprise one or more of (K,Rb)2SiFe:Mn4+and K2(Si,Ti)Fe:Mn4+. The luminescent material may also be coated, as also described in WO2013121355A1.

[0083] Hence, in embodiments, the second luminescent material may comprise M’ZM2-2ZAX6 doped with tetravalent manganese. In such embodiments, M’ may comprise an alkaline earth cation. Furthermore, in such embodiments, M may comprise an alkaline cation, and z may be in the range from 0 to 1. Yet further, in such embodiments, A may comprise a tetravalent cation. Moreover, in such embodiments, X may comprise a monovalent anion, at least comprising fluorine.

[0084] As indicated above, other luminescent materials may also be possible. Hence, in specific embodiments the luminescent material is selected from the group of divalent europium containing nitrides, divalent europium containing oxynitrides, divalent europium containing silicates, cerium comprising garnets, and quantum structures. Quantum structures may e.g. comprise quantum dots or quantum rods (or other quantum type particles) (see above). Quantum structures may also comprise quantum wells. Quantum structures may also comprise photonic crystals.

[0085] The luminescent material may be comprised by a luminescent body. The luminescent body may be a layer, like a self-supporting layer. The luminescent body may also be a coating. The luminescent body may also comprise a luminescent coating on a support (especially a light transmissive support in the transmissive mode). Especially, the luminescent body may essentially be self-supporting. In embodiments, the luminescent material may be provided as luminescent body, such as a luminescent single crystal, a luminescent glass, or a luminescent ceramic body. Such body may be indicated as “converter body” or “luminescent body”. In embodiments, the luminescent body may be a luminescent single crystal or a luminescent ceramic body. For instance, in embodiments a cerium comprising garnet luminescent material may be provided as a luminescent single crystal or as a luminescent ceramic body. In other embodiments, the luminescent body may comprise a light transmissive body, wherein the luminescent material is embedded. For instance, the luminescent body may comprise a glass body, with luminescent material embedded therein. Or, the glass as such may be luminescent. In other embodiments, the luminescent body may comprise a polymeric body, with luminescent material embedded therein.

[0086] In embodiments, the first luminescent material may thus be comprised by a (first) luminescent body. In specific embodiments, the first luminescent material may have a first cross-sectional area Al. In embodiments, the first cross-sectional area Al may be defined in a plane perpendicular to an optical axis of light received by the first luminescent material. Similarly, in embodiments, the second luminescent material may thus be comprised by a (second) luminescent body. In specific embodiments, the second luminescent material may have a second cross-sectional area A2. In embodiments, the second cross-sectional area A2 may be defined in a plane perpendicular to an optical axis of light received by the second luminescent material. The (first and / or second) luminescent material may (each individually) have a rectangular or circular cross-section, though other cross-sections may also be possible, like e.g. hexagonal, octagonal, etc. Hence, the (first and / or second) luminescent material may have a circular cross-section, an oval cross-section, square, or non-square rectangular. In embodiments, the first luminescent material may have a relatively small first cross-sectional area Al relative to the second cross-sectional area A2 of the second luminescent material. In other words, the first luminescent material may be relatively small and the second luminescent material may be relatively larger compared to each other. Especially, in embodiments, A2 / A1>1, such as A2 / A1>2, like A2 / A1>5, especially A2 / Al>10. Alternatively, in embodiments, Al / A2>2, such as Al / A2>3. In specific embodiments, A2 / A1>2. Yet, in embodiments, A2 / Al<20, such as A2 / A1<15, like A2 / A1<12.

[0087] Further, in embodiments, the first luminescent material may be configured (or operated) in the reflective mode. Alternatively, in embodiments, the first luminescent material may be configured in the transmissive mode. In the transmissive mode, it may be relatively easy to have light source light admixed in the luminescent material light, which may be useful for generating the desirable spectral power distribution. In the reflective mode, thermal management may be easier, as a substantial part of the luminescent material may be in thermal contact with a thermally conductive element, like a heatsink or heat spreader (see further also below). Similarly to the first luminescent material, in embodiments, the second luminescent material may be configured (or operated) in the reflective mode. Alternatively, in embodiments, the second luminescent material may be configured in the transmissive mode. Hence, in some embodiments, one of the first luminescent material and the second luminescent material may be configured in the transmissive mode, and the other one of the first luminescent material and the second luminescent material may be configured in the reflective mode. Alternatively, in embodiments, both of the first luminescent material and the second luminescent material may be configured in the reflective (or transmissive) mode. Hence, in embodiments, the first luminescent material and / or the second luminescent material may be configured in the reflective mode. Hence, in (other) embodiments, the first luminescent material and / or the second luminescent material may be configured in the transmissive mode. In specific embodiments, the second luminescent material may be configured in the transmissive mode and the first luminescent material may be configured in the transmissive or reflective mode.

[0088] As indicated above, in embodiments, the (first and / or second) luminescent materials may be configured in thermal contact with a thermally conductive element.

[0089] An element may be considered in “thermal contact” with another element if it can exchange energy through the process of heat. Hence, the elements may be thermally coupled. In embodiments, thermal contact can be achieved by physical contact. In embodiments, thermal contact may be achieved via a thermally conductive material, such as a thermally conductive glue (or thermally conductive adhesive). Thermal contact may also be achieved between two elements when the two elements are arranged relative to each other at a distance of equal to or less than about 10 pm, though larger distances, such as up to 100 pm may be possible. The shorter the distance, the better the thermal contact. Especially, the distance is 10 pm or less, such as 5 pm or less, such as 1 pm or less. The distance may be the distance between two respective surfaces of the respective elements. The distance may be an average distance. When the two elements are configured at a distance from each other, an intermediate material may be configured in between, though in other embodiments, the distance between the two elements may filled with a gas, liquid, or may be vacuum. When an intermediate material is available, the larger the distance, the higher the thermal conductivity may be useful for thermal contact between the two elements. However, the smaller the distance, the lower the thermal conductivity of the intermediate material may be (of course, higher thermal conductive materials may also be used). Hence, in embodiments the luminescent material(s) may be configured in thermal contact with a thermally conductive material. For instance, the luminescent material(s) may be configured in thermal contact with a thermally conductive element(s).

[0090] Especially, in embodiments, the first support may comprise a thermally conductive element, configured to support the first luminescent material. Hence, in such embodiments, the first luminescent material may be configured in thermal contact with the thermally conductive element of the first support. Similarly, in embodiments, the second support may comprise a thermally conductive element, configured to support the second luminescent material. Hence, in such embodiments, the second luminescent material may be configured in thermal contact with the thermally conductive element of the second support. In specific embodiments, the luminescent material may be in the form of a powder or a ceramic plate. When the luminescent material is in the form of a ceramic plate, in embodiments, it may be provided with a reflective layer which may be soldered to a thermally conductive element, such as a heatsink.

[0091] A thermally conductive element may especially comprise thermally conductive material. A thermally conductive material may especially have a thermal conductivity of at least about 20 W / (m*K), like at least about 30 W / (m*K), such as at least about 100 W / (m*K), like especially at least about 200 W / (m*K). In yet further specific embodiments, a thermally conductive material may especially have a thermal conductivity of at least about 10 W / (m*K), such as e.g. one or more of copper, aluminum, silver, gold, silicon carbide, aluminum nitride, boron nitride, a carbide (composite), beryllium oxide, , a copper tungsten alloy, carbon, diamond, and graphite. Alternatively, or additionally, the thermally conductive material may comprise or consist of aluminum oxide. In embodiments, the thermally conductive element may comprise one or more of a heatsink, a heat spreader, and a two-phase cooling device (such as e.g. a vapor chamber). In yet other embodiments, the thermally conductive element may be configured in thermal contact with one or more of a heatsink, a heat spreader, and a two-phase cooling device, and may e.g. transfer heat to such heatsink, heat spreader, or two-phase cooling device, via another thermally conductive element.

[0092] As indicated above, the light generating system comprises a light generating device. A light generating device may especially be configured to generate device light. Especially, the light generating device may comprise a light source. The light source may especially configured to generate light source light. In embodiments, the device light may essentially consist of the device light. In other embodiments, the device light may essentially consist of converted light source light. In yet other embodiments, the device light may comprise (unconverted) light source light and converted light source light. Light source light may be converted with a luminescent material into luminescent material light and / or with an upconverter into upconverted light (see also below). The term “light generating device” may also refer to a plurality of light generating devices which may provide device light having essentially the same spectral power distributions. In specific embodiments, the term “light generating device” may also refer to a plurality of light generating devices which may provide device light having different spectral power distributions.

[0093] The term “light source” may in principle relate to any light source known in the art. The term “light source” may also relate to a plurality of (essentially identical (or different)) light sources, such as 2-2000 solid state light sources. In embodiments, the light source may comprise one or more micro-optical elements (array of micro lenses) downstream of a single solid-state light source, such as an LED, or downstream of a plurality of solid- state light sources (i.e. e.g. shared by multiple LEDs). In embodiments, the light source may comprise an LED with on-chip optics.

[0094] In a specific embodiment, the light source comprises a solid state LED light source (such as an LED or laser diode (or “diode laser”)).

[0095] The light source may have a light escape surface. For LED’s it may for instance be the LED die, or when a resin is applied to the LED die, the outer surface of the resin. In principle, it may also be the terminal end of a fiber. The term escape surface especially relates to that part of the light source, where the light actually leaves or escapes from the light source. The light source is configured to provide a beam of light. This beam of light (thus) escapes from the light exit surface of the light source. Likewise, a light generating device may comprise a light escape surface, such as an end window. Further, likewise a light generating system may comprise a light escape surface, such as an end window. A position where system light escapes from the light generating system may also be indicated as light exit. This may be a light transmissive window or an opening (in the system). The light transmissive window may in embodiments be provided by an optical component.

[0096] The light source may especially be configured to generate light source light having an optical axis (O), (a beam shape,) and a spectral power distribution. The light source light may in embodiments comprise one or more bands, e.g. having band widths as known for lasers.

[0097] The term “light source” may (thus) refer to a light generating element as such, like e.g. a solid state light source, or e.g. to a package of the light generating element, such as a solid state light source, and one or more of a luminescent material comprising element and (other) optics, like a lens, a collimator. A light converter element (“converter element” or “converter”) may comprise a luminescent material comprising element. For instance, a combination of a solid state light source (as light generating element) and a light converter element, such as a blue LED and a light converter element, optically coupled to the solid state light source, may also be a light source (but may also be indicated as light generating device). Hence, a white LED is a light source (but may e.g. also be indicated as (white) light generating device).

[0098] The term “light source” herein may also refer to a light source comprising a solid state light source, such as an LED or a laser diode or a superluminescent diode. In embodiments, the term “light source” may also refer to a combination of a light source, like an LED, and an optical filter, which may change the spectral power distribution of the light generated by the light source. Especially, the term “light generating device” may be used to address a light source and further (optical components), like an optical filter and / or a beam shaping element, etc.

[0099] The phrases “different light sources” or “a plurality of different light sources”, and similar phrases, may in embodiments refer to a plurality of solid-state light sources selected from at least two different bins. Likewise, the phrases “identical light sources” or “a plurality of same light sources”, and similar phrases, may in embodiments refer to a plurality of solid-state light sources selected from the same bin.

[0100] The term “laser light source” especially refers to a laser. Such laser may especially be configured to generate laser light source light having one or more wavelengths in the UV, visible, or infrared, especially having a wavelength selected from the spectral wavelength range of 200-2000 nm, such as 300-1500 nm. The term “laser” especially refers to a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation.

[0101] Especially, in embodiments the term “laser” may refer to a solid-state laser. In specific embodiments, the terms “laser” or “laser light source”, or similar terms, refer to a laser diode (or diode laser).

[0102] In embodiments, the terms “laser” or “solid state laser” or “solid state material laser” may refer to one or more of a semiconductor laser diodes, such as GaN, InGaN, AlGalnP, AlGaAs, InGaAsP, lead salt, vertical cavity surface emitting laser (VCSEL), quantum cascade laser, hybrid silicon laser, etc.

[0103] As can be derived from the below, the term “laser light source” may also refer to a plurality of (different or identical) laser light sources. In specific embodiments, the term “laser light source” may refer to a plurality N of (identical) laser light sources. In embodiments, N=2, or more. In specific embodiments, N may be at least 5, such as especially at least 8. In this way, a higher brightness may be obtained. In embodiments, laser light sources may be arranged in a laser bank. The laser bank may in embodiments comprise heat sinking and / or optics e.g. a lens to collimate the laser light. Hence, in embodiments lasers in a laser bank (or “laser array bank”) may share the same optics.

[0104] The laser light source is configured to generate laser light source light (or “laser light”). The light source light may essentially consist of the laser light source light. The light source light may also comprise laser light source light of two or more (different or identical) laser light sources. For instance, the laser light source light of two or more (different or identical) laser light sources may be coupled into a light guide, to provide a single beam of light comprising the laser light source light of the two or more (different or identical) laser light sources. In specific embodiments, the light source light is thus especially focused or collimated (laser) light source light.

[0105] The laser light source light may in embodiments have a spectral power distribution (intensity on an energy scale as function of the wavelength) which may comprise one or more (narrow) bands, having band widths as known for lasers. In specific embodiments, the band(s) may be relatively sharp line(s), such as having full width half maximum (FWHM) in the range of less than 20 nm at RT, such as equal to or less than 10 nm. The term “focused” may especially refer to converging to a small spot. This small spot may be at a target region, or (slightly) upstream thereof or (slightly) downstream thereof. In embodiments, the beam of (laser) light source light may be relatively highly collimated, such as in embodiments <2° (FWHM), more especially <1° (FWHM), most especially <0.5° (FWHM). Hence, <2° (FWHM) may be considered (highly) collimated light source light. Optics may be used to provide (high) collimation (see also above).

[0106] The term “solid state material laser”, and similar terms, may refer to a solid state laser like based on a crystalline or glass body doped with ions, like transition metal ions and / or lanthanide ions, to a fiber laser, to a photonic crystal laser, to a semiconductor laser, such as e.g. a vertical cavity surface-emitting laser (VCSEL), etc.

[0107] The terms “solid state light source”, “semiconductor-based light source” and similar terms, may especially refer to semiconductor light sources, such as a light emitting diode (LED), a laser diode, or a superluminescent diode. Hence, the light generating device may comprise one or more of a light emitting diode (LED), a laser diode, and a superluminescent diode.

[0108] Superluminescent diodes are known in the art. A superluminescent diode may be indicated as a semiconductor device which may be able to emit low-coherence light of a broad spectrum like an LED, while having a brightness in the order of a laser diode. An SLD may especially be a semiconductor light source, where the spontaneous emission light is amplified by stimulated emission in the active region of the device. Such emission is called “super luminescence”. Superluminescent diodes combine the high power and brightness of laser diodes with the low coherence of conventional light-emitting diodes. The low (temporal) coherence of the source has advantages that the speckle is significantly reduced or not visible, and the spectral distribution of emission is much broader compared to laser diodes, which can be better suited for lighting applications. Hence, in embodiments, the solid state light source may comprise a superluminescent diode. For instance, in further specific embodiments, the solid state light source may comprise a GaN-based superluminescent diode, or an InGaN-based superluminescent diode, or an AlGaN-based superluminescent diode.

[0109] In embodiments, the one or more light generating devices may comprise a first light generating device configured to generate first device light. In specific embodiments, the first luminescent material may be configured in a light-receiving relationship with the first light generating device. Especially, in embodiments, the first luminescent material may be configured to convert at least part of the first device light received by the first luminescent material into first luminescent material light. In such embodiments, the first device light may comprise blue light, i.e., light having a wavelength selected from the wavelength range of 440-490 nm.

[0110] Further, in embodiments, the one or more light generating devices may comprise a second light generating device configured to generate second device light. In specific embodiments, the second luminescent material may be configured in a lightreceiving relationship with the second light generating device. Especially, in embodiments, the second luminescent material may be configured to convert at least part of the second device light received by the second luminescent material into second luminescent material light. In such embodiments, the second device light may comprise blue light, i.e., light having a wavelength selected from the wavelength range of 440-490 nm. The use of separate light generating devices, i.e. a first light generating device for pumping the first luminescent material and a second light generating device for pumping the second luminescent material, may provide the benefit of facile tuneability of the system light through individually controlling the light generating devices, see also further below.

[0111] In further embodiments, the one or more light generating devices may comprise a third light generating device configured to generate third device light. Especially, in embodiments, the third device light may comprise blue light, i.e., light having a wavelength selected from the wavelength range of 440-490 nm. The third light generating device may, in embodiments, especially be configured to provide a blue contribution to the system light.

[0112] In embodiments, the third device light may typically be diffused by a diffuser. Hence, in embodiments, a diffuser may be configured downstream of (i.e., in a lightreceiving relationship with) the third light generating device. The diffuser may be configured to diffuse and / or scatter the device light received by the diffuser. In specific embodiments, such a diffuser may be configured in the reflective mode, i.e., the diffuser may be configured to substantially diffuse and reflect the device light. In embodiments, the diffuser may be configured to diffuse at least part of the device light received by the diffuser element while maintaining at least part of the polarization of the device light. Hence, in such embodiments, the diffuser may be configured to provide diffused (third) device light, especially while maintaining at least part of the polarization of the device light. Further, in such embodiments, the diffuser may be configured in the reflective mode. Such embodiments may be beneficial as a reflective diffuser configuration may provide a relatively eye-safe way of including (blue) device light into the (whit output) system light.

[0113] In embodiments, the third device light may especially be linearly polarized light. As such, in embodiments, the light generating system may further comprise a polarizing beam splitter and a polarization changing element. In embodiments, the polarizing beam splitter may be configured downstream of the third light generating device and upstream of the polarization changing element and the diffuser. Especially, in embodiments, the polarizing beam splitter may be configured to transmit s-polarized light or p-polarized light, and the reflect p-polarized light or s-polarized light.

[0114] Further, in embodiments, the polarization changing element may be configured in an optical path of the device light between the polarizing beam splitter and the diffuser. Especially, in embodiments, the polarization changing element may comprise one or more of a X / 4 waveplate and a Faraday rotator (especially providing a quarter wave retardation upon a single pass of device light). In embodiments, the polarization changing element may be configured to change s-polarized light or p-polarized light to circular polarized light. The diffuser may change the direction of the polarized light (e.g. from right- handed to left-handed circular polarization or vice versa), but the circular polarized light may essentially stay circular polarized light. At least part of the diffused light, having circular polarization, will propagate from the diffuser to the polarization changing element, and then be converted to (diffused) s-polarized light and / or (diffused) p-polarized light, which may further propagate to the polarizing beam splitter. In this way, p-polarized light can be converted in diffused s-polarized light, and s-polarized light can be converted in diffused p- polarized light.

[0115] Especially, the polarization changing element may be an element that induces a 90° phase shift between the two orthogonal linear polarization components (s and p) of the light. The most common way is to use birefringent material (birefringent rotators), such as a quarter- wave plate. An alternative may be to use the Faraday effect, in which case the phase shift is caused by an applied magnetic field (Faraday rotators). Another alternative may be to use any component or set of components resulting in an up to 180° relative phase shift (after a double pass through the component, i.e., a pass of device light leaving the central optics towards the diffuser element and a pass of diffused device light leaving the diffuser element towards the central optics) of one polarization versus the other polarization. In embodiments, such phase shift may be the result of any one of birefringent, electro-optical, thermo-optical, magneto-optical or any other principle known in the art.

[0116] In alternative embodiments, the diffuser may also be configured in the transmissive mode, i.e., the diffuser may be configured to substantially diffuse and transmit the device light.

[0117] The light generating system may thus, in an operational mode, be configured to generate system light comprising one or more (such as all) of third device light, first luminescent material light, and second luminescent material light. In specific embodiments, in the first operational mode of the light generating system the system light may comprise (i) part of the (blue) third device light, (ii) (green-yellow) first luminescent material light, and (iii) (red-orange) second luminescent material light. Especially, in such specific embodiments, in the first operational mode of the light generating system the system light may comprise (i) part of the (blue) diffused (third) device light, (ii) (green-yellow) first luminescent material light, and (iii) (red-orange) second luminescent material light.

[0118] The different types may need to be combined into a same optical path to contribute to (or provide) the system light. Therefore, in embodiments, the light generating system may comprise one or more dichroic elements. Especially, in embodiments, the light generating system may comprise a first dichroic beam splitter. In embodiments, the first dichroic beam splitter may be configured between the first light generating device and the first luminescent material, i.e., may be configured in a light-receiving relationship with the first device light and the first luminescent material light (and optionally the third device light). Alternatively, in embodiments, (especially when the luminescent material is configured in the transmissive mode) the first dichroic beam splitter may be configured downstream of both the first light generating device and the first luminescent material (and optionally the third light generating device).

[0119] In embodiments, the first dichroic beam splitter may be configured to transmit at least part of the device light and reflect at least part of the first luminescent material light. Alternatively, in embodiments, the first dichroic beam splitter may be configured to reflect at least part of the device light and transmit at least part of the first luminescent material light. In specific embodiments, the first dichroic beam splitter may be configured to transmit at least part of the (first and optionally third) device light and reflect at least part of the first luminescent material light. In embodiments, the (first and second) dichroic beam splitter may especially be configured in a light-receiving relationship, such that the beam of light incident on the dichroic beam splitter has an angle of about 45° relative to a main surface of the dichroic beam splitter.

[0120] Moreover, in embodiments, the light generating system may comprise a second dichroic beam splitter. In embodiments, the second dichroic beam splitter may be configured between the second light generating device and the second luminescent material, i.e., may be configured in a light-receiving relationship with the second device light and the second luminescent material light (and optionally the third device light). Alternatively, in embodiments, (especially when the luminescent material is configured in the transmissive mode) the second dichroic beam splitter may be configured downstream of both the second light generating device and the second luminescent material (and optionally the third light generating device).

[0121] In embodiments, the second dichroic beam splitter may be configured to transmit at least part of the device light and reflect at least part of the second luminescent material light. Alternatively, in embodiments, the second dichroic beam splitter may be configured to reflect at least part of the device light and transmit at least part of the second luminescent material light. In specific embodiments, the second dichroic beam splitter may be configured to transmit at least part of the (second and optionally third) device light, to reflect at least part of the second luminescent material light, and to transmit at least part of the first luminescent material light.

[0122] In other words, in embodiments, color separation elements (dichroics) may be disposed between the laser light sources (light generating devices) and the wavelength converting elements (luminescent materials) and configured to prevent converted light from being (returned to, i.e.,) incident on the laser light sources. Especially, in embodiments, a beam combiner based on one or more dichroic mirrors may be used to combine first luminescent material light and second luminescent material light and third (blue) device light.

[0123] Hence, in specific embodiments the light generating system may further comprise a dichroic element, configured to transmit or reflect the light and configured to reflect or transmit the luminescent material light. The dichroic element may be an embodiment of a color separation element, such as described in US7070300, which is herein incorporated by reference. Especially, the color separation element may be selected from the group of a dichroic mirror, a dichroic cube, and a diffractive optical element. Optionally, the color separation element maybe provided using a hologram. Especially, the dichroic element may be a dichroic mirror or reflector.

[0124] Hence, in a light generating system comprising a source of light, like a light generating device (e.g. comprising a solid state light source) that emits light having a first wavelength range along a first beam path, a wavelength converting element (i.e. luminescent material) may be configured in the first beam path. Such wavelength converting element may in embodiments be physically separated from the source of light. Further, such wavelength converting element may be configured to convert at least part of the light having a first wavelength range into light having a second wavelength range along a second beam path. Especially, in embodiments a color separation element, especially a dichroic element, may be disposed between the source of light and the wavelength converting element. In embodiments, the color separation element may be configured to prevent substantially all of the light having the second wavelength range from being incident on the source of light. Hence, such color separation element may in embodiments be configured to (a) transmit at least part of the light having the first wavelength range and reflect at least part of the light having the second wavelength range, or (b) reflect at least part of the light having the first wavelength range and transmit at least part of the light having the second wavelength range.

[0125] Hence, for the dichroic beam splitter may apply that for a first wavelength range, the wavelength averaged transmission may be higher, like at least 10% points higher, such as at least 20% points higher, or even at least 30 % points, than for a second wavelength range. Similarly, for a first wavelength range, the wavelength averaged reflection may be lower, like at least 10% points lower, such as at least 20% points lower, or even at least 30 % points, than for a second wavelength range. Especially, in embodiments, the dichroic beam splitter may be configured to direct at least 60% of the light of the first wavelength range to a first direction and at least 60% of the light of the second wavelength range to a second direction, wherein the directions may in embodiments have a mutual angle selected from the range 45-135°, such as about 90°. The percentage of the light may refer to a spectral power (e.g. in Watt).

[0126] In general, in embodiments, a dichroic beam splitter may be configured to split different types of light into separate directions. Especially, in embodiments, the dichroic beam splitter may be configured to split different types of light into orthogonal directions. Note that, in embodiments, the term “dichroic beam splitter” and similar terms may also refer to a dichroic beam combiner. In such embodiments, the dichroic beam splitter (or combiner) may especially be configured to combine different types of light (having different wavelengths) that irradiate the dichroic beam splitter from essentially orthogonal directions into a same optical path.

[0127] The light generating system may further comprise one or more (further) optical elements. Especially, in embodiments, the light generating system may comprise one or more of collimating optics, condensing optics, homogenizing optics, and integrating optics. The term “optics” may especially refer to (one or more) optical elements. Hence, the terms “optics” and “optical elements” may refer to the same items. The optics may include one or more of mirrors, reflectors, collimators, lenses, prisms, diffusers, phase plates, polarizers, diffractive elements, gratings, dichroics, arrays of one or more of the aforementioned, etc. Alternatively or additionally, the term “optics” may refer to a holographic element or a mixing rod. In embodiments, the optics may include one or more of beam expander optics and zoom lens optics. In embodiments, the optics may comprise an integrator, like a “Koehler integrator” (or “Kohler integrator”).

[0128] Furthermore, in embodiments, the light generating system may further comprise a control system. In embodiments, the control system may be configured to control a spectral power distribution of the system light. Especially, in embodiments, the control system may be configured to control the spectral power distribution of the system light by (individually) controlling the one or more light generating devices. Furthermore, in embodiments, the control system may be configured to control the correlated color temperature of the system light by (individually) controlling the one or more light generating devices. In some embodiments, the control system may especially be configured to individually control two or more of the first light generating device, the second light generating device, and optionally the third light generating device. The system may be configured to control one or more of the first light generating device, the second light generating device, and optionally the third light generating device, such that in a first operational mode the system light may have a first correlated color temperature (CCT1). Additionally or alternatively, in embodiments, the control system may be configured to control one or more of the first light generating device, the second light generating device, and optionally the third light generating device, such that in a second operational mode the system light may have a second correlated color temperature (CCT2). Especially, in embodiment, the control system may be configured to individually control the light generating devices, such that the CCT may be altered from CCT1 in the first operational mode to CCT2 in the second operational mode, and vice versa. Further, in embodiments, CCT2-CCTl>250 K, like CCT2-CCTl>500 K, such as CCT2-CCTl>750 K, like, CCT2- CCTl>1000 K. Especially, in embodiments, CCT2-CCTl>1500 K. Further, in embodiments, CCT2-CCT1 may be at most 5000K, such as at most 3000K, like at most 2500K. Yet further, in embodiments, the control system may be configured to control movement of the movable support, for example through controlling the movement (i.e. direction, speed, and or frequency) of the movable support directly, or by controlling the operation of an actuator configured to move the movable support.

[0129] The term “controlling” and similar terms especially refer at least to determining the behavior or supervising the running of an element. Hence, herein “controlling” and similar terms may e.g. refer to imposing behavior to the element such as e.g. measuring, displaying, actuating, opening, shifting, changing temperature, etc.. Beyond that, the term “controlling” and similar terms may additionally include monitoring. Hence, the term “controlling” and similar terms may include imposing behavior on an element and also imposing behavior on an element and monitoring the element. The controlling of the element can be done with a control system, which may also be indicated as “controller”. The control system and the element may thus at least temporarily, or permanently, functionally be coupled. The element may comprise the control system. Control can be done via wired and / or wireless control. The term “control system” may also refer to a plurality of different control systems, which especially are functionally coupled, and of which e.g. one control system may be a master control system and one or more others may be slave control systems. A control system may comprise or may be functionally coupled to a user interface.

[0130] The control system may also be configured to receive and execute instructions from a remote control. In embodiments, the control system may be controlled via an App on a device, such as a portable device, like a Smartphone or I-phone, a tablet, etc.. The device is thus not necessarily coupled to the lighting system, but may be (temporarily) functionally coupled to the lighting system.

[0131] Hence, in embodiments the control system may (also) be configured to be controlled by an App on a remote device. In such embodiments the control system of the lighting system may be a slave control system or control in a slave mode. For instance, the lighting system may be identifiable with a code, especially a unique code for the respective lighting system. The control system of the lighting system may be configured to be controlled by an external control system which has access to the lighting system on the basis of knowledge (input by a user interface of with an optical sensor (e.g. QR code reader) of the (unique) code. The lighting system may also comprise means for communicating with other systems or devices, such as on the basis of Bluetooth, Thread, WIFI, LiFi, ZigBee, BLE or WiMAX, or another wireless technology.

[0132] The system, or apparatus, or device may execute an action in a “mode” or “operation mode” or “mode of operation” or “operational mode”. The term “operational mode may also be indicated as “controlling mode”. Likewise, in a method an action or stage, or step may be executed in a “mode” or “operation mode” or “mode of operation” or “operational mode”. This does not exclude that the system, or apparatus, or device may also be adapted for providing another controlling mode, or a plurality of other controlling modes. Likewise, this may not exclude that before executing the mode and / or after executing the mode one or more other modes may be executed.

[0133] However, in embodiments a control system may be available, that is adapted to provide at least the controlling mode. Would other modes be available, the choice of such modes may especially be executed via a user interface, though other options, like executing a mode in dependence of a sensor signal or a (time) scheme, may also be possible. The operation mode may in embodiments also refer to a system, or apparatus, or device, that can only operate in a single operation mode (i.e. “on”, without further tunability).

[0134] Hence, in embodiments, the control system may control in dependence of one or more of an input signal of a user interface, a sensor signal (of a sensor), and a timer. The term “timer” may refer to a clock and / or a predetermined time scheme.

[0135] In specific embodiments, the control system may be configured to control the one or more light generating devices in dependence of a safety signal. For example, in embodiments, the control system may be configured to receive a device light (especially laser)-output signal and a converted-light signal. Especially, the control system may be configured to determine a safe-to-operate parameter based on the laser-output signal and the converted-light signal received by the control system. Subsequently, in embodiments, the control system may be configured to control the operation of the one or more light generating devices based on a comparison between the safe-to-operate parameter and at least one predefined threshold.

[0136] The light generating system may be part of or may be applied in e.g. office lighting systems, household application systems, shop lighting systems, home lighting systems, accent lighting systems, spot lighting systems, theater lighting systems, fiber-optics application systems, projection systems, self-lit display systems, pixelated display systems, segmented display systems, warning sign systems, medical lighting application systems, indicator sign systems, decorative lighting systems, portable systems, automotive applications, (outdoor) road lighting systems, urban lighting systems, green house lighting systems, horticulture lighting, digital projection, or LCD backlighting. The light generating system (or luminaire) may be part of or may be applied in e.g. optical communication systems or disinfection systems.

[0137] In yet a further aspect, the invention also provides a lamp or a luminaire comprising the light generating system as defined herein. The luminaire may further comprise a housing, optical elements, louvres, etc. etc... The lamp or luminaire may further comprise a housing enclosing the light generating system. The lamp or luminaire may comprise a light window in the housing or a housing opening, through which the system light may escape from the housing. In yet a further aspect, the invention also provides a projection device comprising the light generating system as defined herein. Especially, a projection device or “projector” or “image projector” may be an optical device that projects an image (or moving images) onto a surface, such as e.g. a projection screen. The projection device may include one or more light generating systems such as described herein. Hence, in an aspect the invention also provides a lighting device selected from the group of a lamp, a luminaire, a projector device, a disinfection device, a photochemical reactor, an automotive lighting device, and an optical wireless communication device, comprising the light generating system as defined herein. The lighting device may comprise a housing or a carrier, configured to house or support, one or more elements of the light generating system. For instance, in embodiments the lighting device may comprise a housing or a carrier, configured to house or support one or more of the one or more light generating devices, the first luminescent material, the second luminescent material, the first support, and the second support.

[0138] BRIEF DESCRIPTION OF THE DRAWINGS

[0139] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which:

[0140] Figs. 1-2 schematically depict some embodiments of the light generating system.

[0141] Fig. 3 schematically depicts a spectral power distribution of the device light 1001 provided by the light generating system 1000.

[0142] Fig.4 schematically depicts some applications of the light generating system in lighting devices. The schematic drawings are not necessarily to scale.

[0143] DETAILED DESCRIPTION OF THE EMBODIMENTS

[0144] Fig. 1 schematically depicts a light generating system 1000 of the invention comprising one or more light generating devices 100, a first luminescent material 210, a second luminescent material 220, a first support 810, and a second support 820.

[0145] In embodiments, the one or more light generating devices 100 may be configured to generate device light 101. Especially, the device light 101 may comprise violet and / or blue light. Therefore, in embodiments, the one or more light generating devices 100 may comprise one or more solid state light sources 10 selected from laser diodes and superluminescent diodes. Especially, in embodiments, the one or more light generating devices 100 may comprise a first light generating device 110 configured to generate first device light 111. Further, in embodiments, the one or more light generating devices 100 may comprise a second light generating device 120 configured to generate second device light 121.

[0146] In embodiments, the first luminescent material 210 may be configured downstream of at least one of the light generating devices 100. The first luminescent material 210 may especially be configured to convert at least part of the device light 101 received by the first luminescent material 210 into first luminescent material light 211. Therefore, in embodiments, the first luminescent material 210 may comprise a luminescent material of the type AsBsOn Ce. Especially, A may comprise one or more of Y, La, Gd, Tb and Lu. Further, in embodiments, B may comprise one or more of Al, Ga, In and Sc. Especially, the first luminescent material 210 may be configured to generate green-yellow first luminescent material light 211. In specific embodiments, as depicted in Fig. 1A, the first luminescent material 210 may be configured to convert at least part of the first device light 111 received by the first luminescent material 210 into first luminescent material light 211.

[0147] Similarly, in embodiments, the second luminescent material 220 may be configured downstream of at least one of the light generating devices 100. The second luminescent material 220 may especially be configured to convert at least part of the device light 101 received by the second luminescent material 220 into second luminescent material light 221. In embodiments, the second luminescent material light 221 may especially have a peak emission wavelength in the (orange-)red wavelength range. In specific embodiments, as depicted in Fig. 1 A, the second luminescent material 220 may be configured to convert at least part of the second device light 121 received by the second luminescent material 220 into second luminescent material light 221.

[0148] Furthermore, in embodiments, the first support 810 may be configured to support the first luminescent material 210. As depicted here, in embodiments, the first luminescent material 210 may be configured onto the first support 810. In alternative embodiments, the first luminescent material 210 may e.g. be configured embedded into the first support 810. Similarly, in embodiments, the second support 820 may be configured to support the second luminescent material 220.

[0149] In specific embodiments, the first support 810 may be a stationary support and the second support 820 may be a movable support. The movable support may, in embodiments, be comprised by a wheel-type support, a cylinder-type support, or a conveyorbelt type support, such as e.g. a phosphor wheel or a phosphor rod (see Fig. IB). However, in alternative embodiments, this may be the other way around, or even both supports may be movable supports. Here, in embodiments, the second support 820 may be configured to move (such as e.g. laterally or rotationally) during a first operational mode of the light generating system 1000. In specific embodiments, the second support 820 may be a rotatable support, i.e., the second support 820 may be configured to rotate during the first operational mode of the light generating system 1000

[0150] In embodiments, the light generating system 1000 may be configured to generate system light 1001. Especially, in embodiments, in a first operational mode of the light generating system 1000: the system light 1001 may comprise (one or more of) (i) part of the device light 101, (ii) first luminescent material light 211, and (iii) second luminescent material light 221. Hence, in embodiments, the light generating system 1000 may be configured to generate white light, though this may not necessarily be the case. Especially, in embodiments, the system light 1001 may have a correlated color temperature selected from the range of 1500-10000 K and a color rendering index of at least 65.

[0151] Moreover, as depicted in Fig. 1A, the first support 810 may comprise a thermally conductive element 815 configured to support (and provide thermal management to) the first luminescent material 210. Similarly, in embodiments (not depicted), the second support 820 may comprise a thermally conductive element 815 configured to support (and provide thermal management to) the second luminescent material 220. In embodiments, the thermally conductive element 815 may comprise one or more of a heat sink, a heat spreader, and a two-phase cooling device. In embodiments, the first and / or second supports 810,820 may be configured in thermal contact with the thermally conductive element 815. Alternatively, as depicted here, the first and / or second supports 810,820 may comprise, or essentially be, such a thermally conductive element 815, such as e.g. a heat spreader or heat sink.

[0152] Such thermal management may especially be relevant as, in embodiments as depicted here in Fig. 1 A, the first luminescent material 210 and( / or) the second luminescent material 210 may be configured in the reflective mode. Conversely, in alternative embodiments (not depicted), the first luminescent material 210 and / or the second luminescent material 210 may be configured in the transmissive mode.

[0153] To combine the different types of light into the system light 1001, the light generating system may comprise optical elements. Especially, in embodiments, the light generating system may comprise a first dichroic beam splitter 1525. In embodiments, the first dichroic beam splitter 1525 may be configured in an optical path between the first light generating device 110 and the first luminescent material 210. Especially, in embodiments (as depicted here), the first dichroic beam splitter 1525 may be configured to transmit at least part of the (first and optionally third) device light 101 (,111, 131) received by the first dichroic beam splitter 1525, and reflect at least part of the first luminescent material light 211 received by the first dichroic beam splitter 1525. Alternatively, in embodiments (not depicted), the first dichroic beam splitter 1525 may be configured to reflect at least part of the (first and optionally third) device light 101(, 111,131) received by the first dichroic beam splitter 1525 and transmit at least part of the first luminescent material light 211 received by the first dichroic beam splitter 1525.

[0154] Furthermore, in embodiments, the light generating system may comprise a second dichroic beam splitter 2525. In embodiments, the second dichroic beam splitter 2525 may be configured in an optical path between the second light generating device 120 and the second luminescent material 220. Especially, in embodiments (as depicted here), the second dichroic beam splitter 2525 may be configured to transmit at least part of the (second and optionally first and / or third) device light 101(, 121, and optionally 111,131) received by the second dichroic beam splitter 2525and reflect at least part of the second luminescent material light 221 received by the second dichroic beam splitter 2525. Alternatively, in embodiments (not depicted), the second dichroic beam splitter 2525 may be configured to reflect at least part of the (second and optionally first and / or third) device light 101 (, 121 , and optionally 111,131) received by the second dichroic beam splitter 2525 and transmit at least part of the second luminescent material light 221 received by the second dichroic beam splitter 2525. In specific embodiments, the second dichroic beam splitter 2525 may be configured to (i) transmit at least part of the (second and optionally first and / or third) device light 101 (, 121 , and optionally 111,131) received by the second dichroic beam splitter 2525, (ii) reflect at least part of the second luminescent material light 221 received by the second dichroic beam splitter 2525, and (iii) transmit at least part of the first luminescent material light 211 received by the second dichroic beam splitter 2525.

[0155] The light generating system may further comprise one or more of collimating optics, condensing optics, homogenizing optics, and integrating optics. For example, as depicted in Fig. 1 A, the light generating system may comprise one or more lenses 560 configured to focus light onto components such as the luminescent materials 210,220 and the dichroics 1525,2525.

[0156] Furthermore, in embodiments, the light generating system 1000 may further comprise a control system 300. Especially, the control system 300 may be configured to control a spectral power distribution of the system light 1001 by controlling the one or more light generating devices 100. Moreover, in embodiments, the control system 300 may be configured to control a correlated color temperature (and / or a color rendering index) of the system light 1001 by controlling the one or more light generating devices 100.

[0157] Yet further, in embodiments, the one or more light generating devices 100 may comprise a third light generating device 130 configured to generate third device light 131. Especially, in embodiments, the third device light 131 may comprise blue light. In embodiments, the third device light 131 may further comprise linearly polarized light. The light generating system 1000 may further comprise a polarizing beam splitter 1500 configured downstream of the third light generating device 130. The polarizing beam splitter 1500 may be configured to transmit third device light 131 having one of a first linear polarization and a second linear polarization.

[0158] Furthermore, in embodiments, the light generating system 1000 may comprise a (reflective) diffuser 710 and a polarization changing element 720 (such as e.g. a X / 4 waveplate). In embodiments, the polarizing beam splitter 1500 may be configured to direct (i.e., transmit as depicted here or reflect (not depicted)) the third device light 131 to the polarization changing element 720. The polarization changing element 720 may be configured to change first linearly polarized light into first circularly polarized light, or vice versa. Additionally or alternatively, the polarization changing element may be configured to change second circularly polarized light into second linearly polarized light, or vice versa. Hence, in embodiments, the polarization changing element 720 may be configured to change linearly polarized third device light 131 into circularly polarized third device light 131 and to direct the circularly polarized third device light 131 to the diffuser 710. At the diffuser 710 the circularly polarized third device light 131 may be diffused, such that circularly polarized diffused (third) device light 711 may be provided (e.g. as depicted here reflected back to the polarization changing element 720). In embodiments, the polarization changing element 720 may the ben configured to change the circularly polarized diffused device light 711 into linearly polarized diffused device light 711 (having a linear polarization different from the third device light 131) and to direct the linearly polarized diffused device light 711 to the polarizing beam splitter 1500. The polarizing beam splitter 1500 may, in embodiments, be configured to direct (i.e., reflect as depicted here or transmit (not depicted)) the diffused device light 711 to the first dichroic beam splitter 1525.

[0159] In such embodiments, the first dichroic beam splitter 1525 and the second dichroic beam splitter 2525 may be configured to transmit (as depicted here) of reflect (not depicted) the diffuse device light 711. As such, in embodiments, in the first operational mode of the light generating system 1000 the system light 1001 may comprise (i) part of the third device light 131, (ii) first luminescent material light 211, and (iii) second luminescent material light 221. Especially, in embodiments, in the first operational mode of the light generating system 1000 the system light 1001 may comprise (i) part of the diffused (third) device light 711, (ii) first luminescent material light 211, and (iii) second luminescent material light 221.

[0160] Figs. 2 schematically depicts some alternative embodiments of the light generating system 1000 of the invention where at least part of the second support 820 may be configured in the transmissive mode. In Fig. 2A subfigure I, in embodiments, the movable support (here especially the second support 820) may comprise a phosphor track comprising the second luminescent material 220 (as depicted in subfigure II). Furthermore, in embodiments, the movable support (here especially the second support 820) may comprise an opening 850. The opening 850 may especially be configured to transmit (blue) first device light 111 received by the opening 850 to the stationary support (here the first support 810). In such embodiments, the opening 850 may comprise a (through-)hole or a slit. Especially, as depicted here, the opening 850 may comprise a slit. In embodiments, the opening 850 (especially the slit) may have an opening width Wo. In embodiments, the opening 850 may be a physical opening configured to transmit at least part of the first device light 111 (received by the second support 820) to the first support 810.. Alternatively, in embodiments, the opening 850 may comprise a light-transmissive material configured to transmit at least part of the first device light 111 (received by the second support 820) to the first support 810. Furthermore, in such embodiments, the opening 850 may be configured to transmit at least part of the first luminescent material light 211 (received from the first luminescent material 210) to the first dichroic beam splitter 1525. In Fig. 2B, in embodiments, the movable support (here especially the second support 820) may also comprise a phosphor track (as depicted in subfigure III) comprising the second luminescent material 220. As depicted, in such embodiments, the movable support (here especially the second support 820) may further comprise an opening 850. The opening 850 may especially be configured to transmit (blue) first device light 111 received by the opening 850 to the stationary support (here the first support 810). Hence, in such embodiments, the opening 850 may comprise a (through-)hole or a slit.

[0161] Here, Fig. 2B subfigure I especially depicts a point in time where (during operation of the light generating system 1000) the second support 820 may be configured to transmit first device light 111 to the first support 810 (via the first dichroic beam splitter 1525). On the other hand, Fig. 2B subfigure II especially depicts a point in time where (during operation of the light generating system 1000) the second luminescent material 220 may be configured to convert first device light 111 into the second luminescent material light 221 and reflect said second luminescent material light 221 to the second dichroic beam splitter 2525. Hence, in such embodiments, one light generating device 100 (e.g. the first light generating device 110 as depicted) may be configured to provide device light 101 to both the first luminescent material 210 and the second luminescent material 220.

[0162] In alternative embodiments (not depicted), the movable support may comprise a phosphor track comprising the second luminescent material 220 and a reflector configured to reflect (blue) device light received by the reflector to the stationary support.

[0163] Hence, in embodiments, the light generating system 1000 may provide high brightness white system light have a tunable correlated color temperature and / or color rendering index. Fig. 3 schematically depicts an example of a spectral power distribution as may be achieved using the light generating system 1000 of the invention. By (individually) controlling the one or more light generating devices 100 the amount of blue (device light) power, green-yellow (e.g. LuAG) power, and red (luminescent) power relative to each other can be tuned, therewith changing the CCT and CRI of the system light, as can be seen in the below table of modelled data for the light generating system 1000.

[0164] Fig. 4 schematically depicts an embodiment of a luminaire 2 comprising the light generating system 1000 as described above. Reference 301 indicates a user interface which may be functionally coupled with the control system 300 comprised by or functionally coupled to the light generating system 1000. Fig. 4 also schematically depicts an embodiment of lamp 1 comprising the light generating system 1000. Reference 3 indicates a projector device or projector system, which may be used to project images, such as at a wall, which may also comprise the light generating system 1000. Hence, Fig. 4 schematically depicts embodiments of a lighting device 1200 selected from the group of a lamp 1, a luminaire 2, a projector device 3, a disinfection device, a photochemical reactor, and an optical wireless communication device, comprising the light generating system 1000 as described herein. In embodiments, such lighting device may be a lamp 1, a luminaire 2, a projector device 3, a disinfection device, or an optical wireless communication device. Lighting device light escaping from the lighting device 1200 is indicated with reference 1201. Lighting device light 1201 may essentially consist of system light 1001, and may in specific embodiments thus be system light 1001. Reference 1300 refers to a space, such as a room. Reference 1305 refers to a floor and reference 1310 to a ceiling; reference 1307 refers to a wall.

[0165] The term “plurality” refers to two or more.

[0166] The terms “substantially” or “essentially” herein, and similar terms, will be understood by the person skilled in the art. The terms “substantially” or “essentially” may also include embodiments with “entirely”, “completely”, “all”, etc. Hence, in embodiments the adjective substantially or essentially may also be removed. Where applicable, the term “substantially” or the term “essentially” may also relate to 90% or higher, such as 95% or higher, especially 99% or higher, even more especially 99.5% or higher, including 100%.

[0167] The term “comprise” also includes embodiments wherein the term “comprises” means “consists of’.

[0168] The term “and / or” especially relates to one or more of the items mentioned before and after “and / or”. For instance, a phrase “item 1 and / or item 2” and similar phrases may relate to one or more of item 1 and item 2. The term "comprising" may in an embodiment refer to "consisting of' but may in another embodiment also refer to "containing at least the defined species and optionally one or more other species". Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

[0169] The devices, apparatus, or systems may herein amongst others be described during operation. As will be clear to the person skilled in the art, the invention is not limited to methods of operation, or devices, apparatus, or systems in operation.

[0170] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims.

[0171] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

[0172] Use of the verb "to comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”.

[0173] The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

[0174] The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In a device claim, or an apparatus claim, or a system claim, enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. In yet a further aspect, the invention (thus) provides a software product, which, when running on a computer is capable of bringing about (one or more embodiments of) the method as described herein.

[0175] The invention also provides a control system that may control the device, apparatus, or system, or that may execute the herein described method or process. Yet further, the invention also provides a computer program product, when running on a computer which is functionally coupled to or comprised by the device, apparatus, or system, controls one or more controllable elements of such device, apparatus, or system. The invention further applies to a device, apparatus, or system comprising one or more of the characterizing features described in the description and / or shown in the attached drawings. The invention further pertains to a method or process comprising one or more of the characterizing features described in the description and / or shown in the attached drawings.

[0176] The various aspects discussed in this patent can be combined in order to provide additional advantages. Further, the person skilled in the art will understand that embodiments can be combined, and that also more than two embodiments can be combined. Furthermore, some of the features can form the basis for one or more divisional applications.

Claims

CLAIMS:

1. A light generating system (1000) comprising one or more light generating devices (100), a first luminescent material (210), a second luminescent material (220), a first support (810), and a second support (820), wherein: the one or more light generating devices (100) are configured to generate device light (101); wherein the one or more light generating devices (100) comprise one or more solid state light sources (10) selected from laser diodes and superluminescent diodes; wherein the device light (101) comprises violet and / or blue light; the first luminescent material (210) is configured to convert at least part of the device light (101) received by the first luminescent material (210) into first luminescent material light (211); wherein the first luminescent material (210) comprises a luminescent material of the type AsBsOn Ce, wherein A comprises one or more of Y, La, Gd, Tb and Lu, and wherein B comprises one or more of Al, Ga, In and Sc; wherein the first luminescent material (210) is configured in the reflective mode; the second luminescent material (220) is configured to convert at least part of the device light (101) received by the second luminescent material (220) into second luminescent material light (221); wherein the second luminescent material light (221) has a peak emission wavelength in the red wavelength range; wherein the second luminescent material (220) is configured in the reflective mode; the first support (810) is configured to support the first luminescent material (210); the second support (820) is configured to support the second luminescent material (220); wherein the first support (810) is a stationary support and the second support (820) is a movable support being configured to move during operation of the light generating system (10000) in a first operational mode of the light generating system (1000); the light generating system (1000) is configured to generate system light (1001), wherein in the first operational mode of the light generating system (1000): the system light (1001) comprises (i) part of the device light (101), (ii) the first luminescent material light (211), and (iii) the second luminescent material light (221), and wherein the system light (1001) has a correlated color temperature selected from the range of 1500-10000 K and a color rendering index of at least 65.

2. The light generating system (1000) according to claim 1, wherein the first luminescent material (210) is configured to generate green-yellow first luminescent material light (211).

3. The light generating system (1000) according to any one of the preceding claims, wherein the second support (820) is a rotatable support comprises a phosphor track comprising the second luminescent material (220).

4. The light generating system (1000) according to claim 3, wherein the rotatable support is comprised by a wheel-type support, a cylinder-type support, or a conveyor-belt type support.

5. The light generating system (1000) according to any one of the preceding claims 3-4, wherein the rotatable support comprises an opening configured to transmit device light (101) received by the opening (850) to the stationary support.

6. The light generating system (1000) according to any one of the preceding claims 3-4, wherein the rotatable support comprises a reflector configured to reflect device light (101) received by the reflector to the stationary support.

7. The light generating system (1000) according to any one of the preceding claims, wherein the first support (810) comprises a thermally conductive element (815), configured to support the first luminescent material (210); wherein the thermally conductive element (815) comprises one or more of a heat sink, a heat spreader, and a two-phase cooling device.

8. The light generating system (1000) according to any one of the preceding claims, wherein the first luminescent material (210) comprises the luminescent material of the type AsBsO Ce, wherein A comprises for at least 67 at% Lu.

9. The light generating system (1000) according to any one of the preceding claims, wherein the second luminescent material (210) comprises one or more of (i) (Ba,Sr,Ca)AlSiN3:Eu, (ii) (Ba,Sr,Ca)2SisN8:Eu, (iii) Sic, zAfiOzNs _z:Pr, wherein 0 < z < 2.0,(iv) (Sri-xEux)aSipAl705N<o, wherein 0 < x <1, 0 < a < 3, 5 < P < 7, 3 < y < 5, 0.5 < 5 < 0.8, and 5 < co < 15, and (v) M’zM2-2zAX6 doped with tetraval ent manganese; wherein M’ comprises an alkaline earth cation; wherein M comprises an alkaline cation, and z is in the range from 0 to 1; wherein A comprises a tetraval ent cation; and wherein X comprises a monovalent anion, at least comprising fluorine.

10. The light generating system (1000) according to any one of the preceding claims, wherein: the one or more light generating devices (100) comprise a first light generating device (110) configured to generate first device light (111); wherein the first luminescent material (210) is configured to convert at least part of the first device light (111) received by the first luminescent material (210) into first luminescent material light (211); wherein the first device light (111) comprises blue light; and the one or more light generating devices (100) comprise a second light generating device (120) configured to generate second device light (121); wherein the second luminescent material (220) is configured to convert at least part of the second device light (121) received by the second luminescent material (220) into second luminescent material light (221); wherein the second device light (121) comprises blue light.

11. The light generating system (1000) according to any one of the preceding claims, wherein: the one or more light generating devices (100) comprise a third light generating device (130) configured to generate third device light (131); wherein the third device light (131) comprises blue light; and in the first operational mode of the light generating system (1000) the system light (1001) comprises (i) part of the third device light (131), (ii) first luminescent material light (211), and (iii) second luminescent material light (221).

12. The light generating system (1000) according to any one of the preceding claims, comprising: a first dichroic beam splitter (1525) configured to transmit at least part of the device light (101) and reflect at least part of the first luminescent material light (211), or configured to reflect at least part of the device light (101) and transmit at least part of the first luminescent material light (211);a second dichroic beam splitter (2525) configured to transmit at least part of the device light (101) and reflect at least part of the second luminescent material light (221), or configured to reflect at least part of the device light (101) and transmit at least part of the second luminescent material light (221).

13. The light generating system (1000) according to any one of the preceding claims, wherein the first luminescent material (210) and / or the second luminescent material (210) are configured in a full-conversion mode.

14. The light generating system (1000) according to any one of the preceding claims, further comprising a control system (300), wherein the control system (300) is configured to control a spectral power distribution of the system light (1001) by controlling the one or more light generating devices (100).

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

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