EP4544218A1

EP4544218A1 - Laser source lightguide spider module

Info

Publication number: EP4544218A1
Application number: EP23733371.1A
Authority: EP
Inventors: Marcellus Jacobus Johannes Van Der Lubbe; Hugo Johan Cornelissen
Original assignee: Signify Holding BV
Current assignee: Signify Holding BV
Priority date: 2022-06-23
Filing date: 2023-06-20
Publication date: 2025-04-30
Also published as: JP2025524448A; WO2023247568A1; CN119404047A

Abstract

: A light generating system (1000) comprising (i) a beam combiner body (500), and (ii) k arrangements (1050); wherein the beam combiner body (500) comprises a first face (501), wherein the first face (501) comprises n grooves (510) extending from a central cavity (520), wherein n≥2; wherein the n grooves (510) have a first end (513) and a second end (514), wherein the first end (513) is configured more remote from the central cavity (520) than the second end (514), and wherein the second end (514) faces the central cavity (520); wherein each of the k arrangements (1050) comprises a light generating device (100), a luminescent body (210), a first optical element (551), and a light guide body (530); wherein 2≤k≤n; wherein the light generating device (100) is configured to generate device light (101), wherein the light generating device (100) comprise one or more light sources selected from the group of lasers and superluminescent diodes; wherein the luminescent body (210) comprises a luminescent material (200) configured to convert at least part of the device light (101) into luminescent material light (201); wherein the first optical element (551) comprises one or more of a beam shaping reflective element and a lens; wherein the light guide body (530) is configured in one of the grooves (510); wherein the light guide body (530) is light transmissive for the luminescent material light (201); wherein the light guide body (530) has a first body end (531) and a second body end (532), wherein the first body end (531) is configured more remote from the central cavity (520) than the second body end (532); wherein the luminescent body (210) is configured downstream of the light generating device (100); the first optical element (551) is configured downstream of the luminescent body (210); and the first body end (531) of the light guide body (530) is configured downstream of the first optical element (551).

Description

LASER SOURCE LIGHTGUIDE SPIDER MODULE

FIELD OF THE INVENTION

The invention relates to a system, especially for generating light, and to a light generating device comprising such system.

BACKGROUND OF THE INVENTION

Laser light array assemblies are known in the art. US20200026169A1, for instance, describes an illumination system that includes a laser array assembly including a laser configured to generate a laser light; a crystal phosphor waveguide adjacent to the laser and in the laser light configured to generate a luminescent light based on receiving the laser light, and direct the luminescent light away from a base end; and a compound parabolic concentrator (CPC), coupled to the crystal phosphor waveguide opposite the base end, configured to collect the luminescent light from the crystal phosphor waveguide, and project the luminescent light away from the crystal phosphor waveguide.

US2020/400299A1 discloses a lighting device with at least one laser configured to emit excitation light, a substrate, a reflective layer, a wavelength conversion layer, and a light guiding element. The substrate is made of material with a high thermal conductivity and provided with a notch. The laser is received in a sidewall of the notch. The reflective layer covers walls of the notch and is configured to reflect the excitation light. The wavelength conversion layer is provided on a part of the reflective layer and configured to perform wavelength conversion on the excitation light to obtain excited light. The light guiding element covers an opening of the notch and configured to guide the excitation light and the excited light, to obtain light to be emitted by the light source system.

WO2021/063878 Al discloses a light generating device configured to generate device light and comprising: a first light source for UV or blue first light source light, a second light source for green light, a third light source for red light, a fourth light source for blue light. The device further comprises a first luminescent material configured to convert at least part of the light of the first light source light into yellow or green luminescent material light. An optical element combines the light of the various light sources to white light. SUMMARY OF THE INVENTION

While white LED sources can give an intensity of e.g. up to about 300 lm/mm²; static phosphor converted laser white sources can give an intensity even up to about 20.000 lm/mm². Ce doped garnets (e.g. YAG, LuAG) may be the most suitable luminescent convertors which can be used for pumping with blue laser light as the garnet matrix has a very high chemical stability. Further, at low Ce concentrations (e.g. below 0.5%) temperature quenching may only occur above about 200 °C. Furthermore, emission from Ce has a very fast decay time so that optical saturation can essentially be avoided. Assuming e.g. a reflective mode operation, blue laser light may be incident on a phosphor. This may in embodiments realize almost full conversion of blue light, leading to emission of converted light. It is for this reason that the use of garnet phosphors with relatively high stability and thermal conductivity is suggested. However, also other phosphors may be applied. Heat management may remain an issue when extremely high-power densities are used.

High brightness light sources can be used in applications such as projection, stage-lighting, spot-lighting and automotive lighting. For this purpose, laser-phosphor technology can be used wherein a laser provides laser light and e.g. a (remote) phosphor converts laser light into converted light. The phosphor may in embodiments be arranged on or inserted in a heatsink for improved thermal management and thus higher brightness.

One of the problems that may be associated with such (laser) light sources is the heat management of the (ceramic) phosphor. Other problems associated with such laser light sources may be the desire to create compact high power devices.

Further, lighting modules may have mirrors, dichroic filters and/or beam combiners, which may be used to extract light from different light sources. However, the use of such optical elements may consume valuable space which may not always be suitably accommodated in a lighting module.

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 abovedescribed 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.

In embodiments, the invention provides a light generating system configured to generate system light, comprising (i) a beam combiner body, and (ii) k arrangements. Especially, the beam combiner body may comprise a first face, wherein the first face may comprise n grooves extending from a central cavity and configured to provide light directed towards the central cavity. Especially, n>2. In embodiments, the n grooves may have a first end and a second end. More especially, the first end may be configured more remote from the central cavity than the second end. Yet, in specific embodiments the second end may face the central cavity. Further, in embodiments, each of the k arrangements may comprise a light generating device, a luminescent body, a first optical element, and a light guide body. Especially, 2<k<n. In embodiments, the light generating device may be configured to generate device light. Especially, the light generating device may comprise one or more light sources selected from the group of lasers and superluminescent diodes. Further, in embodiments, the luminescent body may comprise a luminescent material configured to convert at least part of the device light into luminescent material light. The first optical element, in embodiments, may comprise one or more of a beam shaping reflective element and a lens. Further, in embodiments, the light guide body may be configured in one of the grooves. Especially, the light guide body may be light transmissive for the luminescent material light. Further, in embodiments, the light guide body may have a first body end and a second body end. Especially, the first body end may be configured more remote from the central cavity than the second body end. The light guide body is configured to propagate light to the central cavity via the second body end. In embodiments, the luminescent body may be configured downstream of the light generating device, the first optical element may be configured downstream of the luminescent body, and the first body end of the light guide body may be configured downstream of the first optical element. The system light comprises one or more of the device light and the luminescent material light, and wherein, during operation of the light generating system, the system light emanates from the central cavity.

Hence, in specific embodiments, the invention provides a light generating system comprising (i) a beam combiner body, and (ii) k arrangements; wherein the beam combiner body comprises a first face, wherein the first face comprises n grooves extending from a central cavity, wherein n>2; wherein the n grooves have a first end and a second end, wherein the first end is configured more remote from the central cavity than the second end; and wherein each of the k arrangements comprises a light generating device, a luminescent body, a first optical element, and a light guide body; wherein 2<k<n; wherein the light generating device is configured to generate device light, wherein the light generating device comprise one or more light sources selected from the group of lasers and superluminescent diodes; wherein the luminescent body comprises a luminescent material configured to convert at least part of the device light into luminescent material light; wherein the first optical element comprises one or more of a beam shaping reflective element and a lens; wherein the light guide body is configured in one of the grooves; wherein the light guide body is light transmissive for the luminescent material light; wherein the light guide body has a first body end and a second body end, wherein the first body end is configured more remote from the central cavity than the second body end; wherein the luminescent body is configured downstream of the light generating device; the first optical element is configured downstream of the luminescent body; and the first body end of the light guide body is configured downstream of the first optical element. More especially, in specific embodiments, the invention provides a light generating system comprising (i) a beam combiner body, and (ii) k arrangements; wherein the beam combiner body comprises a first face, wherein the first face comprises n radially arranged grooves radially extending from a central cavity, wherein n>2; wherein the n grooves have a first end and a second end, wherein the first end is configured more remote from the central cavity than the second end; and wherein each of the k arrangements comprises a light generating device, a luminescent body, a first optical element, and a light guide body; wherein 2<k<n; wherein the light generating device is configured to generate device light, wherein the light generating device comprise one or more light sources selected from the group of lasers and superluminescent diodes; wherein the luminescent body comprises a luminescent material configured to convert at least part of the device light into luminescent material light; wherein the first optical element comprises one or more of a beam shaping reflective element and a lens; wherein the light guide body is configured in one of the grooves; wherein the light guide body is light transmissive for the luminescent material light; wherein the light guide body has a first body end and a second body end, wherein the first body end is configured more remote from the central cavity than the second body end; wherein the luminescent body is configured downstream of the light generating device; the first optical element is configured downstream of the luminescent body; and the first body end of the light guide body is configured downstream of the first optical element. Hence, in embodiments, the invention may provide a laser source lightguide spider-like module.

With such system, efficiency may be relatively high as a large area of the luminescent body may be in thermal contact with a thermally conductive material, such as a heatsink. Further, a relatively small device, e.g. a package, may be provided which may be able to provide light with a relatively high intensity. The present invention may provide a compact transmissive configuration or a compact reflective configuration, with improved heat removal from the phosphor. Further a system may be provided having a controllable color point, such as correlated color temperature of the system light generated by the system. Such a system may further provide the advantage of a simple mechanical solution to combine light from different sources into a single extraction body. As mentioned above, the invention may provide a light generating system (or “system”) comprising (i) a beam combiner body, and (ii) k arrangements.

In embodiments, the beam combiner body may comprise a first face, wherein the first face comprises n grooves extending from a central cavity. The beam combiner may be used to combine light from multiple sources, especially in the central cavity. Each of the n grooves may provide light directed towards the central cavity, which may then be combined and reflected in the central cavity. Here “light” may refer to the device light or the luminescent material light. The first face, in embodiments may be larger than the central cavity.

Especially, the grooves may extend from the central cavity in the direction of an edge of the beam combiner body. Hence, especially, the first face comprises n substantially radially arranged grooves substantially radially extending from the central cavity. Hence, the grooves may be configured parallel to a radius or may be slightly offset. Therefore, the first face comprises n substantially radially arranged grooves substantially radially extending from the central cavity. More especially, the first face may comprise n radially arranged grooves radially extending from a central cavity.

In embodiments, the first face may have a first face diameter Df. In further embodiments, the central cavity may have a central cavity diameter De. Especially, in embodiments 0.001<Dc/Df<0.25, more especially 0.01<Dc/Df<0.1. In embodiments, the first face diameter Df may be selected from the range of 1-100 mm, like especially selected from the range of 2-20 mm.

Light may emanate from the central cavity. This light may be the system light. Hence, the system light generated by the light generating system may comprise one or more of device light and luminescent material light that escapes from the central cavity. As can be derived from the above, the central cavity may have a reflective bottom. The central cavity may also have walls that are reflective.

Especially, the n ((substantially) radially) arranged grooves may have groove lengths (L). Seen from the central cavity, the grooves may be configured ((substantially) radially) extending from the central cavity. The central cavity may be an indentation in the beam combiner body. In embodiments, it is not a through hole, but a cavity or indentation in the beam combiner body. The depth of the cavity and the grooves may in embodiments essentially be the same. The central cavity may have a substantially circular shape.

The length of the grooves may in embodiments have values of 0.5*Df-0.5*Dc. Shorter grooves, however, are not excluded, but then mirrors may be available in the groove, or the groove might have a mirroring end. Herein, the invention is explained in relation to grooves having a length from an edge of the first face to the central cavity.

Further, the beam combiner may have a substantially circular shape. For instance, the beam combiner may have a cylindrical shape. For instance, the central cavity may have a cylindrical shape. The grooves may extend from the central cavity like spokes in a wheel may extend from a central hub. Herein, however, the central hub and the spokes are hollow elements in the beam combiner body. Unless indicated otherwise, the grooves may especially be elongated grooves, which are essentially radially arranged.

The beam combiner may comprise a reflective material, such as one or more metals, and/or may comprise a reflective coating of a reflective material. The reflective material may be a specular reflective material, such as silver, copper, or aluminum. The reflective material may also be diffuse reflective material, such as a coating of a particulate white material. Suitable reflective material for reflection may be selected from the group consisting of TiCh, BaSCU, MgO, and AI2O3. Further, the beam combiner may comprise a thermally conductive material (see further below).

As indicated above, the first face may comprise n ((substantially) radially) arranged grooves. Especially, n>2. More especially, n>3. In embodiments, n may be selected from 4, 6, 8, 10, 12, 16, and 18. However, higher numbers may also be possible. Especially, n may be selected from the range of 3-18.

In embodiments, the n grooves may have a first end and a second end. Especially, the first end may be configured more remote from the central cavity than the second end. Further, the second end may, in embodiments, face the central cavity. In embodiments, the second end may have a (rectangular) cross-section having a normal, which may be parallel to a groove axis, and which normal may be directed into the central cavity. More especially, the second end may (also) be configured at a radius Dc/2 of the central cavity. The central cavity may comprise a wall, wherein the second ends are openings. However, with larger number of grooves the second ends may be adjacent to each other without any intermediate wall parts.

During operation, light may travel in a path along the axis of the groove(s). Typically, the light may travel from the one end to the other, especially from the first end to the second end. In embodiments, the groove(s) may comprise the light generating device at one end, such as at the first end. Hence, light from the light generating device(s) may travel along the (respective) grooves from the first end to the second end. Alternatively, in embodiments, the light generating device(s) may (also) be configured outside of the groove(s) such that the light produced by the light generating device(s) is directed to the beam combiner body via the first end of the groove(s). Further, in embodiments, additional optical elements may be used to reflect or transmit light from the light generating device(s) to the first end of each of the beam combiner body. Hence, in embodiments, the light generating device(s) may not be configured along the axis of the groove(s), for example the light generating device(s) may be configured perpendicular to the axis of the groove(s) and may comprise reflectors to reflect the light into the first face of each groove.

In embodiments, two or more of the n grooves may comprise the k arrangements. It is not necessary that all the n ((substantially) radially) arranged grooves comprise an arrangement. In embodiments, only k from the n grooves may comprise an arrangement. Especially, 2<k<n, such as 4<k<n, like in embodiments 6<k<n. Naturally, the number of arrangements (k) may in embodiments not exceed the number of radial grooves (n). In embodiments, the light generating system may comprise at least 2 arrangements, such as at least 4 arrangements, especially at least 6 arrangements.

An arrangement here may refer to a number of elements (which may further comprise optical elements) oriented in a specific sequence or order. In embodiments, each arrangement may comprise a light generating device, a luminescent body, a first optical element, and a light guide body.

Hence, in embodiments the (each) arrangement may comprise a light generating device. Especially, the light generating device may be a device to generate device light. However, the light generating device may not be not limited only to a device to generate device light i.e. in embodiments, the light generating device may also comprise additional components or a package of light generating elements such as mirrors, lenses, reflectors, collameters, etc. to facilitate generation and propagation of light Hence, the light generating device may not be limited to a light source, but may be a device comprising the light source and additional elements to provide or generate device light.

Further, in embodiments, there may be at least two different light generating devices, configured to generate device light having different spectral power distributions, wherein the device light of one type of the at least two light generating devices is used to generate device light, and wherein the device light of another type of the at least two light generating devices may be used to admix in the system light via reflection at the central cavity.

In embodiments, the (each) light generating device may comprise one or more light sources. The term “light source” may in principle relate to any light source known in the art. It may be a conventional (tungsten) light bulb, a low pressure mercury lamp, a high pressure mercury lamp, a fluorescent lamp, a LED (light emissive diode). The light source may especially be configured to generate device light having an optical axis (O), (a beam shape,) and a spectral power distribution.

In embodiments, the one or more light sources may comprise one or more lasers. The term “laser” may especially refer to a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. Hence, the light generating device(s) may comprise one or lasers. In embodiments, the one or more light generating devices may comprise one or more laser diodes. In embodiments, the one more light sources may comprise one or more superluminescents diode. Here, a “superluminescenf ’ diode may refer to a diode that works on the principle of superluminescence. Further details (and types) of the lasers and superluminescent diodes in embodiments are explained further below.

In embodiments, each of the k arrangements may comprise a luminescent body. Especially, the luminescent body may comprise a luminescent material configured to convert at least part of the device light into luminescent material light. In embodiments, the light source may be configured to provide primary radiation and part of the primary radiation may be converted into secondary radiation. Secondary radiation may be based on conversion by a luminescent material. The secondary radiation may therefore also be indicated as luminescent material light (or “luminescent material radiation” or “converted light”).

The light of the light generating devices having different spectral power distributions may be used for different luminescent bodies comprising different luminescent materials. In this way, the spectral power distribution of the light generating device may be matched with the excitation spectrum of the respective luminescent material.

The term “luminescent material” especially refers to a material that can convert first radiation, especially one or more of UV radiation and blue radiation, into second radiation. In general, the first radiation and second radiation have different spectral power distributions. Hence, instead of the term “luminescent material”, also the terms “luminescent converter” or “converter” may be applied. In general, the second radiation has a spectral power distribution at larger wavelengths than the first radiation, which is the case in the so- called down-conversion. In specific embodiments, however the second radiation has a spectral power distribution with intensity at smaller wavelengths than the first radiation, which is the case in the so-called up-conversion. Luminescent material and embodiments comprising such are discussed in more detail (see further below). In embodiments, luminescent material light of different luminescent bodies having different spectral power distributions may lead to system light having different correlated color temperatures when controlling the light generating devices. In embodiments, the system light may have a controllable CCT, with a possible difference between two possible CCT values of at least 500 K, more especially at least 1000 K, like at least 2000 K.

In embodiments, each arrangement may comprise a first optical element. Especially, the (each) first optical element may comprise one or more of a beam shaping reflective element and a lens. The light generating device (or light source) may provide light at a wide beam angle. Hence, it may be desirable to focus this beam into a narrower beam. In embodiments, the first optical element may therefore comprise a lens or a beam shaping reflective element. The first optical element may focus a wide beam of light into a narrower beam of light. The first optical element may e.g. be used for shaping the device light into a relatively collimated beam, such as in embodiments <2° (FWHM). It will be apparent to the skilled person that “FWHM” refers to full width at half maximum. Especially, the beam shaping reflective element may comprise a collimator (or “collimator element”).

Further, in embodiments, each of the k arrangements may comprise the light guide body. The light guide body may also be indicated as “lightguide body”, light-guide body”, or “first optical body”. Especially, the (each) light guide body may be configured in one of the grooves. More especially, the (each) light guide body may be light transmissive for the luminescent material light. In embodiments, the (each) light guide body may have a first body end and a second body end. Especially, the first body end may be configured more remote from the central cavity than the second body end.

The light guide body may have a light guide body height, which may be determined parallel to the groove wherein the light guide body height may be shorter than the groove length. Hence, especially the light guide body has a light guide body height (Hl) smaller than the groove length (L).

In embodiments, the (each) light guide body may be a ceramic body or a single crystalline body. Especially, the (each) light guide body may comprise a light transmissive body, for example a glass body which may be transmissive for the luminescent material light. In embodiments, the (each) light guide body may comprise a polymeric body.

In embodiments, the (each) light guide body may be operated in a transmissive mode, wherein the device light at least partly converted by the luminescent material propagates during operation of a respective light generating device through the ((substantially) radially) arranged groove wherein the light guide body is configured, in a direction of the central cavity. Hence, the device light and/or luminescent light may propagate in the groove in a direction of the central cavity. Therefore, the device light to be at least partly converted by the luminescent material may propagate during operation of a respective light generating device in a direction of the central cavity through the same ((substantially) radially) arranged groove (as) wherein the light guide body is configured.

The first body end or the second body end (or both) may have any shape. In embodiments, the first body end or the second body end (or both) may comprise two (essentially parallel) faces, defining a length (of the light guide body). Further, the light guide body may comprise an edge face, bridging a distance between the first body end or the second body end.

In embodiments, the (each) light guide body may have lateral dimensions width or length (W1 or LI) or diameter (D) and a thickness or height (Hl). In embodiments, (i) D>H1 or (ii) and W1>H1 and/or L1>H1. In specific embodiments, Ll<10 mm, such as especially Ll<5mm, more especially Ll<3mm, most especially Ll<2 mm. In specific embodiments, Wl<10 mm, such as especially Wl<5mm, more especially Wl<3mm, most especially Wl<2 mm. In specific embodiments, Hl<10 mm, such as especially Hl<5mm, more especially Hl<3mm, most especially Hl<2 mm. In specific embodiments, D<10 mm, such as especially D<5mm, more especially D<3mm, most especially D<2 mm. In specific embodiments, the light guide body may have in embodiments a thickness in the range 50 pm - 1 mm. Further, the light guide body may have lateral dimensions (width/diameter) in the range 100 pm - 10 mm. In yet further specific embodiments, (i) D>H1 or (ii) W1>H1 and W1>H1. Especially, the lateral dimensions like length, width, and diameter are at least 2 times, like at least 5 times, larger than the height. In specific embodiments, the first body has a first length LI, a first height Hl, and a first width Wl, wherein Hl<0.5*Ll and Hl<0.5*WL For square body tiles, H1=W1. The (aforementioned) dimensions of the light guide body may apply to (each) light guide body comprised by the light generating system. However, in embodiments, the one or more light guide bodies may not (necessarily) be identical to the other light guide bodies.

The groove(s) may especially be accommodated to host such light guide body. Hence, the cross-sectional dimensions of the groove may essentially be the same as width or length (Wl or LI) of the light guide body. Especially, the fit of the light guide body in the groove may be a transition fit. Hence, the groove may have cross-sectional dimensions of essentially the width (Wl) of the light guide body and the length (LI) of the light guide body. The better the fit, the better thermal energy may be dissipated via the edge of the light guide body to the walls and bottom of the groove.

Hence, in embodiments, each of the k arrangements may comprise a light generating device, a luminescent body, a first optical element, and a light guide body.

In embodiments, the luminescent body may be configured downstream of the light generating device. Especially, the first optical element may be configured downstream of the luminescent body. More especially, the first body end of the light guide body may be configured downstream of the first optical element. Each of the k arrangements are configured as such to facilitate the propagation of light along the elements comprised by the arrangement. The light generating device may generate device light, which may be converted by the luminescent body, which may be aligned to the axis of the groove by the first optical element, which may be propagated along the axis of the groove via the light guide body. Especially, light may enter the light guide body via the first body end and be propagated to the central cavity via the second body end. Hence, in a specific embodiment, the luminescent body is configured downstream of the light generating device, the first optical element is configured downstream of the luminescent body, and the first body end of the light guide body is configured downstream of the first optical element.

The phrase “each of the k arrangements” and similar phrases, does not exclude that there in addition to the k arrangements, also other arrangements, which may have different features than described herein and claimed herein for the k arrangements.

In embodiments, at least one of the following may apply: (i) the second body end is at least partly configured in the central cavity, and the second body end is slanted, and (ii) the central cavity has a slanted reflective face.

In embodiments, to improve escape of luminescent material light from the central cavity and/or escape of device light from the central cavity, it may be desirable to have the second body end configured under an angle and/or having a slanted face directed to the central cavity. In specific embodiments, wherein the n ((substantially) radially) arranged grooves have groove axes, the second body end directed to the central cavity, may be configured under a first angle (al) with the groove axis of the groove wherein the light guide body. Especially, the first angle (al) may be selected from the range of 15-75°, such as 30- 60°, especially 40-50°.

Further, in embodiments the central cavity may have a slanted reflective face. Especially, the slanted reflective face may be reflective for device light and/or luminescent material light. Hence, the slanted reflective face may be configured under a second angle (a2), wherein the second angle (a2) may be selected from the range of 15-75°, such as 30- 60°, especially 40-50°. This may provide the cavity also a collimator function.

Hence, in a specific embodiment, at least one of the following may apply: (i) the second body end is at least partly configured in the central cavity, and the second body end is slanted, and (ii) the central cavity has a slanted reflective facet.

In embodiments, the (each) light generating device may be at least partly configured within one of the grooves and may be configured in direct or indirect thermal contact with the beam combiner body. The light generating device may during operation of the light generating system become heated (or elevated in temperature). Hence, in embodiments, the light generating device(s) may be in direct contact with the beam combiner body via the groove(s). Here, direct contact may refer to the light generating device(s) in physical contact with the groove(s), thereby heat may be conducted from the light generating device to the beam combiner body. In embodiments, the light generating device(s) may (also) be in indirect contact with the beam combiner body. That is, the light generating device may be in contact with the beam combiner body via one or more thermally conductive elements. Especially, these thermally conductive elements may comprise a thermally conductive material and hence may (also) facilitate removal of heat via conduction from the light generating device to the beam combiner body. This may be particularly useful in embodiments where the light generating device is configured outside the groove.

In embodiments, the (each) luminescent body may at least be partly configured within one of the grooves and may be configured in direct or indirect thermal contact with the beam combiner body. The (each) luminescent body may during operation of the light generating system be heated as a result of absorbing radiation from the device light or luminescent material light. Hence, in embodiments, the (each) luminescent body may be in direct contact with the beam combiner body via the groove(s). Here, direct contact may refer to the (each) luminescent body in physical contact with the groove, thereby heat may be conducted from the luminescent body to the beam combiner body. In embodiments, the (each) luminescent body may (also) be in indirect contact with the beam combiner body. That is, the (each) luminescent body may be in contact with the beam combiner body via one or more thermally conductive elements. Especially, these thermally conductive elements may comprise a thermally conductive material and hence may (also) facilitate removal of heat via conduction from the (each) luminescent body to the beam combiner body.

In embodiments, the (each) first optical element may be at least partly configured within one of the grooves and may be configured in direct (thermal contact) or indirect thermal contact with the beam combiner body. The (each) first optical element may during operation of the light generating system be heated as a result of absorbing radiation from the device light or luminescent material light. Hence, in embodiments, the (each) first optical element may be in direct contact with the beam combiner body via the groove. Here, direct contact may refer to the first optical element(s) in physical contact with the groove(s), thereby heat may be conducted from the first optical element(s) to the beam combiner body. In embodiments, the first optical element may (also) be in indirect contact with the beam combiner body. That is, the first optical element(s) may be in contact with the beam combiner body via one or more thermally conductive elements. Especially, these thermally conductive elements may comprise a thermally conductive material and hence may (also) facilitate removal of heat via conduction from the first optical element to the beam combiner body.

Especially, the (each) beam combiner may be of a material that is thermally conductive. Hence, the grooves may (also) comprise a material that is thermally conductive. Further, in embodiments, the groove surfaces may comprise a material reflective for the device light and/or reflective for the luminescent material light. Therefore, especially the (each) beam combiner body is (a) thermally conductive and/or (b) reflective for one or more of the device light and the luminescent material light. For instance, in embodiments the (each) beam combiner body may comprise a metal body or a ceramic body.

Hence, in embodiment the (each) beam combiner body may be a thermally conductive element (or may comprise a thermally conductive element). 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). In embodiments, the thermally conductive material may comprise of one or more of copper, aluminum, silver, gold, silicon carbide, aluminum nitride, boron nitride, aluminum silicon carbide, beryllium oxide, a silicon carbide composite, aluminum silicon carbide, a copper tungsten alloy, a copper molybdenum carbide, carbon, diamond, and graphite. Alternatively, or additionally, the thermally conductive material may comprise or consist of aluminum oxide. When thermally conductive material is not reflective, the grooves may be provided with a reflective coating, such as an aluminum or aluminum oxide coating. In embodiments, the (each) beam combiner body may be thermally coupled, such as physically coupled, to a heatsink or a heat spreader. The beam combiner may also be a monolithic body with a heatsink or heat spreader.

In embodiments, the (each) first optical element may have a first index of refraction nl. Especially, the (each) light guide body may have a second index of refraction n2. More especially, 1.4<n2<nl<1.8. The refractive index of the first optical element and the light guide body may, in embodiments, be selected to avoid reflection of device light or luminescent material light at the interface of the first optical element and the light guide body. Further, in embodiments, the first optical body may be optically coupled to the light guide body via a transparent film, such as an epoxy film, and/or layer with matching refractive index. Such choice of refractive indices may prevent or limit reflection of light due to total internal reflection. Moreover, at the interface of the first optical element and the light guide body, the angle of incidence of the incident light (such as device light or luminescent material light) may be lower than the critical angle. Hence, minimal reflection due to total internal reflection can be expected. Further, the first optical element may (also) comprise an anti -refl ection coating to prevent any back scattering of light. Hence, such a choice of refractive indices may facilitate transmission of the device light or the luminescent material light, such as at least 80% of the device light or luminescent material light, especially at least 95% of the device light or luminescent material light, more especially at least 99% of the device light or luminescent material light.

In embodiments, the (each) light guide body and the first optical element may comprise the same material. Hence, the (each) light guide body and the first optical element may essentially have the same refractive index. Therefore, this may provide the benefit of preventing or limiting reflection of the device light or the luminescent material light.

In embodiments, the (each) light guide body may comprise a glass, quartz, a ceramic body, or a polymeric material.

In embodiments, the luminescent body may be in thermal contact with the first optical element. Especially, the face of the luminescent body via which light escapes may have the same cross-sectional shape as the face of the first optical element via which light may enter (the first optical element). The aforementioned two faces may be in physical contact, thus, facilitating the transfer of heat between the luminescent body and the first optical element through conduction.

Further, in embodiments, the first optical element may be in contact with the light guide body. Especially, the face of the first optical element via which light escapes may have the same cross-sectional shape as the face of the light guide body (i.e. the face of the first body end) via which light enters the light guide body. The aforementioned two faces may be in physical contact, thus, facilitating the transfer of heat between the first optical element and the light guide body through conduction.

The physical contact as described above may provide the advantage of preventing undesired leakage of light (when light is transmitted along the groove via each of the elements mentioned before). Additionally, the thermal contact between the luminescent body, the first optical element and the light guide body may effectively transfer heat from these elements to the beam combiner body, thus, cooling the light generating system.

In embodiments, the light generating system may comprise a second optical body. The second optical body may at least partly extending from the central cavity. The second optical body may at least partly configured in the central cavity. However, the second optical body may also be configured external from the central cavity.

Especially, the second optical body may be configured downstream of the light guide bodies. In embodiments, the second optical body may be configured downstream of the central cavity.

Especially, the second optical body may be a dome-shaped optical body. However, the second optical body is not necessarily dome-shaped. Here, the dome-shape may refer to a geometry comprising a curved surface, for example a hemisphere.

Especially, the second optical body may provide the benefit of beamshaping the system light, such as e.g. focusing the system light in a particular direction and/or shaping into a specific beam angle. Hence, system light escaping the central cavity may undergo one or more reflections and/or one or more refractions via the optical element.

In embodiments, the second optical body may especially be configured to beamshape the luminescent material light received by the second optical body from the light guide body and/or to extract the luminescent material light from the light guide body. Further, in embodiments also part of the device light may propagate through the light guide body. Hence, the second optical body may especially be configured to beamshape the device light received by the second optical body from the light guide body and/or to extract the device light from the light guide body.

Note that, in embodiments, the second optical body may be configured outside the central cavity. In embodiments, the second optical body may be configured above the grooves and the light provided at the central cavity may be reflected in the direction of the second optical body. Hence, in embodiments, the second optical body may be configured above the grooves to capture the extracted light.

As mentioned before, in embodiments, the (each) light guide body may have a second index of refraction n2. Especially, the second optical body may have a third index of refraction n3. More especially, 0<|n3-n2|<0.4.The refractive index of the light guide body and the second optical body may, in embodiments, be selected to avoid reflection of device light and/or luminescent material light at the interface of the light guide body and the second optical body. The small difference in refractive index between the (each) light guide body and the second optical body may prevent or limit total internal reflection. Although, minimal total internal reflection can be expected at the interface of the (each) light guide body and the second optical body (on account of small incidence angles of light (such as device light or luminescent material light)), such choice of refractive indices may prevent or limit (any) reflection of light due to total internal reflection. Further, such a choice of refractive indices may facilitate transmission of the device light or the luminescent material light, such as at least 80% of the device light or luminescent material light, especially at least 95% of the device light or luminescent material light, more especially at least 99% of the device light or luminescent material light. Further, in embodiments, a roughness of the second optical body may be selected to enhance light extraction. In specific embodiments, a surface roughness RMS of the dome may be selected in the range of 50-100 pm, such as 65-85 pm, especially 70-80 pm.

In embodiments, the light guide bodies and the second optical body may be a monolithic body. Especially, the light guide bodies and the second optical body may be a single unit i.e. they may be formed from a single material.

In embodiments, the dome-shaped body may comprise a glass, quartz, a ceramic body, or a polymeric material.

Both the dome-shaped body and the light guide material may comprise light transmissive materials. These materials may be selected individually, but may in embodiments also be the same (in case the dome is available).

Especially, the material has a light transmission in the range of 50-100 %, especially in the range of 70-100%, for light having a wavelength selected from the visible wavelength range. Herein, the term “visible light” especially relates to light having a wavelength selected from the range of 380-780 nm.

The transmission (or light permeability) can be determined by providing light at a specific wavelength with a first intensity to the light transmissive material under perpendicular radiation and relating the intensity of the light at that wavelength measured after transmission through the material, to the first intensity of the light provided at that specific wavelength to the material (see also E-208 and E-406 of the CRC Handbook of Chemistry and Physics, 69th edition, 1088-1989).

In specific embodiments, a material may be considered transmissive when the transmission of the radiation at a wavelength or in a wavelength range, especially at a wavelength or in a wavelength range of radiation generated by a source of radiation as herein described, through a 1 mm thick layer of the material, especially even through a 5 mm thick layer of the material, under perpendicular irradiation with said radiation is at least about 20%, such as at least 40%, like at least 60%, such as especially at least 80%, such as at least about 85%, such as even at least about 90%.

The light transmissive material has light guiding or wave guiding properties. Hence, the light transmissive material is herein also indicated as waveguide material or light guide material. The light transmissive material will in general have (some) transmission of one or more of (N)UV, visible and (N)IR radiation, such as in embodiments at least visible light, in a direction perpendicular to the length of the light transmissive material. Without the activator (dopant) such as trivalent cerium, the internal transmission in the visible might be close to 100%.

The transmission of the light transmissive material (as such) for one or more luminescence wavelengths may be at least 80%/cm, such as at least 90%/cm, even more especially at least 95%/cm, such as at least 98%/cm, such as at least 99%/cm. This implies that e.g. a 1 cm³ cubic shaped piece of light transmissive material, under perpendicular irradiation of radiation having a selected luminescence wavelength (such as a wavelength corresponding to an emission maximum of the luminescence of the luminescent material of the light transmissive material), will have a transmission of at least 95%.

Herein, values for transmission especially refer to transmission without taking into account Fresnel losses at interfaces (with e.g. air). Hence, the term “transmission” especially refers to the internal transmission. The internal transmission may e.g. be determined by measuring the transmission of two or more bodies having a different width over which the transmission is measured. Then, based on such measurements the contribution of Fresnel reflection losses and (consequently) the internal transmission can be determined. Hence, especially, the values for transmission indicated herein, disregard Fresnel losses.

In embodiments, an anti-reflection coating may be applied to the luminescent body, such as to suppress Fresnel reflection losses (during the light incoupling process). In addition to a high transmission for the wavelength(s) of interest, also the scattering for the wavelength(s) may especially be low. Hence, the mean free path for the wavelength of interest only taking into account scattering effects (thus not taking into account possible absorption (which should be low anyhow in view of the high transmission), may be at least 0.5 times the length of the body, such as at least the length of the body, like at least twice the length of the body. For instance, in embodiments the mean free path only taking into account scattering effects may be at least 5 mm, such as at least 10 mm. The wavelength of interest may especially be the wavelength at maximum emission of the luminescence of the luminescent material. The term “mean free path” is especially the average distance a ray will travel before experiencing a scattering event that will change its propagation direction.

In embodiments, the element (or “light transmissive element”), here especially the light guide body, comprising the light transmissive material may essentially consist of the light transmissive material. In specific embodiments, the element comprising the light transmissive material may be a light transparent element.

Especially, the light transmissive element, such as the light transparent element, may in embodiments have an absorption length and/or a scatter length of at least the length (or thickness) of the light transmissive element, such as at least twice the length of the light transmissive element. The absorption length may be defined as the length over which the intensity of the light along a propagation direction due to absorption drops with 1/e. Likewise, the scatter length may be defined as the length along a propagation direction along which light is lost due to scattering and drops thereby with a factor 1/e. Here, the length may thus especially refer to the distance between a primary face and a secondary face of the light transmissive element, with the light transmissive material configured between the primary face and the secondary face.

The light transmissive material may comprise one or more materials selected from the group consisting of a transmissive organic material, such as selected from the group consisting of PE (polyethylene), PP (polypropylene), PEN (polyethylene napthalate), PC (polycarbonate), polyurethanes (PU), polymethylacrylate (PMA), polymethylmethacrylate (PMMA) (Plexiglas or Perspex), polymethacrylimide (PMI), polymethylmethacrylimide (PMMI), styrene acrylonitrile resin (SAN), cellulose acetate butyrate (CAB), silicone, polyvinylchloride (PVC), polyethylene terephthalate (PET), including in an embodiment (PETG) (glycol modified polyethylene terephthalate), PDMS (poly dimethyl siloxane), and COC (cyclo olefin copolymer). Especially, the light transmissive material may comprise an aromatic polyester, or a copolymer thereof, such as e.g. one or more of polycarbonate (PC), poly (methyl)methacrylate (P(M)MA), polyglycolide or polyglycolic acid (PGA), polylactic acid (PLA), polycaprolactone (PCL), polyethylene adipate (PEA), polyhydroxy alkanoate (PHA), polyhydroxy butyrate (PHB), poly(3-hydroxybutyrate-co-3 -hydroxy valerate) (PHBV), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN). Especially, the light transmissive material may comprise polyethylene terephthalate (PET). Hence, the light transmissive material is especially a polymeric light transmissive material.

However, in another embodiment the light transmissive material may comprise an inorganic material. Especially, the inorganic light transmissive material may be selected from the group consisting of glasses, (fused) quartz, transmissive ceramic materials, and silicones. Also hybrid materials, comprising both inorganic and organic parts may be applied. Especially, the light transmissive material comprises one or more of PMMA, transparent PC, or glass.

In embodiments, the grooves may comprise groove axes. Especially, in embodiments at least one set of two groove axes may be configured parallel but not configured coinciding. The groove axes may be a proxy for the direction along which the device light or luminescent material light may travel within the groove. Hence, configuring two grooves such that they are aligned parallel but not coinciding provides the advantage of accommodating two light guide bodies within a smaller space. That is, rather than having two grooves aligned such that the two second ends of two light guide bodies face each other, in embodiments, the two grooves may be aligned side by side. Hence, two light guide bodies may be accommodated within the light generating system such that the length of the light generating system along any direction is smaller than twice the length of the beam combiner bodies. A plurality of different arrangements can be accommodated in embodiments, such that device light or luminescent material light is provided to the central cavity from a plurality of beam combiner bodies aligned with axes parallel but not coinciding. Embodiments of such are described in the figures (see below). Another advantage of having light guide bodies not being configured opposite of each other is that it may be easier to prevent one light generating device irradiating the opposite light generating device. Nevertheless, the invention also includes embodiments wherein at least one set of two groove axes may be configured parallel and coinciding.

Further, the (each) beam combiner body may be combined with an optical element, e.g. to beam shape the system light. For instance, a collimator may be applied to create a less divergent beam of device light. In specific embodiments, the beam combiner body may be configured in an optical element, especially a hollow optical element. For instance, the beam combiner body may be configured in a hollow reflector, wherein especially a focal point of the hollow reflector may coincide with at least part of the central cavity of the beam combiner body. The optical element, such as e.g. a hollow reflector, may e.g. comprise a parabolic reflector, such as a compound parabolic reflector (CPC), or similar (hollow) reflector. Especially, the optical element is configured in a light receiving relationship with the beam combiner body.

Hence, in embodiments the light generating system may comprise a hollow reflector, wherein the beam combiner body is configured in the hollow reflector. Further, especially the hollow reflector may comprise a reflector optical axis (OR), wherein at least part of the reflector optical axis (OR) coincides with at least part of the central cavity. More especially a focal point of the hollow reflector may coincide with at least part of the central cavity of the beam combiner body. The light generating devices may be configured external of the hollow reflector. To introduce the device light into the hollow reflector, the hollow reflector may comprise (relatively small) holes in a reflector wall. The holes may be substantially smaller than an exit opening of the hollow reflector. For instance, a cross- sectional area of a hole in the reflector, indicated with Ah, may be at least 20 times, such as at least 50 times smaller than an area of the exit opening of the hollow reflector, indicated with Ao, i.e. Ah/Ao<0.05. Hence, in embodiments the hollow reflector comprises a reflector wall wherein the reflector wall may comprise at least m light injection holes configured upstream of respective light ((substantially) radially) arranged grooves and downstream of respective light generating devices.

In embodiments, the light generating system may comprise a hollow reflector. Especially, the beam combiner body may be configured in the hollow reflector. Further, in embodiments, the hollow reflector may comprise a reflector wall wherein the reflector wall may comprise at least m light injection holes configured upstream of respective light ((substantially) radially) arranged grooves and downstream of respective light generating devices. Especially, the hollow reflector may comprise a reflector optical axis (OR), wherein at least part of the reflector optical axis (OR) coincides with at least part of the central cavity. In embodiments, an optical axis of the beam combiner body may essentially coincide with a reflector optical axis (OR). In embodiments, the light generating system may comprise at least two luminescent bodies comprising at least two different luminescent materials. A primary luminescent body of the at least two luminescent bodies may be configured to convert at least part of the device light into luminescent material light having a primary spectral power distribution. Further, in embodiments, the secondary luminescent body of the at least two luminescent bodies may be configured to convert at least part of the device light into luminescent material light having a secondary spectral power distribution different from the primary spectral power distribution.

In specific embodiments, in the case of different spectral power distributions, at least two spectral power distributions of the device light (in at least two respective operational modes) may have centroid wavelengths differing at least 10 nm, such as at least 20 nm, or even at least 30 nm, such as a difference selected from the range of 30-200 nm. Spectral power distributions having centroid wavelengths differing at least 10 nm, such as at least 20 nm, or even at least 30 nm may be considered different spectral power distributions, e.g. different colors.

In (other) embodiments, two or more of the k light generating devices may be configured to generate device light with essentially the same spectral power distributions. In embodiments, at least one of the at least two different luminescent materials may comprise 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.

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 luminescent material comprises (Yi-_xLu_x)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- _xLu_x)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 sAhOn. Ce in garnets is substantially or only in the trivalent state, as is known to the person skilled in the art.

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

In specific embodiments the luminescent material comprises (Y_XI-_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.

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 (in combination with the first light source light and the second light source light (and the optical filter)). Hence, in specific embodiments A may be selected from the group consisting of Lu and Gd. Alternatively or additionally, B may comprise Ga. Hence, in embodiments the luminescent material comprises (Yxi-x2-x3(Lu,Gd)x2Cex3)3(Alyi-y2Ga_y2)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-xsCexs^ALOn, wherein xl+x3=l, and wherein 0<x3<0.2, such as 0.001-0.1.

In specific embodiments, the light generating device may only include luminescent materials selected from the type of cerium comprising garnets. In even further specific embodiments, the light generating device includes a single type of luminescent materials, such as (Yxi-x2-x3A’x2Cex3)3(Al_yi-y2B’y2)5Oi2. Hence, in specific embodiments the light generating device comprises luminescent material, wherein at least 85 weight%, even more especially at least about 90 wt.%, such as yet even more especially at least about 95 weight % of the luminescent material comprises (¥_xi-_X2-x3A’_X2Ce_X3)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.

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

However, other luminescent materials may also be possible.

Alternatively or additionally, wherein 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.

In embodiments, the luminescent material may alternatively or additionally comprise one or more of LSisNs Eu² and/or MAlSiNvEu² and/or Ca2AlSi3O2Ns:Eu²⁺, etc., wherein M comprises one or more of Ba, Sr, and Ca, especially in embodiments at least Sr. Hence, in embodiments, the luminescent may comprise one or more materials selected from the group consisting of (Ba,Sr,Ca)S:Eu, (Ba,Sr,Ca)AlSiN3:Eu and (Ba,Sr,Ca)2SisN8:Eu. In these compounds, europium (Eu) is substantially or only divalent, and replaces one or more of the indicated divalent cations. In general, Eu will not be present in amounts larger than 10% of the cation; its presence will especially be in the range of about 0.5 to 10%, more especially in the range of about 0.5 to 5% relative to the cation(s) it replaces. The term “:Eu”, indicates that part of the metal ions is replaced by Eu (in these examples by Eu²⁺). For instance, assuming 2% Eu in CaAlSi Eu, the correct formula could be (Cao.98Euo.o2)AlSiN3. Divalent europium will in general replace divalent cations, such as the above divalent alkaline earth cations, especially Ca, Sr, or Ba. The material (Ba,Sr,Ca)S:Eu can also be indicated as MS:Eu, wherein M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca); especially, M comprises in this compound calcium or strontium, or calcium and strontium, more especially calcium. Here, Eu is introduced and replaces at least part of M (i.e. one or more of Ba, Sr, and Ca). Further, the material (Ba,Sr,Ca)2SisN8:Eu can also be indicated as NESis Eu, wherein M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca); especially, M comprises in this compound Sr and/or Ba. In a further specific embodiment, M consists of Sr and/or Ba (not considering 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.sSisNs 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.

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.

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 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 considering 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.

Blue luminescent materials may comprise YSO (Y2SiOs:Ce³⁺), or similar compounds, or BAM (BaMgAlioOi?:Eu²⁺), or similar compounds. A few other examples of luminescent materials used in embodiments is discussed further below.

Hence, in a specific embodiment, the light generating system may comprise at least two luminescent bodies comprising at least two different luminescent materials, wherein a primary luminescent bodies of the at least two luminescent bodies is configured to convert at least part of the device light into luminescent material light having a primary spectral power distribution, wherein a secondary luminescent bodies of the at least two luminescent bodies is configured to convert at least part of the device light into luminescent material light having a secondary spectral power distribution different from the primary spectral power distribution; wherein at least one of the at least two different luminescent materials 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. In embodiments, two luminescent body may comprise different luminescent material type AsBsO Ce.

The light generating devices may be controlled by a control system. Hence, in embodiments the system may further comprise a control system, wherein the control system is configured to control the light generating devices. In specific embodiments, in an operational mode of the light generating system, the light generating system may be configured to generate white system light. Especially, in an operational mode the system light may comprise at least device light and luminescent material light.

Hence in a specific embodiments, the light generating system may further comprising a control system, wherein the control system is configured to control the light generating devices, wherein in an operational mode of the light generating system, the light generating system is configured to generate white system light, wherein the system light comprises at least device light and luminescent material light.

In embodiments, the control system may be configured to individually control the light generating devices. In yet other embodiments, the control system may be configured to individually control sets of light generating devices, wherein each set comprise one or more light generating devices, and wherein there are at least two sets. In yet a further aspect, the invention also provides a lamp or a luminaire comprising the light generating system as defined herein. The luminaire may further comprise a housing, optical elements, louvres, etc. etc... The lamp or luminaire may further comprise a housing enclosing the light generating system. The lamp or luminaire may comprise a light window in the housing or a housing opening, through which the system light may escape from the housing. In yet a further aspect, the invention also provides a projection device comprising the light generating system as defined herein. Especially, a projection device or “projector” or “image projector” may be an optical device that projects an image (or moving images) onto a surface, such as e.g. a projection screen. The projection device may include one or more light generating systems such as described herein. Hence, in an aspect the invention also provides a lighting device selected from the group of a lamp, a luminaire, a projector device, a disinfection device, a photochemical reactor, and an optical wireless communication device, comprising the light generating system as defined herein. The lighting device may comprise a housing or a carrier, configured to house or support, one or more elements of the light generating system. For instance, in embodiments the lighting device may comprise a housing or a carrier, configured to house or support one or more of the lighting devices and the beam combiner body. The lighting device may in embodiments be a package. Hence, in a specific embodiment, the invention may provide a lighting device selected from the group of a lamp, a luminaire, a projector device, a disinfection device, a photochemical reactor, and an optical wireless communication device, comprising the light generating system.

Below some further embodiments are described.

As mentioned above (see further above), the light source many comprise one or more light sources. In a specific embodiment, the light source comprises a solid state LED light source (such as a LED or laser diode (or “diode laser”)). The term “light source” may also relate to a plurality of light sources, such as 2-200 (solid state) LED light sources. Hence, the term LED may also refer to a plurality of LEDs. Further, the term “light source” may in embodiments also refer to a so-called chips-on-board (COB) light source. The term “COB” especially refers to LED chips in the form of a semiconductor chip that is neither encased nor connected but directly mounted onto a substrate, such as a PCB. Hence, a plurality of light emitting semiconductor light source may be configured on the same substrate. In embodiments, a COB is a multi LED chip configured together as a single lighting module. The light source may have a light escape surface. Referring to conventional light sources such as light bulbs or fluorescent lamps, it may be outer surface of the glass or quartz envelope. For LED’s it may for instance be the LED die, or when a resin is applied to the LED die, the outer surface of the resin. In principle, it may also be the terminal end of a fiber. The term escape surface especially relates to that part of the light source, where the light actually leaves or escapes from the light source. The light source is configured to provide a beam of light. This beam of light (thus) escapes from the light exit surface of the light source.

Likewise, a light generating device may comprise a light escape surface, such as an end window. Further, likewise a light generating system may comprise a light escape surface, such as an end window.

The term “light source” may refer to a semiconductor light-emitting device, such as a light emitting diode (LEDs), a resonant cavity light emitting diode (RCLED), a vertical cavity laser diode (VCSELs), an edge emitting laser, etc... The term “light source” may also refer to an organic light-emitting diode (OLED), such as a passive-matrix (PMOLED) or an active-matrix (AMOLED). As mentioned previously, in a specific embodiment, the light source comprises a solid-state light source (such as a LED or laser diode). In an embodiment, the light source comprises a LED (light emitting diode). The terms “light source” or “solid state light source” may also refer to a superluminescent diode (SLED).

The term LED may also refer to a plurality of LEDs. Further, the term “light source” may in embodiments also refer to a so-called chips-on-board (COB) light source. The term “COB” especially refers to LED chips in the form of a semiconductor chip that is neither encased nor connected but directly mounted onto a substrate, such as a PCB. Hence, a plurality of semiconductor light sources may be configured on the same substrate. In embodiments, a COB is a multi-LED chip configured together as a single lighting module.

The term “light source” may also 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 a 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 a LED with on-chip optics. In embodiments, the light source comprises a pixelated single LEDs (with or without optics) (offering in embodiments on-chip beam steering). The term “white light” herein, is known to the person skilled in the art. It especially relates to light having a correlated color temperature (CCT) between about 1800 K and 20000 K, such as between 2000 and 20000 K, especially 2700-20000 K, for general lighting especially in the range of about 2700 K and 6500 K. In embodiments, for backlighting purposes the correlated color temperature (CCT) may especially be in the range of about 7000 K and 20000 K. Yet further, in embodiments the correlated color temperature (CCT) is especially within about 15 SDCM (standard deviation of color matching) from the BBL (black body locus), especially within about 10 SDCM from the BBL, even more especially within about 5 SDCM from the BBL.

In embodiments, the term “light source” may also refer to a combination of a light source, like a LED, and an optical filter, which may change the spectral power distribution of the light generated by the light source. Especially, the “term light generating device” may be used to address a light source and further (optical components), like an optical filter and/or a beam shaping element, etc.

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

As mentioned before, the term “light source” herein may also refer to a light source comprising a solid state light source, such as an LED or a laser diode or a superluminescent diode.

The term “solid state light source”, or “solid state material light source”, and similar terms, may especially refer to semiconductor light sources, such as a light emitting diode (LED), a laser diode, or a superluminescent diode.

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 a LED, while having a brightness in the order of a laser diode.

US2020192017 indicates for instance that “With current technology, a single SLED is capable of emitting over a bandwidth of, for example, at most 50-70 nm in the 800- 900 nm wavelength range with sufficient spectral flatness and sufficient output power. In the visible range used for display applications, i.e. in the 450-650 nm wavelength range, a single SLED is capable of emitting over bandwidth of at most 10-30 nm with current technology. Those emission bandwidths are too small for a display or projector application which requires red (640 nm), green (520 nm) and blue (450 nm), i.e. RGB, emission". Further, superluminescent diodes are amongst others described, in “Edge Emitting Laser Diodes and Superluminescent Diodes”, Szymon Stanczyk, Anna Kafar, Dario Schiavon, Stephen Naj da, Thomas Slight, Piotr Perlin, Book Editor(s): Fabrizio Roccaforte, Mike Leszczynski, First published: 03 August 2020 https://doi.org/10.1002/9783527825264.ch9 in chapter 9,3 superluminescent diodes. This book, and especially chapter 9.3, are herein incorporated by reference. Amongst others, it is indicated therein that the superluminescent diode (SLD) is an emitter, which combines the features of laser diodes and light-emitting diodes. SLD emitters utilize the stimulated emission, which means that these devices operate at current densities similar to those of laser diodes. The main difference between LDs and SLDs is that in the latter case, the device waveguide may be designed in a special way preventing the formation of a standing wave and lasing. Still, the presence of the waveguide ensures the emission of a high-quality light beam with high spatial coherence of the light, but the light is characterized by low time coherence at the same time” and “Currently, the most successful designs of nitride SLD are bent, curved, or tilted waveguide geometries as well as tilted facet geometries, whereas in all cases, the front end of the waveguide meets the device facet in an inclined way, as shown in Figure 9.10. The inclined waveguide suppresses the reflection of light from the facet to the waveguide by directing it outside to the lossy unpumped area of the device chip". Hence, 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 lightemitting 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. Especially, with varying electrical current, the spectral power distribution of the superluminescent diode may vary. In this way the spectral power distribution can be controlled, see e.g. also Abdullah A. Alatawi, et al., Optics Express Vol. 26, Issue 20, pp. 26355-26364, htps://doi.org/10.1364/QE.26.026355.

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

Hence, in embodiments the light source comprises a laser light source. In embodiments, the terms “laser” or “solid state laser” or “solid state material laser” may refer to one or more of cerium doped lithium strontium (or calcium) aluminum fluoride (Ce:LiSAF, Ce:LiCAF), chromium doped chrysoberyl (alexandrite) laser, chromium ZnSe (CrZnSe) laser, divalent samarium doped calcium fluoride (Sm:CaF2) laser, Er:YAG laser, erbium doped and erbium-ytterbium codoped glass lasers, F-Center laser, holmium YAG (Ho: YAG) laser, Nd:YAG laser, NdCrYAG laser, neodymium doped yttrium calcium oxoborate Nd:YCa4O(BO3)3 or Nd:YCOB, neodymium doped yttrium orthovanadate (Nd:YVO4) laser, neodymium glass (Nd:glass) laser, neodymium YLF (Nd:YLF) solid-state laser, promethium 147 doped phosphate glass (147Pm³⁺:glass) solid-state laser, ruby laser (AhO3:Cr³⁺), thulium YAG (Tm:YAG) laser, titanium sapphire (Ti:sapphire; AhCEHi³ ) laser, trival ent uranium doped calcium fluoride (U:CaF2) solid-state laser, Ytterbium doped glass laser (rod, plate/chip, and fiber), Ytterbium YAG (Yb:YAG) laser, Yb2O3 (glass or ceramics) laser, etc.

For instance, including second and third harmonic generation embodiments, the light source may comprise one or more of an F center laser, an yttrium orthovanadate (Nd:YVO4) laser, a promethium 147 doped phosphate glass (147Pm³⁺:glass), and a titanium sapphire (Ti:sapphire; AhO3:Ti³⁺) laser. For instance, considering second and third harmonic generation, such light sources may be used to generated blue light.

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

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

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

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

The laser light source light may in embodiments comprise one or more bands, having band widths as known for lasers. In specific embodiments, the band(s) may be relatively sharp line(s), such as having full width half maximum (FWHM) in the range of less than 20 nm at RT, such as equal to or less than 10 nm. Hence, the light source light has a spectral power distribution (intensity on an energy scale as function of the wavelength) which may comprise one or more (narrow) bands.

The beams (of light source light) may be focused or collimated beams of (laser) light source light. The term “focused” may especially refer to converging to a small spot. This small spot may be at the discrete converter region, or (slightly) upstream thereof or (slightly) downstream thereof. Especially, focusing and/or collimation may be such that the cross-sectional shape (perpendicular to the optical axis) of the beam at the discrete converter region (at the side face) is essentially not larger than the cross-section shape (perpendicular to the optical axis) of the discrete converter region (where the light source light irradiates the discrete converter region). Focusing may be executed with one or more optics, like (focusing) lenses. Especially, two lenses may be applied to focus the laser light source light. Collimation may be executed with one or more (other) optics, like collimation elements, such as lenses and/or parabolic mirrors. In embodiments, the beam of (laser) light source light may be relatively highly collimated, such as in embodiments <2° (FWHM), more especially <1° (FWHM), most especially <0.5° (FWHM). Hence, <2° (FWHM) may be considered (highly) collimated light source light. Optics may be used to provide (high) collimation (see also above). The term “solid state material laser”, and similar terms, may refer to a solid state laser like based on a crystalline or glass body dopes with ions, like transition metal ions and/or lanthanide ions, to a fiber laser, to a photonic crystal laser, to a semiconductor laser, such as e.g. a vertical cavity surface-emitting laser (VCSEL), etc.

The term “solid state light source”, and similar terms, may especially refer to semiconductor light sources, such as a light emitting diode (LED), a laser diode, or a superluminescent diode.

In embodiments, the “luminescent material” may especially refer to a material that can convert radiation into e.g. visible and/or infrared light. For instance, in embodiments the luminescent material may be able to convert one or more of UV radiation and blue radiation, into visible light. The luminescent material may in specific embodiments also convert radiation into infrared radiation (IR). Hence, upon excitation with radiation, the luminescent material emits radiation. In general, the luminescent material will be a down converter, i.e. radiation of a smaller wavelength is converted into radiation with a larger wavelength (Xex<Xem), though in specific embodiments the luminescent material may comprise up-converter luminescent material, i.e. radiation of a larger wavelength is converted into radiation with a smaller wavelength ( x> m).

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

The term “luminescent material” may also refer to a plurality of different luminescent materials. Examples of possible luminescent materials are indicated below. Hence, the term “luminescent material” may in specific embodiments also refer to a luminescent material composition.

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.

The term “luminescent material” herein especially relates to inorganic luminescent materials.

Instead of the term “luminescent material” also the term “phosphor”. These terms are known to the person skilled in the art. Alternatively or additionally, also other luminescent materials may be applied. For instance quantum dots and/or organic dyes may be applied and may optionally be embedded in transmissive matrices like e.g. polymers, like PMMA, or polysiloxanes, etc. etc.

Organic phosphors can be used as well. Examples of suitable organic phosphor materials are organic luminescent materials based on perylene derivatives, for example compounds sold under the name Lumogen® by BASF. Examples of suitable compounds include, but are not limited to, Lumogen® Red F305, Lumogen® Orange F240, Lumogen® Yellow F083, and Lumogen® F170.

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

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

The luminescent material light may especially have one or more wavelengths in the visible. More especially, the centroid wavelength of the luminescent material light may be in the visible.

In specific embodiments, the luminescent material may be configured to convert part of the light source light into luminescent material light having a wavelength in the 495-605 nm. In specific embodiments, a substantial part, like at least 85%, like at least 90%, more especially at least 95%, such as (essentially) 100% of the spectral power of the system light may be in the 495-605 nm wavelength range. In embodiments the centroid wavelength may be configured in the 495-605 nm wavelength range. More especially, the centroid wavelength may be configured in the 510-590 nm wavelength range, even more especially in the 570-590 nm wavelength range. Hence, in specific embodiments the light source light may be blue light and the luminescent material light may be yellow light or may comprise a combination of yellow and red light.

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

The term “controlling” and similar terms especially refer at least to determining the behavior or supervising the running of an element. Hence, herein “controlling” and similar terms may e.g. refer to imposing behavior to the element (determining the behavior or supervising the running of an element), etc., such as e.g. measuring, displaying, actuating, opening, shifting, changing temperature, etc.. Beyond that, the term “controlling” and similar terms may additionally include monitoring. Hence, the term “controlling” and similar terms may include imposing behavior on an element and also imposing behavior on an element and monitoring the element. The controlling of the element can be done with a control system, which may also be indicated as “controller”. The control system and the element may thus at least temporarily, or permanently, functionally be coupled. The element may comprise the control system. In embodiments, the control system and element may not be physically coupled. Control can be done via wired and/or wireless control. The term “control system” may also refer to a plurality of different control systems, which especially are functionally coupled, and of which e.g. one control system may be a master control system and one or more others may be slave control systems. A control system may comprise or may be functionally coupled to a user interface.

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

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

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

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

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

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

The terms “visible”, “visible light” or “visible emission” and similar terms refer to light having one or more wavelengths in the range of about 380-780 nm. Herein, UV may especially refer to a wavelength selected from the range of 190-380 nm, such as 200-380 nm. The terms “light” and “radiation” are herein interchangeably used, unless clear from the context that the term “light” only refers to visible light. The terms “light” and “radiation” may thus refer to UV radiation, visible light, and IR radiation. In specific embodiments, especially for lighting applications, the terms “light” and “radiation” refer to (at least) visible light.

The terms “violet light” or “violet emission” 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 term “pink light” or “pink emission” refers to light having a blue and a red component. The term “cyan” may refer to one or more wavelengths selected from the range of about 490-520 nm. The term “amber” may refer to one or more wavelengths selected from the range of about 585-605 nm, such as about 590-600 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.

The terms “upstream” and “downstream”, such as in the context of propagation of light, may especially relate to an arrangement of items or features relative to the propagation of the light from a light generating element (here the especially the first light source), wherein relative to a first position within a beam of light from the light generating element, a second position in the beam of light closer to the light generating element (than the first position) is “upstream”, and a third position within the beam of light further away from the light generating element (than the first position) is “downstream”. For instance, instead of the term “light generating element” also the term “light generating means” may be applied. BRIEF DESCRIPTION OF THE DRAWINGS

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

Fig. 1 schematically depicts in embodiments I and II, two cross-sectional views of the light generating system.

Fig. 2 schematically depicts embodiments of the light generating system comprising a hollow reflector.

Fig. 3a-b depict top views of two embodiments of the light generating system.

Fig. 4 schematically depicts an embodiment of the light generating system comprising a second optical body.

Fig. 5 schematically depict some application embodiments. The schematic drawings are not necessarily to scale.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Fig. 1 schematically depicts in embodiments I and II two cross-sectional views of essentially the same beam combiner body 500, but with different configurations of the k arrangements 1050. In embodiments, the invention may provide a light generating system 1000 comprising (i) a beam combiner body 500, and (ii) k arrangements 1050.

The beam combiner body 500 may, in embodiments, comprise a first face 501, wherein the first face 501 comprises n ((substantially) radially) arranged grooves 510 ((substantially) radially) extending from a central cavity 520. Especially, n>2. The cross- sectional view depicts embodiments I and II where at least 2 such arrangements are shown. Further, in embodiments, the n grooves 510 may have a first end 513 and a second end 514. Especially, the first end 513 may be configured more remote from the central cavity 520 than the second end 514, and wherein the second end 514 may end up in the central cavity.

In embodiments, each of the k arrangements 1050 may comprise a light generating device 100, a luminescent body 210, a first optical element 551, and a light guide body 530. Especially, 2<k<n.

In embodiments, the light generating device 100 may be configured to generate device light 101. Especially, the light generating device 100 may comprise one or more light sources selected from the group of lasers and superluminescent diodes. In embodiments, the luminescent body 210 may comprise a luminescent material 200 configured to convert at least part of the device light 101 into luminescent material light 201. Further, in embodiments, the first optical element 551 may comprise one or more of a beam shaping element and a lens. In embodiments, the light guide body 530 may be configured in one of the grooves 510. Especially, the light guide body 530 may be light transmissive for the luminescent material light 201. Further, the light guide body 530 may have a first body end 531 and a second body end 532, wherein the first body end 531 may be configured more remote from the central cavity 520 than the second body end 532. Light may essentially enter the groove via the first body end 531 and hence, the face of the first body end may (also) be referred to as the primary face. Likewise, light may escape from the second body end 532 and hence, the face of the second body end may (also) be referred to as the secondary face. Alternatively, the face of the luminescent body 210 or the first optical element 551 via which light may enter the groove 510 may further (also) be referred to as the primary face.

In embodiments, the luminescent body 210 may be configured downstream of the light generating device 100. Especially, the first optical element 551 may be configured downstream of the luminescent body 210, and the first body end 531 of the light guide body 530 may be configured downstream of the first optical element 551.

In embodiments, at least one of the following may apply: (i) the second body end 532 is at least partly configured in the central cavity 520, and the second body end 532 is slanted (depicted in embodiment II), and (ii) the central cavity 520 has a slanted reflective face 521 (depicted in embodiment I). Especially, the second body end 532 may have a first angle (al) with a groove axis 511 of the groove 510 wherein the light guide body 530 is configured. In embodiments, the first angle (al) may be selected from the range of 15-75°, or the slanted reflective face 521 of the central cavity may have a second angle (a2) with a groove axis 511 of an oppositely configured groove 510, wherein the second angle (a2) may be selected from the range of 15-75°. Further, in embodiments, the first optical element 551 may comprise a collimator element. Yet further, in embodiments, the light generating device 100 may at least comprise one or more laser diodes.

In embodiments, the light generating device 100 may at least be partly configured within one of the grooves 510 and may be configured in direct or indirect thermal contact with the beam combiner body 500. Further, in embodiments, the luminescent body 210 may at least be partly configured within one of the grooves 510 and may be configured in direct or indirect thermal contact with the beam combiner body 500. Further, in embodiments, the first optical element 551 may at least be partly configured within one of the grooves 510 and may be configured in direct or indirect thermal contact with the beam combiner body 500. In embodiments, the beam combiner body 500 may comprise a thermally conductive body. Especially, the grooves 510 may comprise groove surfaces 512, wherein the groove surfaces 512 may comprise a material reflective for the luminescent material light 201.

In embodiments, the first optical element 551 may have a first index of refraction nl, and the light guide body 530 may have a second index of refraction n2, wherein 1.4<n2-nl< 1.8. Especially, the first optical element 551 and the light guide body 530 may comprise the same material. More especially, the light guide body 530 may comprise a glass, quartz, a ceramic body, or a polymeric material.

In embodiments, the light generating system may comprise at least two luminescent bodies 210 comprising at least two different luminescent materials 200. Especially, a primary luminescent bodies 210 of the at least two luminescent bodies 210 may be configured to convert at least part of the device light 101 into luminescent material light 201 having a primary spectral power distribution. Especially, one or more secondary luminescent bodies 210 of the at least two luminescent bodies 210 may be configured to convert at least part of the device light 101 into luminescent material light 201 having a secondary spectral power distribution different from the primary spectral power distribution. In embodiments, at least one of the at least two different luminescent materials 200 may comprise 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.

In embodiments, the light generating system 1000 may further comprise a control system 300. Especially, the control system 300 may be configured to control the light generating devices 100, wherein in an operational mode of the light generating system 1000, the light generating system 1000 may be configured to generate white system light 1001. In embodiments, the system light may comprise at least device light 101 and luminescent material light 201.

Referring to Fig. 2, the light generating system 1000 may comprise an optical element 610, such as a hollow reflector. The beam combiner body 500 may be configured in the optical element 610, such as a hollow reflector. The hollow reflector may comprise a reflector wall 611. The reflector wall 611 may comprise at least m light injection holes 612 configured upstream of respective light ((substantially) radially) arranged grooves 510 and downstream of respective light generating devices 100. The optical element 610, such as a hollow reflector may comprise a reflector optical axis OR. At least part of the reflector optical axis OR coincides with at least part of the central cavity 520. In embodiments, the light generating device 100 may be configured outside the hollow reflector 610. In (such) embodiments, the beam combiner body 500 may be positioned inside the hollow reflector 610. Especially, the lens 120 may be used to focus the device light 101. More especially, the device light 101 may be provided to the beam combiner body 500 via the light injection holes 612. The figure on the left depicts an embodiment, wherein the light generating device is configured along the axis of the groove. The figure on the right depicts an embodiment, wherein the light generating device is configured perpendicular to the axis of the groove.

The n ((substantially) radially) arranged grooves 510 may have rectangular cross-sections (perpendicular to respective groove axes 511).

Fig. 3a and Fig. 3b depict the top view of two embodiments of the light generating system. The beam combiner body 500 may, in embodiments, comprises a first face 501, wherein the first face 501 comprises n ((substantially) radially) arranged grooves 510 ((substantially) radially) extending from a central cavity 520. Especially, n>2. In the embodiment depicted, the light generating system comprises 4 such grooves. Further, in embodiments, the n grooves 510 may have a first end 513 and a second end 514. Especially, the first end 513 may be configured more remote from the central cavity 520 than the second end 514, and wherein the second end 514 may end up in the central cavity.

In embodiments, the light generating system may comprise k arrangements. Especially, each of the k arrangements 1050 may comprise a light generating device 100, a luminescent body 210, a first optical element 551, and a light guide body 530. Especially, 2<k<n. In the embodiment depicted, the light generating system comprises 3 such arrangements. The central cavity may comprise a wall, wherein the second ends are openings. However, with larger number of grooves the second ends may be adjacent to each other without any intermediate wall parts 537.

Fig. 3b depicts an embodiment of the light generating system comprising 4 grooves, further comprising 4 arrangements. In embodiments, at least one set of two groove axes 511 may be configured parallel but not configured coinciding. In the embodiment depicted, there are two sets of grooves that are parallel but not coinciding.

Referring to the embodiment schematically depicted in Fig. 3b, the first face 501 may comprise n substantially radially arranged grooves 510 substantially radially extending from the central cavity 520. Referring to the embodiment schematically depicted in Fig. 3a, the first face 501 may comprise n radially arranged grooves 510 radially extending from a central cavity 520.

Fig. 4 depicts an embodiment of the light generating system comprising a second optical body 570. Especially, the second optical body 570 may be a dome-shaped optical body. In embodiments, the second optical body 570 may at least be partly extending from the central cavity 520. Especially, the second optical body 570 may be configured downstream of the light guide bodies 530. Further, in embodiments, the light guide body 530 may have a second index of refraction n2, wherein the second optical body 570 may have a third index of refraction n3. Especially, 0 <n3-n2<0.4. In embodiments, the light guide bodies 530 and the second optical body 570 may be a monolithic body. Such an embodiment provides the advantage that the hollow reflector 610 may be configured without light injection holes 612, especially, since the second optical body 570 may be configured above the grooves 510 and within the hollow reflector 610. Therefore, in embodiments, the hollow reflector 610 may (also) be configured above the one or more grooves 510.

In embodiments, the second optical body 570 may be configured essentially on top of the (end part) of the one or more grooves 510. Hence, in such an embodiment, the hollow reflector 610 may also be configured substantially on top of the one or more grooves 510.

Note that Fig. 4 schematically depicts an embodiment wherein both a second optical body 570 and a hollow 610 reflector is shown. However, herein the invention is also directed to systems 1000 comprising such second optical body 570 but not comprising such hollow reflector 610, as well as systems 1000 not comprising such second optical body 570 but comprising such hollow reflector 610.

Especially, the optical body 570 may be configured to beamshape the luminescent material light 201 received by the optical body 570 from the light guide body 530 and/or to extract the luminescent material light 210 from the light guide body 530.

Fig. 5 schematically depicts an embodiment of a luminaire 2 comprising the light generating system 1000 as described above. Reference 301 indicates a user interface which may be functionally coupled with the control system 300 comprised by or functionally coupled to the light generating system 1000. Fig. 3 also schematically depicts an embodiment of lamp 1 comprising the light generating system 1000. Reference 3 indicates a projector device or projector system, which may be used to project images, such as at a wall, which may also comprise the light generating system 1000. Hence, Fig. 3 schematically depicts embodiments of a lighting device 1200 selected from the group of a lamp 1, a luminaire 2, a projector device 3, a disinfection device, a photochemical reactor, and an optical wireless communication device, comprising the light generating system 1000 as described herein. In embodiments, such lighting device may be a lamp 1, a luminaire 2, a projector device 3, a disinfection device, 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.

The term “plurality” refers to two or more.

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

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

The term “and/or” especially relates to one or more of the items mentioned before and after “and/or”. For instance, a phrase “item 1 and/or item 2” and similar phrases may relate to one or more of item 1 and item 2. The term "comprising" may in an embodiment refer to "consisting of but may in another embodiment also refer to "containing at least the defined species and optionally one or more other species".

Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

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

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

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

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

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

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

The invention also provides a control system that may control the device, apparatus, or system, or that may execute the herein described method or process. Yet further, the invention also provides a computer program product, when running on a computer which is functionally coupled to or comprised by the device, apparatus, or system, controls one or more controllable elements of such device, apparatus, or system.

The invention further applies to a device, apparatus, or system comprising one or more of the characterizing features described in the description and/or shown in the attached drawings. The invention further pertains to a method or process comprising one or more of the characterizing features described in the description and/or shown in the attached drawings.

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

In embodiments, holes in a reflector cup may be used as part of the optical path to address the luminescent material comprising first bodies in the beam combiner body. These holes may provide a path at the bottom of the reflector cup to have a laser beam enter the inner space of the reflector cup and may address the mounted luminescent material comprising first bodies in the center of, or around the optical axis of the reflector cup. With this optical solution the lasers can be placed in the same plane as the luminescent material comprising first bodies. The benefit may be a compact assembly for lasers and luminescent material comprising first bodies without additional beam splitters or beam concentrators. The holes can be divided over the circumference of the reflector cup, there where they will be aligned with the radial positioned rectangle grooves on the beam combiner body pointing to the center of the disc.

In embodiments, the number of grooves can be selected from 1 to 100, but especially at least 2. With the note that adding more than three grooves to the radial, the intermediate distance of the grooves to the center of the disc becomes larger, which may have impact on the etendue of the optical system.

As mentioned the grooves may especially be used to mount luminescent material comprising first bodies in. The luminescent material comprising first bodies may be attached to a rectangle rod which has the size of the rectangle groove of the beam combiner body. The rectangle rod can be of a metal when used in the reflective mode or of a sapphire when used in the translucent. In both set up the rods can be glued or soldered in the grooves of the beam combiner body. With the close fitting of the luminescent material comprising first body rod in the grooves, a high thermal contact may be reached.

Making use of the beam combiner body allows combinations of luminescent material comprising first bodies with different CCT in a simple plane at the center of the optic axis. There may substantially be no need for additional optics like beam splitters or dichroic mirrors to have two or more different luminescent material comprising first bodies centered in the optical path.

With this approach two or more lasers may address two or more luminescent material comprising first bodies with different CCT. While the light emitting surface is already placed in the reflector cup. There is a minimal need for additional optics to guide and mix the light in the reflector.

By tuning the power of the lasers, different color temperatures can be obtained.

Adding a red phosphor luminescent material comprising first body to the light source a high CRI can be obtained.

Also direct red, green, or blue lasers can be installed and where in the phosphor option luminescent material comprising first bodies where installed there are now (diffused) mirrors placed to guide the individual lasers.

In an embodiment, luminescent material comprising first body may be glued with a transparent dye attach material on a sapphire rectangle rod. The sapphire rod may act as a light guide and at the same time as a thermal conductor to take away the heat from the luminescent material comprising first body. The luminescent material comprising first body - rod assembly may be clamped or glued to the heatsink of the beam combiner body. The luminescent material comprising first body may be positioned in the center of the optical path of the beam combiner body. In operation the laser points to the back end of the sapphire rod where it enters. By total internal reflection (TIR) the laser addresses the luminescent material comprising first body surface. Light is emitted towards the reflector. Mounting a second luminescent material comprising first body with a different CCT on a second sapphire rod and placing that on the opposite direction of the first Luminescent material comprising first body assembly will apply for a tunable CCT of the Light module. As said a multiple number of luminescent material comprising first body assemblies can be placed on the heatsink of the light module where combinations of different CCT and Red phosphors for adjusting CRI is possible. An advantage of the translucent mode assembly is that the laser beam addresses the luminescent material comprising first body from the back side. This means that there may be more space available in the beam combiner body on the diameter of the assembly to mount individual lasers and thus also luminescent material comprising first bodies. A disadvantage may be a less efficient cooling of the luminescent material comprising first body through the sapphire rod.

In another embodiment, a luminescent material comprising first body may be glued or soldered on a metal rectangle rod and subsequently attached on the beam combiner body. Where the position of the luminescent material comprising first body is in the center of the optical path. In this mode the laser may be positioned opposite of the position of the luminescent material comprising first body and directly hit the luminescent material comprising first body on the front side. Light is emitted in the reflective mode. The thermal load of the luminescent material comprising first body may instantly be directed to the beam combiner body acting as heat sink. Where in the translucent mode a sapphire rod may be used, the reflective mode may make use of a copper rod insert to glue the luminescent material comprising first body on. An advantage of the reflective mode assembly may be a better thermal behavior of the luminescent material comprising first body. The luminescent material comprising first body can be plated with a metal coating on its back side what allows the luminescent material comprising first body to be soldered on the heatsink, which improves the thermal behavior even more. Soldering may increase the thermal conductivity, typical 50-70Wm/K for solder and 0.2 -04 Wm/K for dye attach epoxy materials. Next to a better thermal behavior also light efficiency is increased. The heat sink can be plated with a reflector coating which makes the light extraction from the luminescent material comprising first body more efficient. A disadvantage of the reflective mode is that the laser beam which addresses a luminescent material comprising first body occupies space opposite of the luminescent material comprising first body. Half of the amount of laser / luminescent material comprising first bodies can be placed on the available space in the light module.

A more direct approach may be to place the laser diode on a radial distance from the axial axe of the light module, where the TO can may be placed in line with the radial axe. This design method places the laser beam direct in line with the luminescent material comprising first body. Here the laser beam also punches through the reflector cup via small holes. With this design a thin module may be possible.

In transmissive mode where a sapphire rod is used, the rod may have the same size as the first body. Otherwise (blue) light from the laser may be leaking next to the first body. The first body may be glued with a transparent dye attach paste to the sapphire rod.

In a reflective mode, the rod may be somewhat larger than the first body. There the first body may be glued or soldered to a metal rod.

Claims

CLAIMS:

1. A light generating system (1000) configured to generate system light (1001), comprising (i) a beam combiner body (500), and (ii) k arrangements (1050); wherein: the beam combiner body (500) comprises a first face (501), wherein the first face (501) comprises n grooves (510) extending from a central cavity (520) and the n grooves (510) being configured to provide light directed towards the central cavity (520), wherein n>2; wherein the n grooves (510) have a first end (513) and a second end (514), wherein the first end (513) is configured more remote from the central cavity (520) than the second end (514); each of the k arrangements (1050) comprises a light generating device (100), a luminescent body (210), a first optical element (551), and a light guide body (530); wherein 2<k<n; the light generating device (100) is configured to generate device light (101), wherein the light generating device (100) comprise one or more light sources selected from the group of lasers and superluminescent diodes; the luminescent body (210) comprises a luminescent material (200) configured to convert at least part of the device light (101) into luminescent material light (201); the first optical element (551) comprises one or more of a beam shaping reflective element and a lens; the light guide body (530) is configured in one of the grooves (510); wherein the light guide body (530) is light transmissive for the luminescent material light (201); wherein the light guide body (530) has a first body end (531) and a second body end (532), wherein the first body end (531) is configured more remote from the central cavity (520) than the second body end (532), and wherein the light guide body (350) is configured to propagate light to the central cavity (520) via the second body end (532); the luminescent body (210) is configured downstream of the light generating device (100); the first optical element (551) is configured downstream of the luminescent body (210); and the first body end (531) of the light guide body (530) is configured downstream of the first optical element (551); wherein the system light (1001) comprises one or more of the device light and the luminescent material light, and wherein, during operation of the light generating system (1000), the system light emanates from the central cavity (520).

2. The light generating system (1000) according to claim 1, wherein the grooves (510) are radially arranged, radially extending from the central cavity (520); wherein at least one of the following applies: (i) the second body end (532) is at least partly configured in the central cavity (520), and the second body end (532) is slanted, and (ii) the central cavity (520) has a slanted reflective face (521); wherein the first optical element (551) comprises a collimator element; and wherein the light generating device (100) at least comprise one or more laser diodes.

3. The light generating system (1000) according to any one of the preceding claims, wherein the light generating device (100) is at least partly configured within one of the grooves (510) and is configured in direct or indirect thermal contact with the beam combiner body (500).

4. The light generating system (1000) according to any one of the preceding claims, wherein the luminescent body (210) is at least partly configured within one of the grooves (510) and is configured in direct or indirect thermal contact with the beam combiner body (500).

5. The light generating system (1000) according to any one of the preceding claims, wherein the first optical element (551) is at least partly configured within one of the grooves (510) and is configured in direct or indirect thermal contact with the beam combiner body (500).

6. The light generating system (1000) according to any one of the preceding claims, wherein the beam combiner body (500) comprises a thermally conductive body; wherein grooves (510) comprise groove surfaces (512), wherein the groove surfaces (512) comprise a material reflective for the luminescent material light (201).

7. The light generating system (1000) according to any one of the preceding claims, further comprising a second optical body (570), at least partly extending from the central cavity (520), wherein the second optical body (570) is configured downstream of the light guide bodies (530).

8. The light generating system (1000) according to claim 7, wherein the light guide body (530) has a second index of refraction n2, wherein the second optical body (570) has a third index of refraction n3, wherein 0<n3-n2<0.4.

9. The light generating system (1000) according to any one of the preceding claims 7-8, and wherein the second optical body (570) is configured to beamshape the luminescent material light (201) received by the second optical body (570) from the light guide body (530) and/or to extract the luminescent material light (210) from the light guide body (530); and wherein the second optical body (570) is dome-shaped.

10. The light generating system (1000) according to any one of the preceding claims 7-9, wherein the light guide bodies (530) and the second optical body (570) are a monolithic body.

11. The light generating system (1000) according to any one of the preceding claims, wherein the grooves (510) comprise groove axes (511), wherein at least one set of two groove axes (511) are configured parallel but not configured coinciding.

12. The light generating system (1000) according to any one of the preceding claims, comprising a hollow reflector (610), wherein the beam combiner body (500) is configured in the hollow reflector (610), wherein: the hollow reflector (610) comprises a reflector wall (611) wherein the reflector wall (611) comprises at least m light injection holes (612) configured upstream of respective light grooves (510) and downstream of respective light generating devices (100); and the hollow reflector (610) comprises a reflector optical axis (OR), wherein at least part of the reflector optical axis (OR) coincides with at least part of the central cavity (520).

13. The light generating system (1000) according to any one of the preceding claims, comprising at least two luminescent bodies (210) comprising at least two different luminescent materials (200), wherein a primary luminescent bodies (210) of the at least two luminescent bodies (210) is configured to convert at least part of the device light (101) into luminescent material light (201) having a primary spectral power distribution, wherein a secondary luminescent bodies (210) of the at least two luminescent bodies (210) is configured to convert at least part of the device light (101) into luminescent material light (201) having a secondary spectral power distribution different from the primary spectral power distribution; wherein at least one of the at least two different luminescent materials (200) 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.

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 the light generating devices (100), wherein in an operational mode of the light generating system (1000), the light generating system (1000) is configured to generate white system light (1001), wherein the system light comprises at least device light (101) and luminescent material light (201).

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