High-intensity BBL dimmable light source

Abstract

The present invention provides a light-generation system 1000 comprising a first light-generating device 110, a second light-generating device 120, a third light-generating device 130, a luminescent material 200 and a control system 300, wherein (A) the first light-generating device 110 comprises a first laser light source and is configured to generate a first device light 111 having a first device peak wavelength λ1 and having a first spectral power distribution, the first device peak wavelength λ1 being selected from a wavelength range of 445 to 475 nm; (B) the second light-generating device 120 comprises a second laser light source and is configured to generate a first device light 111 having a first device peak wavelength λ1 and having a first spectral power distribution, the first device peak wavelength λ1 being selected from a wavelength range of 445 to 475 nm; (C) the luminescent material 200 is configured to generate a second device light 121 having a second spectral power distribution having a centroid wavelength λ2 different from the first spectral power distribution, the second device peak wavelength λ2 being selected from the range of 420 to 450 nm or the range of 470 to 490 nm; (D) the luminescent material 200 is excitable by the first device light 111 and the second device light 121, and the luminescent material 200 is configured to excite at least a portion of one or more of the first device light 111 and / or the second device light 121 at a centroid wavelength λ2 within a green-orange wavelength range. c,1 (D) the third light generating device 110 has a third laser light source and is configured to generate a third device light 111 having a third device peak wavelength λ3 selected from a wavelength range of 600 to 650 nm; (E) |λ1-λ2|≧20 nm, λ1 and λ2 are selected from a wavelength range of 420 to 490 nm, and |λ c,1 -λ3|≧20 nm; (F) the control system 300 is configured to control at least the first light-generating device 110 and the second light-generating device 120; and (G) the light-generating system 1000 is configured to provide white system light 1001 in an operating mode.

Description

[Technical field]

[0001] The present invention relates to a light generation system and to a lighting device comprising such a light generation system. [Background technology]

[0002] Light sources such as laser light sources are known in the art.For example, US20180316160 discloses a laser diode device including a material containing gallium and nitrogen and configured as an excitation source; a phosphor member configured as a wavelength converter and emitter and coupled to the laser diode device; a common support member configured to support the laser diode device and the phosphor member, and a heat sink thermally coupled to the common support member, the common support member configured to transfer thermal energy from the laser diode device and the phosphor member to the heat sink; an output facet configured on the laser diode device to output a laser beam comprised of electromagnetic radiation selected from violet and / or blue emissions having a first wavelength between 400 nm and 485 nm; and a non-guided characteristic capable of transmitting the laser beam from the laser diode device to an excitation surface of the phosphor member. a free space between the output facet and the phosphor member having a characteristic free space between the output facet and the phosphor member, a range of incidence angles between the laser beam and the excitation surface of the phosphor member such that, on average, the laser beam has a non-normal incidence on the excitation surface and a beam spot is configured for a certain geometric size and shape, the phosphor member converting a portion of the electromagnetic radiation from the laser beam having the first wavelength into radiated electromagnetic radiation having a second wavelength longer than the first wavelength, the integrated white light source comprising: a plurality of scattering centers associated with the phosphor member that scatter electromagnetic radiation having the first wavelength from the laser beam incident on the phosphor member; a reflection mode that characterizes the phosphor member such that the laser beam is incident on a beam spot area on the excitation surface of the phosphor member and white light radiation is output from substantially the same beam spot area, the white light radiation being composed of a mixture of wavelengths characterized by radiated electromagnetic radiation of at least the second wavelength from the phosphor member; and a form factor that characterizes a package of the integrated white light source. US Pat. No. 5,999,363 describes an integrated white light source having a form factor having dimensions of length, width and height. Summary of the Invention [Problem to be solved by the invention]

[0003] A white LED light source, for example, has a light output of approximately 300 lm / mm 2 While static phosphor-converted laser white light sources can provide intensities up to about 20,000 lm / mm 2 It can even give an intensity of up to 1000 nm. Ce-doped garnets (e.g., YAG, LuAG) may be the most suitable luminescence converters that can be used to pump with blue laser light, since the garnet host material has a very high chemical stability. Furthermore, at low Ce concentrations (e.g., less than 0.5%), temperature quenching may only occur above about 200° C. Furthermore, the emission from Ce has a very fast decay time, and therefore the occurrence of light saturation can be essentially prevented. Assuming, for example, a reflection mode operation, blue laser light may be incident on the phosphor. This may achieve, in embodiments, a nearly complete conversion of blue light, resulting in the emission of converted light. It is for this reason that the use of garnet phosphors with relatively high stability and thermal conductivity is proposed. However, other phosphors may also be applied. Thermal management may still be a challenge when very high power densities are used.

[0004] High brightness light sources can be used in applications such as projection, stage lighting, spot lighting, automotive lighting, etc. For this purpose, laser-phosphor technology can be used, where a laser provides the laser light and for example a (remote) phosphor converts the laser light into converted light. The phosphor may in embodiments be arranged on or inserted into a heat sink for improved thermal management and thus higher brightness.

[0005] One of the problems that may be associated with such (laser) light sources is the thermal management of ceramic phosphors. Another problem associated with such laser light sources may be the desire to create compact high-power devices, which may not always be relatively easy. Furthermore, when using luminescent materials, high-intensity pump light sources may cause thermal quenching of some known luminescent materials. However, when using laser diodes, for example, not all types of laser diodes are efficient.

[0006] It is therefore an aspect of the present invention to provide an alternative light-generating system, which preferably also at least partially obviates one or more of the above disadvantages. The present invention may aim to eliminate or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative. [Means for solving the problem]

[0007] According to a first aspect, the present invention provides a light-generating system ("system") comprising a first light-generating device, a second light-generating device and a luminescent material. In an embodiment, the light-generating system may further comprise a third light-generating device. In particular, the first light-generating device may comprise, in an embodiment, a semiconductor-based light source, such as a laser light source (e.g. a laser diode). In particular, the first light-generating device may be configured to generate a first device light having a first device peak wavelength (λ1). The first device light may have a first spectral power distribution. In an embodiment, the first device peak wavelength (λ1) may be selected from a wavelength range of 445 to 475 nm. Furthermore, the second light-generating device may comprise, in an embodiment, a semiconductor-based light source, such as a laser light source (e.g. a laser diode).

[0008] In particular, the second light generating device may be configured to generate a second device light having a second device peak wavelength (λ2). The second device light may have a second spectral power distribution. In an embodiment, the second device peak wavelength (λ2) may be selected from the range of 420-450 nm or the range of 470-490 nm. The first and second spectral power distributions may be different. Furthermore, in an embodiment, the luminescent material may be excitable by the first device light and the second device light. In particular, the luminescent material may be configured to convert at least a portion of one or more of the first device light and / or the second device light into luminescent material light. In an embodiment, the luminescent material light has a centroid wavelength λ2 within a green-orange wavelength range. c,1The luminescent material may have an absorbance band with a first absorbance E1 at the first device peak wavelength (λ1) and a second absorbance E2 at the second device peak wavelength (λ2). In particular embodiments, E2 / E1<1. In particular embodiments, |λ1-λ2|≧20 nm. Furthermore, in embodiments, λ1 and λ2 may be selected from the wavelength range of 420 to 490 nm. The system may further comprise a control system. In particular, the control system may be configured to control at least the first light-generating device and the second light-generating device. As mentioned above, the system may further comprise, in embodiments, a third light-generating device. In particular, the third light-generating device may (also) in embodiments comprise a semiconductor-based light source, such as a laser light source (e.g. a laser diode). In particular, the third light-generating device may be configured to generate a third device light having a third device peak wavelength (λ3). The third device light may have a third spectral power distribution. In an embodiment, the third device peak wavelength (λ3) may be selected from the wavelength range of 590 to 780 nm, more particularly 600 to 650 nm. In particular, the first spectral power distribution, the second spectral power distribution and the third spectral power distribution are different from each other. In particular, |λ c,1 −λ3|≧20 nm may apply, more particularly |λ c,1-λ3|≧30 nm may apply. Furthermore, in an embodiment, the light generating system may be configured to provide white system light in an operational mode. Thus, in a particular embodiment, the present invention relates to a light generating system comprising a first light generating device, a second light generating device, a third light generating device, a luminescent material, and a control system, wherein (A) the first light generating device comprises a first laser light source and is configured to generate first device light having a first device peak wavelength (λ1) and having a first spectral power distribution, the first device peak wavelength (λ1) being selected from a wavelength range of 445 to 475 nm, (B) the second light generating device comprises a second laser light source and is configured to generate first device light having a first device peak wavelength (λ1) and having a first spectral power distribution, the first device peak wavelength (λ1) being selected from a wavelength range of 445 to 475 nm, and (C) the luminescent material is excitable by the first device light and the second device light, and the luminescent material is configured to excite at least a portion of one or more of the first device light and / or the second device light at a centroid wavelength λ 2 within a green-orange wavelength range. c,1 (D) the third light generating device has a laser light source and is configured to generate third device light having a third device peak wavelength (λ3) selected from a wavelength range of 600 to 650 nm, (E) |λ1-λ2|≧20 nm, λ1 and λ2 are selected from a wavelength range of 420 to 490 nm, and |λ c,1 -λ3|≧30 nm; and (F) the control system is configured to control at least the first light-generating device and the second light-generating device, and the light-generating system is configured to provide white system light in an operational mode.

[0009] Such a system can provide a high intensity light producing system, can be relatively simple, and can provide white light with a color point relatively close to the blackbody locus while controlling the correlated color temperature over at least 500K, or even over about 1000K.

[0010] As mentioned above, the system may comprise a first light-generating device, a second light-generating device and, optionally, a third light-generating device.

[0011] The first light generating device ("first device") may in particular be configured to generate a first device light. In particular, the first light generating device comprises a first light source. The first light source may in particular be configured to generate a first light source light. In an embodiment, the first device light may essentially consist of the first device light. In a particular embodiment, the first light source may comprise a laser light source. Thus, in a particular embodiment, the first light source light may comprise a first laser device light. Hence, in a particular embodiment, the first device light may essentially consist of the first laser device light. Thus, as also shown below, in an embodiment, the light generating system may comprise a first laser device. The term "first laser device" may also refer to multiple first laser devices of essentially the same type, such as from the same bin.

[0012] The second light generating device ("second device") may in particular be configured to generate a second device light. In particular, the second light generating device comprises a second light source. The second light source may in particular be configured to generate a second light source light. In an embodiment, the second device light may essentially consist of the second device light. In a particular embodiment, the second light source may comprise a laser light source. Thus, in a particular embodiment, the second light source light may comprise a second laser device light. Hence, in a particular embodiment, the second device light may essentially consist of the second laser device light. Thus, as also shown below, in an embodiment, the light generating system may comprise a second laser device. The term "second laser device" may also refer to multiple, essentially the same type of second laser devices, such as those from the same bin.

[0013] The third light generating device ("third device") may in particular be configured to generate a third device light. In particular, the third light generating device comprises a third light source. The third light source may in particular be configured to generate a third light source light. In an embodiment, the third device light may essentially consist of the third device light. In a particular embodiment, the third light source may comprise a laser light source. Thus, in a particular embodiment, the third light source light may comprise a third laser device light. Hence, in a particular embodiment, the third device light may essentially consist of the third laser device light. Thus, as also shown below, in an embodiment, the light generating system may comprise a third laser device. The term "third laser device" may also refer to multiple, essentially the same type of third laser devices, such as those from the same bin.

[0014] Thus, the phrase "the system may have a first light-generating device, a second light-generating device, and a third light-generating device" and similar phrases may refer in particular to embodiments in which the system may have a first laser light source, a second laser light source, and a third laser light source.

[0015] Furthermore, the phrase "the system may have a first light-generating device, a second light-generating device, and a third light-generating device" and similar phrases may refer to embodiments in which the system may have one or more first light-generating devices, one or more second light-generating devices, and one or more third light-generating devices.

[0016] Below are provided some aspects relating to light sources, laser light sources, etc. that may be applied to one or more of the first light-generating device, the second light-generating device and (optionally) the third light-generating device.

[0017] The light-generating device may comprise one or more light sources, more particularly one or more solid-state light sources. Furthermore, the light-generating device may comprise an optical system. Light emerging from the one or more light sources, i.e. source light (from the one or more light sources), may in embodiments be beam-shaped via the optical system. The device light may in particular comprise the source light. More particularly, the device light may essentially consist of the (source) light of the one or more light sources.

[0018] The term "light source" may in principle relate to any light source known in the art. It may be a conventional (tungsten) light bulb, a low-pressure mercury lamp, a high-pressure mercury lamp, a fluorescent lamp, an LED (light-emitting diode). In a particular embodiment, the light source comprises a solid-state LED light source (such as an LED or a laser diode (or "diode laser")). The term "light source" may also relate to a plurality of light sources, such as 2 to 200 (solid-state) LED light sources. Thus, the term LED may also refer to a plurality of LEDs. Furthermore, the term "light source" may also refer in embodiments to so-called chip-on-board (COB) light sources. The term "COB" refers in particular to an LED chip in the form of a semiconductor chip that is not encapsulated or connected, but is directly mounted on a substrate such as a PCB. Thus, several light-emitting semiconductor light sources may be arranged on the same substrate. In an embodiment, the COB is a multi-LED chip arranged together as a single lighting module.

[0019] The light source may have a light escape surface. For conventional light sources like light bulbs or fluorescent lamps, the light escape surface may be the outer surface of a glass or quartz envelope. In the case of an LED, the light escape surface may for example be the LED die or, if a resin is applied to the LED die, the outer surface of the resin. In principle, the light escape surface may also be the end of a fiber. The term escape surface particularly relates to the part of the light source where the light actually leaves or escapes from the light source. The light source is configured to provide a light beam. This light beam escapes from the light exit surface of the light source.

[0020] Similarly, the light-generating device may include a light escape surface, such as an end window.Further, similarly, the light-generating system may include a light escape surface, such as an end window.

[0021] The term "light source" may refer to a semiconductor light emitting device such as a light emitting diode (LED), a resonant cavity light emitting diode (RCLED), a vertical cavity laser diode (VCSEL), an edge emitting laser, etc. The term "light source" may also refer to an organic light emitting diode (OLED), such as a passive matrix (PMOLED) or active matrix (AMOLED). In certain embodiments, the light source comprises a solid state light source (such as an LED or a laser diode). In embodiments, the light source comprises an LED (light emitting diode). The term "light source" or "solid state light source" may also refer to a superluminescent diode (SLED).

[0022] The term LED can also refer to multiple LEDs.

[0023] The term "light source" may also refer to multiple (essentially identical (or different)) light sources, such as 2 to 2000 solid-state light sources. In embodiments, the light source may comprise one or more micro-optical elements (array of microlenses) downstream of a single solid-state light source, such as an LED, or downstream of multiple solid-state light sources (i.e. shared, for example, by multiple LEDs). In embodiments, the light source may comprise an LED with on-chip optics. In embodiments, the light source comprises a single pixelated LED (with or without optics) (in embodiments providing on-chip beam steering).

[0024] In an embodiment, the light source may be configured to provide a primary radiation to be used as such, for example a blue light source such as a blue LED, or a green light source such as a green LED, and a red light source such as a red LED. Such LEDs, which may not include a luminescent material ("phosphor"), may be denoted direct color LEDs.

[0025] However, in other embodiments, the light source may be configured to provide a primary radiation, a portion of which is converted into a secondary radiation. The secondary radiation may be based on conversion by a luminescent material. The secondary radiation may therefore also be referred to as luminescent material radiation. The luminescent material may in embodiments be included by the light source, such as an LED with a luminescent material layer or dome that includes the luminescent material. Such an LED may be referred to as a phosphor converted LED or PC LED. In other embodiments, the luminescent material may be configured at some distance from the light source ("remote"), such as an LED with a luminescent material layer that is not in physical contact with the LED die. Thus, in certain embodiments, the light source may be a light source that, in operation, emits light at least at a wavelength selected from the range of 380 to 470 nm. However, other wavelengths may also be possible. This light may be partially used by the luminescent material.

[0026] In embodiments, the light-generating device may comprise a luminescent material. In embodiments, the light-generating device may comprise a PC LED. In other embodiments, the light-generating device may comprise a direct LED (i.e. no phosphor). In embodiments, the light-generating device may comprise a laser device, such as a laser diode. In embodiments, the light-generating device may comprise a superluminescent diode. Thus, in certain embodiments, the light source may be selected from the group of laser diodes and superluminescent diodes. In other embodiments, the light source may comprise an LED.

[0027] The light source may be configured to generate a source light having, among other things, an optical axis (O), a (beam shape), and a spectral power distribution. The source light may, in embodiments, have one or more bands having a bandwidth as known for lasers.

[0028] The term "light source" may therefore refer to a light generating element itself, e.g. a solid-state light source, or may refer to a package of one or more of said light generating elements, e.g. a solid-state light source, and an element containing a luminescent material, and (other) optics, e.g. a lens, a collimator. A light conversion element ("conversion element" or "converter") may have an element containing a luminescent material. A solid-state light source itself, e.g. a blue LED, is a light source. A combination of a solid-state light source (e.g. a light generating element) and a light conversion element optically coupled to said solid-state light source, e.g. a blue LED and a light conversion element, may also be a light source (but may also be referred to as a light generating device). A white LED is therefore a light source (but may also be referred to as a (white) light generating device).

[0029] The term "light source" as used herein may refer to light sources including solid state light sources such as LEDs or laser diodes or superluminescent diodes.

[0030] The term "light source" may therefore also refer in embodiments to a light source that is (also) based on conversion of light, such as a light source in combination with a luminescence conversion material. The term "light source" may therefore also refer to a combination of an LED and a luminescent material configured to convert at least a portion of the radiation of the LED, or a combination of a (diode) laser and a luminescent material configured to convert at least a portion of the radiation of the (diode) laser.

[0031] In embodiments, the term "light source" may refer to a combination of a light source, such as an LED, and an optical filter that may change the spectral power distribution of the light generated by the light source. In particular, the term "light-generating device" may be used to refer to a light source and further optical components, such as optical filters and / or beam shaping elements.

[0032] The phrases "different light sources" or "multiple different light sources" and similar phrases may, in embodiments, refer to multiple solid-state light sources selected from at least two different bins. Similarly, the phrases "same light source" or "multiple identical light sources" and similar phrases may, in embodiments, refer to multiple solid-state light sources selected from the same bin.

[0033] The terms "solid-state light source" or "solid-state material light source" and similar terms may refer, among other things, to semiconductor light sources such as light emitting diodes (LEDs), diode lasers, or superluminescent diodes.

[0034] The term "laser source" refers in particular to a laser. Such a laser may be configured to generate laser source light having one or more wavelengths in the UV, visible or infrared, in particular having a wavelength selected from the spectral wavelength range of 200 to 2000 nm, such as 300 to 1500 nm. The term "laser" refers in particular to a device that emits light through a process of light amplification based on stimulated emission of electromagnetic radiation.

[0035] In particular, in embodiments, the term "laser" may refer to a solid-state laser. In certain embodiments, the term "laser" or "laser source," or similar terms, refer to a laser diode (or diode laser).

[0036] Thus, in an embodiment, the light source comprises a laser light source. In particular, in an embodiment herein, the light-generating device may comprise a laser light source.

[0037] In embodiments, the term "laser" or "solid-state laser" or "solid-state material laser" refers to any of the following lasers: cerium-doped lithium strontium (or calcium) aluminum fluoride (Ce:LiSAF, Ce:LiCAF), chromium-doped chrysoberyl (alexandrite) lasers, chromium-ZnSe (Cr:ZnSe) lasers, divalent samarium-doped calcium fluoride (Sm:CaF) lasers, Er:YAG lasers, erbium-doped and erbium-ytterbium cobalt lasers, erbium-doped chrom ... doped glass lasers, F-center lasers, Holmium (Ho:YAG) lasers, Nd:YAG lasers, NdCrYAG lasers, Neodymium doped yttrium calcium oxoborate Nd:YCa4O(BO3)3 or Nd:YCOB, Neodymium doped yttrium orthovanadate (Nd:YVO4) lasers, Neodymium glass (Nd:glass) lasers, Neodymium YLF (Nd:YLF) solid-state lasers, Promethium 147 doped phosphate glass (147Pm 3+ : Glass) solid-state laser, ruby ​​laser (Al2O3:Cr 3+ ), thulium YAG (Tm:YAG) laser, titanium sapphire (Ti:sapphire; Al2O3:Ti 3+ ) lasers, trivalent uranium-doped calcium fluoride (U:CaF2) solid-state lasers, ytterbium-doped glass lasers (rods, plates / chips and fibers), ytterbium YAG (Yb:YAG) lasers, Yb2O3 (glass or ceramics) lasers, etc.

[0038] For example, including embodiments for second and third harmonic generation, the light source may be an F center laser, an yttrium orthovanadate (Nd:YVO4) laser, a promethium-147 doped phosphate glass (147Pm 3+ :glass), and titanium sapphire (Ti:sapphire; Al2O3:Ti 3+ ) lasers. For example, taking into account second and third harmonic generation, such a light source can be used to generate blue light.

[0039] In embodiments, the terms "laser" or "solid state laser" or "solid state material laser" may refer to one or more of semiconductor laser diodes, such as GaN, InGaN, AlGaInP, AlGaAs, InGaAsP, lead-salt, vertical cavity surface emitting laser (VCSEL), quantum cascade laser, hybrid silicon laser, and the like.

[0040] A laser may be combined with an upconverter to reach shorter (laser) wavelengths. For example, upconversion can be achieved with some (trivalent) rare earth ions or with nonlinear crystals. In another example, a laser, such as a dye laser, can be combined with a downconverter to reach longer (laser) wavelengths.

[0041] As can be derived from the following, the term "laser source" may also refer to a plurality of (different or identical) laser sources. In certain embodiments, the term "laser source" may refer to a plurality of N (identical) laser sources. In embodiments, N=2 or more. In certain embodiments, N may be at least 5, such as in particular at least 8. In this way, higher brightness may be obtained. In embodiments, the laser sources may be arranged in a laser bank (see also above). The laser bank may in embodiments include a heat sink and / or optics, e.g. a lens for collimating the laser light. Thus, in embodiments, the lasers in a laser bank may share the same optics.

[0042] The laser source is configured to generate a laser source light (or "laser light"). The source light may consist essentially of the laser source light. The source light may also comprise the laser source light of two or more (different or the same) laser sources. For example, the laser source light of the two or more (different or the same) laser sources may be coupled into a light guide to provide a single light beam comprising the laser source light of the two or more (different or the same) laser sources. Thus, in certain embodiments, the source light is in particular a collimated source light. In yet other embodiments, the source light is in particular a (collimated) laser source light.

[0043] The laser source light may, in embodiments, have one or more bands, with a bandwidth as known for lasers. In certain embodiments, the bands may be relatively sharp lines, such as having a full width half maximum (FWHM) in the range of less than 20 nm at room temperature (RT), such as 10 nm or less. Thus, the source light has a spectral power distribution (intensity in energy scale as a function of wavelength) that may include one or more (narrow) bands.

[0044] The (source light) beam may be a focused or collimated beam of (laser) source light. The term "focused" may in particular refer to converging to a small spot. This small spot may be at a discrete converter region or may be (slightly) upstream or (slightly) downstream of the discrete converter region. In particular, the 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) is essentially not larger than the cross-sectional shape (perpendicular to the optical axis) of the discrete converter region (where the source light illuminates the discrete converter region). Focusing may be performed with one or more optical systems, such as (focusing) lenses. In particular, two lenses may be applied to focus the laser source light. Collimation may be performed with one or more (other) optical systems, such as collimation elements, such as lenses and / or parabolic mirrors. In embodiments, the beam of (laser) source light may be relatively highly collimated, such as ≦2° (FWHM), more particularly ≦1° (FWHM), most particularly ≦0.5° (FWHM). Thus, ≦2° (FWHM) may be considered as (highly) collimated source light. Optical systems may be used to provide the (highly) collimated light (see also above).

[0045] The term "solid state laser" and similar terms may refer to solid state lasers such as those based on crystals or glasses doped with ions such as transition metal ions and / or lanthanide ions, fiber lasers, photonic crystal lasers, semiconductor lasers such as vertical cavity surface emitting lasers (VCSELs), and the like.

[0046] The term "solid-state light source" and similar terms may refer to semiconductor light sources, such as light emitting diodes (LEDs), diode lasers, or superluminescent diodes, among others.

[0047] The term "laser light source" may refer to, for example, a diode laser or a solid-state laser.

[0048] As mentioned above, the light generating system may comprise a first light generating device, a second light generating device and a luminescent material. More particularly, in consideration of the tunability of the color gamut, CRI and / or CCT, the system may further comprise a third light generating device. Furthermore, for controllability, the system may further comprise a control system. Thus, in particular, the light generating system comprises a first light generating device, a second light generating device, a third light generating device, a luminescent material and a control system. An embodiment thereof will be further described below.

[0049] In particular, the first light-generating device may comprise a laser light source. The term "laser light source" may also refer to a plurality of (essentially) identical laser light sources. In particular, the first light-generating device is configured to generate a first device light. The first device light may have a first device peak wavelength (λ1). The first peak wavelength of the first device light may be within about + / - 5 nm of a centroid wavelength of the first device light. Furthermore, the first device light has a first spectral power distribution.

[0050] In particular, the second light-generating device may comprise a laser light source. The term "laser light source" may also refer to a plurality of (essentially) identical laser light sources. In particular, the second light-generating device is configured to generate a second device light. The second device light may have a second device peak wavelength (λ2). The second peak wavelength of the second device light may be within about + / - 5 nm of a centroid wavelength of the second device light. Furthermore, the second device light has a second spectral power distribution, different from the first spectral power distribution.

[0051] In particular, the third light-generating device may comprise a laser light source. The term "laser light source" may also refer to a plurality of (essentially) identical laser light sources. In particular, the third light-generating device is configured to generate a third device light. The third device light may have a third device peak wavelength (λ3). The third peak wavelength of the third device light may be within about + / - 5 nm of a centroid wavelength of the third device light. Furthermore, the third device light has a third spectral power distribution different from the first spectral power distribution and different from the second spectral power distribution.

[0052] Therefore, the first spectral power distribution, the second spectral power distribution, and the third spectral power distribution may be different from each other.

[0053] The term "centroid wavelength", also denoted λc, is known in the art and refers to the wavelength value where half of the light energy is at the shorter wavelength and half of the light energy is at the longer wavelength, the value being given in nanometers (nm). It is the wavelength that divides into two equal parts the integral of the spectral power distribution as expressed by the formula λc=Σλ×I(λ) / (ΣI(λ)), the summation being over the wavelength range of interest, where I(λ) is the spectral energy density (i.e., the integral of the product of wavelength and intensity over the emission band normalized to the integrated intensity). The centroid wavelength may be determined, for example, in operating conditions.

[0054] In particular, λ1 and λ2 may be selected from the wavelength range of 420 to 495 nm, such as in an embodiment from the wavelength range of 420 to 490 nm. In a particular embodiment, both the first device light and the second device light are blue light.

[0055] In a particular embodiment, the first device peak wavelength (λ1) is selected from the wavelength range of 445 to 475 nm. More particularly, the first device peak wavelength (λ1) may be selected from the wavelength range of 450 to 470 nm. Thus, the first device light may be blue light.

[0056] The term "purple light" or "purple emission" particularly relates to light having a wavelength in the range of about 380 to 440 nm. The term "blue light" or "blue emission" particularly relates to light having a wavelength in the range of about 440 to 495 nm (including some purple and cyan hues). The term "green light" or "green emission" particularly relates to light having a wavelength in the range of about 495 to 570 nm. The term "yellow light" or "yellow emission" particularly relates to light having a wavelength in the range of about 570 to 590 nm. The term "orange light" or "orange emission" particularly relates to light having a wavelength in the range of about 590 to 620 nm. The term "red light" or "red emission" particularly relates to light having a wavelength in the range of about 620 to 780 nm. The term "pink light" or "pink emission" refers to light having a blue component and a red component. The term "cyan" may refer to one or more wavelengths selected from the range of about 490 to 520 nm. The term "amber" may refer to one or more wavelengths selected from a range of about 585-605 nm, such as about 590-600 nm. The phrase "light having one or more wavelengths within a wavelength range" and similar phrases may specifically indicate that the light (or radiation) being indicated has a spectral power distribution with at least one or more intensities at those one or more wavelengths within the wavelength range being indicated. For example, a blue-emitting solid-state light source has a spectral power distribution with intensities at one or more wavelengths within a wavelength range of 440-495 nm.

[0057] In an embodiment, the second device peak wavelength (λ2) may be selected from the range of 420 to 450 nm or the range of 470 to 490 nm. Thus, the second device light may be blue light or bluish light in an embodiment.

[0058] In an embodiment, |λ1-λ2|≧10 nm, more particularly, |λ1-λ2|≧15 nm. Even more particularly, |λ1-λ2|≧20 nm. Thus, the first device light and the second device light may have different color points.

[0059] In particular embodiments, the colors or color points of the first and second types of light may differ if the respective color points of said first and second types of light differ by at least 0.01 with respect to u' and / or at least 0.01 with respect to v', even more particularly at least 0.02 with respect to u' and / or at least 0.02 with respect to v'. In even more particular embodiments, the respective color points of said first and second types of light may differ by at least 0.03 with respect to u' and / or at least 0.03 with respect to v', where u' and v' are the color coordinates of the light in the CIE 1976 UCS (Uniform Chromaticity) diagram.

[0060] Further, in an embodiment, |λ1-λ2|≦60 nm. Good results have been obtained when |λ1-λ2|≦50 nm, such as |λ1-λ2|≦45 nm, and in an embodiment, |λ1-λ2|≧15 nm is applied.

[0061] In an embodiment, the first device peak wavelength (λ1) may be selected from a wavelength range of 453 to 467 nm. In an embodiment, the second device peak wavelength (λ2) may be selected from a wavelength range of 425 to 440 nm. In another example, in an embodiment, the second device peak wavelength (λ2) may be selected from a wavelength range of 470 to 480 nm.

[0062] In an embodiment, the third device peak wavelength (λ3) may be selected from a wavelength range of 590 to 780 nm, more particularly from a wavelength range of 600 to 650 nm. In a particular embodiment, the third device peak wavelength (λ3) may be selected from a wavelength range of 610 to 640 nm. In particular, this may be a beneficial choice in terms of color gamut, CRI, CCT tunability, and efficiency. In an embodiment, the third device peak wavelength (λ3) may be selected from a wavelength range of at least 620 nm, such as from a range of 620 to 640 nm. In an embodiment, the third device peak wavelength (λ3) may be selected from a wavelength range of up to 640 nm, such as from a range of 610 to 640 nm.

[0063] Therefore, the first peak wavelength, the second peak wavelength, and the third peak wavelength may be peak wavelengths of laser light from a laser light source.

[0064] Additionally, the system may comprise a luminescent material.

[0065] Several embodiments of luminescent materials are described below.

[0066] The term "luminescent material" refers in particular to a material capable of converting a first radiation, in particular one or more of UV and blue radiation, into a second radiation. Generally, the first and second radiation have different spectral power distributions. Therefore, instead of the term "luminescent material", the term "luminescence converter" or "converter" may also be applied. Generally, the second radiation has a spectral power distribution at a larger wavelength than the first radiation, which is the case of so-called down-conversion. However, in certain embodiments, the second radiation has a spectral power distribution with an intensity at a smaller wavelength than the first radiation, which is the case of so-called up-conversion.

[0067] In embodiments, the "luminescent material" may refer specifically to a material capable of converting radiation, for example to visible light and / or infrared light. For example, in embodiments, the luminescent material may be capable of converting one or more of UV radiation and blue radiation into visible light. The luminescent material may also convert radiation into infrared radiation (IR) in certain embodiments. Thus, when excited with radiation, the luminescent material emits radiation. In general, the luminescent material is a downconverter, i.e., a material capable of converting radiation of a smaller wavelength into radiation of a larger wavelength (λ ex <λ em ), in certain embodiments, the luminescent material may comprise an upconverter luminescent material, i.e., the larger wavelength radiation is converted to radiation having a smaller wavelength (λ ex >λ em ) is converted into radiation with a

[0068] In embodiments, the term "luminescence" may refer to phosphorescence. In embodiments, the term "luminescence" may refer to fluorescence. Instead of the term "luminescence", the term "emission" may be applied. Thus, the terms "first radiation" and "second radiation" may refer to excitation radiation and luminescence (radiation), respectively. Similarly, the term "luminescent material" may refer to phosphorescence and / or fluorescence, in embodiments.

[0069] The term "luminescent material" may refer to a number of different luminescent materials. Examples of possible luminescent materials are provided below. Thus, the term "luminescent material" may, in certain embodiments, refer to a luminescent material composition.

[0070] In an embodiment, the luminescent material is selected from garnets and nitrides, in particular doped with trivalent cerium or divalent europium, respectively. The term "nitride" may also refer to oxynitrides or nitridosilicates, etc. Alternatively or in addition, the luminescent material may be selected from silicates, in particular doped with divalent europium.

[0071] In certain embodiments, the luminescent material is ABO. 12 :Ce type luminescent materials, where A in embodiments comprises one or more of Y, La, Gd, Tb and Lu, in particular (at least) one or more of Y, Gd, Tb and Lu, and B in embodiments comprises one or more of Al, Ga, In and Sc. In particular, A may comprise one or more of Y, Gd and Lu, in particular one or more of Y and Lu. In particular, B may comprise at least Al, such as one or more of Al and Ga, more in particular essentially only Al. Thus, a particularly suitable luminescent material is a cerium comprising garnet material. Garnet embodiments are in particular of the type A3B5O 12The present invention includes a garnet, A including at least yttrium or lutetium, and B including at least aluminum. Such garnets may be doped with cerium (Ce), praseodymium (Pr), or a combination of cerium and praseodymium, but in particular with Ce. In particular, B may include aluminum (Al), but B may also include, in addition to aluminum, gallium (Ga) and / or scandium (Sc) and / or indium (In), in part, in particular up to about 20% of B, more in particular up to about 10% of B (i.e., B ions consist essentially of 90 mol % or more of Al and 10 mol % or less of one or more of Ga, Sc and In). B may in particular include up to about 10% of gallium. In another variant, B and O may be at least in part replaced by Si and N. The element A may be selected from the group consisting of yttrium (Y), gadolinium (Gd), terbium (Tb), and lutetium (Lu). Furthermore, Gd and / or Tb are particularly present in an amount up to about 20% of A. In a particular embodiment, the garnet luminescent material is selected from the group consisting of (Y 1-x Lu x )3B5O 12 :Ce, where x is 0 or more and 1 or less. The term ":Ce" indicates that some of the metal ions in the luminescent material (i.e., in garnets, some of the "A" ions) are replaced with Ce. For example, (Y 1-x Lu x )3AlO 12 In the case of Ce, part of Y and / or Lu is replaced by Ce. This is known to those skilled in the art. Ce replaces A, generally up to 10%, and generally the Ce concentration is in the range of 0.1 to 4%, in particular 0.1 to 2% (relative to A). Assuming 1% Ce and 10% Y, the perfectly correct formula is (Y 0.1 Lu 0.89 Ce 0.01 )3AlO 12 The Ce in the garnet may be substantially or exclusively in the trivalent state, as known to those skilled in the art.

[0072] In an embodiment, the luminescence material comprises (thus) A3B5O 12 and in a particular embodiment, up to 10% of the B-O can be replaced by Si-N.

[0073] In a particular embodiment, the luminescence material is (Y x1-x2-x3 A' x2 Ce x3 )3(Al y1-y2 B' y2 )5O 12 where x1 + x2 + x3 = 1, x3 > 0, 0 < x2 + x3 ≤ 0.2, y1 + y2 = 1, 0 ≤ y2 ≤ 0.2, A' comprises one or more elements selected from the group consisting of lanthanides, and B' comprises one or more elements selected from the group consisting of Ga, In, and Sc. In an embodiment, x3 is selected from the range of 0.001 to 0.1. In the present invention, in particular, x1 > 0, such as at least 0.8, such as x1 > 0.2. Garnet comprising Y can provide an appropriate spectral power distribution.

[0074] In a particular embodiment, up to 10% of the B-O can be replaced by Si-N. Here, B in B-O refers to one or more of Al, Ga, In, and Sc (and O refers to oxygen), and in a particular embodiment, B-O may refer to Al-O. As described above, in a particular embodiment, x3 can be selected from the range of 0.001 to 0.04. In particular, such a luminescence material has an appropriate spectral distribution (see below), has a relatively high efficiency, has a relatively high thermal stability, and can enable a high CRI (optionally in combination with the light of other light sources as described herein). Thus, in a particular embodiment, A can be selected from the group consisting of Lu and Gd. Alternatively, or in addition, B can include Ga. Thus, in an embodiment, the luminescence material is (Y x1-x2-x3 (Lu,Gd) x2 Ce x3 )3(Al y1-y2 Gay2 )5O 12 which includes, and Lu and / or Gd may be available. Even more particularly, x3 is selected from the range of 0.001 to 0.1, 0 < x2 + x3 ≤ 0.1, and 0 ≤ y2 ≤ 0.1. Further, in certain embodiments, up to 1% of B-O can be replaced by Si-N. Here, the percentage refers to moles (as is known in the art), for example, see also EP3149108. In yet other specific embodiments, the luminescence material is (Y x1-x3 Ce x3 )3Al5O 12 which includes, x1 + x3 = 1, 0 < x3 ≤ 0.2, and is, for example, from 0.001 to 0.1, etc.

[0075] In certain embodiments, the light generating device may only include a luminescence material selected from the type of garnet containing cerium. In still other specific embodiments, the light generating device includes a single type of luminescence material such as (Y x1-x2-x3 A' x2 Ce x3 )3(Al y1-y2 B' y2 )5O 12 Thus, in certain embodiments, the light generating device has a luminescence material, and at least 85% by weight, even more particularly at least about 90% by weight, for example even more particularly at least about 95% by weight of the luminescence material is (Y x1-x2-x3 A' x2 Ce x3 )3(Al y1-y2 B' y2 )5O 12It includes. Here, A' contains one or more elements selected from the group consisting of lanthanides, B' contains one or more elements selected from the group consisting of Ga, In, and Sc, x1 + x2 + x3 = 1, x3 > 0, 0 < x2 + x3 ≤ 0.2, y1 + y2 = 1, and 0 ≤ y2 ≤ 0.2. In particular, x3 is selected from the range of 0.001 to 0.1. It should be noted that in an embodiment, x2 = 0. Instead of or in addition to this, in an embodiment, y2 = 0.

[0076] In certain embodiments, A may particularly include at least Y, and B may particularly include at least Al.

[0077] Instead of or in addition to this, the luminescence material 11 :Ce 3+ type of luminescence material may be included, and A includes one or more of Y, La, Gd, Tb, and Lu, such as one or more of La and Y in an embodiment.

[0078] In an embodiment, the luminescence material may, instead of or in addition to this, be MS:Eu 2+ and / or M2Si5N8:Eu 2+ and / or MAlSiN3:Eu 2+ and / or Ca2AlSi3O2N5:Eu 2+and the like, where M comprises one or more of Ba, Sr and Ca, and in particular embodiments at least Sr. Thus, in embodiments, the luminescent material may comprise one or more materials selected from the group consisting of (Ba,Sr,Ca)S:Eu, (Ba,Sr,Ca)AlSiN3:Eu and (Ba,Sr,Ca)2Si5N8:Eu. In these compounds, europium (Eu) is substantially or exclusively divalent and replaces one or more of the divalent cations indicated. Generally, Eu is not present in an amount greater than 10% of the cations, and the presence of Eu is particularly in the range of about 0.5 to 10%, more particularly in the range of about 0.5 to 5%, relative to the cation it replaces. The term ":Eu" refers to the presence of a portion of the metal ions that are not Eu (in these examples Eu 2+ For example, assuming 2% Eu in CaAlSiN3:Eu, the correct formula is (Ca 0.98 EU 0.02 )AlSiN3. Divalent europium generally replaces divalent cations, such as the divalent alkaline earth cations mentioned above, in particular Ca, Sr or Ba. The material (Ba,Sr,Ca)S:Eu may also be denoted MS:Eu, where M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca), in particular M includes calcium or strontium, or calcium and strontium, more particularly calcium, in this compound, where Eu is introduced to replace at least a portion of M (i.e. one or more of Ba, Sr and Ca). Furthermore, the material (Ba,Sr,Ca)2Si5N8:Eu may also be denoted M2Si5N8:Eu, where M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca), in particular M includes Sr and / or Ba in this compound. In a further particular embodiment, M consists of Sr and / or Ba (not taking into account the presence of Eu), Ba 1.5 Sr 0.5In particular, it consists of 50-100%, more particularly 50-90% Ba and 50-0%, particularly 50-10% Sr, such as Si5N8:Eu (i.e. 75% Ba; 25% Sr), where Eu is introduced to replace at least a portion of M (i.e. one or more of Ba, Sr and Ca). Similarly, the material (Ba,Sr,Ca)AlSiN3:Eu may also be denoted as MAlSiN3:Eu, where M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca), in particular M includes calcium or strontium, or calcium and strontium, more particularly calcium, in this compound. In particular, Eu is introduced to replace at least a portion of M (i.e. one or more of Ba, Sr and Ca). The Eu in the above luminescent materials is substantially or exclusively in a divalent state, as known to those skilled in the art.

[0079] In embodiments, the red luminescent material may include one or more materials selected from the group consisting of (Ba,Sr,Ca)S:Eu, (Ba,Sr,Ca)AlSiN3:Eu, and (Ba,Sr,Ca)2Si5N8:Eu. In these compounds, europium (Eu) is substantially or exclusively divalent and replaces one or more of the divalent cations shown. Generally, Eu is not present in an amount greater than 10% of the cations, and the presence of Eu is particularly in the range of about 0.5 to 10%, more particularly in the range of about 0.5 to 5%, relative to the cation it replaces. The term ":Eu" indicates that a portion of the metal ions is Eu (in these examples Eu 2+ For example, assuming 2% Eu in CaAlSiN3:Eu, the correct formula is (Ca 0.98 EU 0.02 )AlSiN3. Divalent europium generally replaces a divalent cation, such as the divalent alkaline earth cations mentioned above, particularly Ca, Sr or Ba.

[0080] The material (Ba,Sr,Ca)S:Eu is sometimes denoted as MS:Eu, where M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca), and in particular M comprises calcium or strontium, or calcium and strontium, more particularly calcium, in this compound, where Eu is introduced to replace at least a portion of M (i.e. one or more of Ba, Sr and Ca).

[0081] Furthermore, the material (Ba,Sr,Ca)2Si5N8:Eu may also be denoted as M2Si5N8:Eu, where M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca), and in particular, M in this compound comprises Sr and / or Ba. In further particular embodiments, M consists of Sr and / or Ba (not taking into account the presence of Eu), and Ba 1.5 Sr 0.5 Particularly consisting of 50-100%, more particularly 50-90% Ba, and 50-0%, particularly 50-10% Sr, such as Si5N8:Eu (i.e., 75% Ba; 25% Sr), where Eu is introduced to replace at least a portion of M (i.e., one or more of Ba, Sr and Ca).

[0082] Similarly, the material (Ba,Sr,Ca)AlSiN3:Eu may also be denoted as MAlSiN3:Eu, where M is one or more elements selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca), and in particular M comprises calcium or strontium, or calcium and strontium, more particularly calcium, in this compound, where Eu is introduced to replace at least a portion of M (i.e. one or more of Ba, Sr and Ca).

[0083] The Eu in the above luminescent materials is substantially or exclusively in a divalent state, as known to those skilled in the art.

[0084] The blue luminescent material is YSO (Y2SiO5:Ce 3+ ), or a similar compound, or BAM (BaMgAl 10 O 17 :EU 2+ ), or a similar compound.

[0085] The term "luminescent material" as used herein relates specifically to inorganic luminescent materials.

[0086] Instead of the term "luminescent material", the term "phosphor" is sometimes applied, these terms being known to those skilled in the art.

[0087] Alternatively or additionally, other luminescent materials may be applied, for example quantum dots and / or organic dyes, optionally embedded in a transparent matrix, for example a polymer such as PMMA or polysiloxane.

[0088] Quantum dots are small crystals of semiconductor materials, generally with a width or diameter of only a few nanometers. When excited by incident light, quantum dots emit light with a color determined by the size and material of the crystal. Thus, by adapting the size of the dots, light of a specific color can be generated. Most known quantum dots that emit in the visible range are based on cadmium selenide (CdSe) with shells such as cadmium sulfide (CdS) and zinc sulfide (ZnS). Cadmium-free quantum dots such as indium phosphide (InP) and copper indium sulfide (CuInS2) and / or silver indium sulfide (AgInS2) can also be used. Quantum dots exhibit very narrow emission bands, therefore they exhibit saturated colors. Moreover, the emission color can be easily tuned by adapting the size of the quantum dots. In the present invention, any type of quantum dot known in the art can be used. However, for reasons of environmental safety and concerns, it may be preferable to use cadmium-free quantum dots, or at least quantum dots that have a very low cadmium content.

[0089] Instead of or in addition to quantum dots, other quantum confinement structures may be used, where "quantum confinement structure" is to be understood in the context of this application as, for example, quantum wells, quantum dots, quantum rods, tripods, tetrapods, or nanowires.

[0090] Organic phosphors can also be used. Examples of suitable organic phosphor materials are organic luminescent materials based on perylene derivatives, such as the compounds sold by BASF under the name Lumogen®. Examples of suitable compounds include, but are not limited to, Lumogen® Red F305, Lumogen® Orange F240, Lumogen® Yellow F083, and Lumogen® F170.

[0091] Different luminescent materials may have different spectral power distributions of their respective luminescent material light. Alternatively, or in addition, such different luminescent materials may have, among other things, different color points (or dominant wavelengths).

[0092] As mentioned above, other luminescent materials may be possible. Thus, in certain embodiments, the luminescent material is selected from the group of divalent europium-containing nitrides, divalent europium-containing oxynitrides, divalent europium-containing silicates, cerium-containing garnets, and quantum structures. The quantum structures may include, for example, quantum dots or quantum rods (or other quantum-type particles) (see above). The quantum structures may also include quantum wells. The quantum structures may also include photonic crystals.

[0093] In particular, the luminescent material may be a broadband emitter.

[0094] The luminescent material may be selected to obtain an emission band with a full width at half maximum (of the luminescent material light) of at least 40 nm, such as at least 50 nm. For example, the luminescent material may be selected to obtain an emission band with a full width at half maximum of at least 60 nm. This may be the case, for example, for a garnet luminescent material containing trivalent cerium (as described herein). Thus, in particular, the luminescent material may include a broadband emitter. The luminescent material may also have a plurality of broadband emitters. In particular, when two or more luminescent materials are applied to convert at least a portion of the first device light and / or at least a portion of the second device light, at least two of the two or more luminescent materials may be configured to provide a respective luminescent material light having an emission band with a full width at half maximum (of the luminescent material light) of at least 40 nm, such as at least 50 nm.

[0095] Thus, in certain embodiments, the luminescent material is ABO 12:Ce type luminescent material, A includes one or more of Y, La, Gd, Tb and Lu, and B includes one or more of Al, Ga, In and Sc. In particular, A may include Lu. More particularly, in an embodiment, A includes at least 40 at.%, more particularly at least 50 at.% Lu. Alternatively or in addition, B may include at least 90 at.% Al. In an embodiment, cerium is available in an amount of 0.01 to 3 at.%, such as up to about 1 at.%, relative to A, selected from the range of 0.1 to 2 at.% (i.e. 0.01 to 3% of all A atoms may be Ce).

[0096] In an embodiment, the luminescent material is (Y,Lu)3(Al,Ga)5O 12 % of Y+Lu+Ce, in particular cerium may be available in an amount of 0.01-3 at.%, such as up to about 1 at.%, selected from the range of 0.1-2 at.%, relative to Y+Lu+Ce, Lu is available in an amount of at least 50 at.%, relative to Y+Lu+Ce, and Al is available in an amount of at least 90 at.% relative to Al+Ga. In an embodiment, the luminescent material comprises 0.2-1 at.% of cerium relative to A.

[0097] In particular, the luminescent material is excitable by the first device light and the second device light. The phrase "excitable by the first device light and the second device light" and similar phrases may indicate in particular that the luminescent material can be excited by the first device light and can be excited by the second device light. However, this does not necessarily mean that in operation the luminescent material is excited by both the first device light and the second device light, since in an embodiment in an operational mode only one of the first device light and the second device light may be provided.

[0098] Thus, the first light-generating device may be referred to as a “pump” or a “pump light source,” and the first device light may be referred to as “pump light.” Similarly, the second light-generating device may be referred to as a “pump” or a “pump light source,” and the second device light may be referred to as “pump light.”

[0099] Thus, in particular, the luminescent material is configured to convert at least a portion of one or more of the first device light and the second device light into luminescent material light, the luminescent material light having a centroid wavelength λ 2 within a green to orange wavelength range. c,1 The green to orange wavelength range may in particular refer to a wavelength range of 495 to 620 nm. In particular, the luminescent material light has a centroid wavelength λ 2 in the green to yellow wavelength range, i.e. in the wavelength range of 495 to 590 nm. c,1 may have the following structure:

[0100] The luminescent material light may have a luminescent material light spectral power distribution.

[0101] Thus, the first spectral power distribution, the second spectral power distribution, the third spectral power distribution and the luminescent material light spectral power distribution may be different from each other.

[0102] In particular, the luminescent material has an absorbance band having a first absorbance E1 at the first device peak wavelength (λ1) and a second absorbance E2 at the second device peak wavelength (λ2).

[0103] The absorbance can be determined by methods known in the art. A transparent phosphor plate can be used in a UV-Vis spectrometer, which measures the intensity with and without a sample and calculates the absorbance from the intensity. At the first peak wavelength, relatively less blue light may remain due to more absorption compared to the second peak wavelength, and at the second peak wavelength, more blue light may remain unconverted due to less absorption (compared to the first peak wavelength). Thus, in particular, E2 / E1<1. E1 and E2 can be determined from the absorbance spectrum of the luminescent material light.

[0104] In particular, the centroid wavelength λ of the luminescent material c,1 is not too close to the third device optical peak wavelength. c,1 -λ3|≧20 nm, and more particularly, in certain embodiments, |λ c,1 -λ3|≧30 nm, such that |λ c,1 -λ3|≧25 nm. In yet another embodiment, |λ c,1 -λ3|≦125 nm, etc. c,1 -λ3|≦150 nm, more particularly |λ c,1 −λ3|≦100 nm.

[0105] As mentioned above, the system may further comprise a control system. In particular, the control system may be configured to control at least the first light-generating device and the second light-generating device. Furthermore, in an embodiment, the control system may be configured to control the first light-generating device, the second light-generating device and the third light-generating device.

[0106] The term "control" and similar terms refer in particular to at least determining the behavior of an element or supervising the operation of an element. Thus, in this specification, the term "control" and similar terms may refer to, for example, imposing a behavior on the element (determining the behavior of an element or supervising the operation of an element), such as, for example, measuring, indicating, activating, opening, shifting, changing temperature, etc. The term "control" and similar terms may further include monitoring as well. Thus, the term "control" and similar terms may include imposing a behavior on an element and may include imposing a behavior on an element and monitoring the element. The control of the element may be performed by a control system, which may be denoted as a "controller". Thus, the control system and the element may be functionally coupled, at least temporarily or permanently. The element may comprise the control system. In an embodiment, the control system and the element may not be physically coupled. The control may be performed via wired and / or wireless control. The term "control system" may also refer to a number of different control systems, particularly those that are functionally coupled, for example one control system of the number of different control systems may be a master control system and one or more other control systems may be slave control systems. A control system may have a user interface or may be functionally coupled to a user interface.

[0107] The control system may also be configured to receive and execute instructions from a remote control device. In an embodiment, the control system may be controlled via an app on a device, such as a smartphone or portable device, such as an iPhone, tablet, etc. Thus, the device is not necessarily coupled to the lighting system, but may be (temporarily) functionally coupled to the lighting system.

[0108] Thus, in an embodiment, the control system may (also) be configured to be controlled by an app on a remote device. In such an embodiment, the control system of the lighting system may be a slave control system or may control in slave mode. For example, the lighting systems may be identifiable by a code, in particular a unique code for each lighting system. The control system of the lighting system may be configured to be controlled by an external control system that accesses the lighting system based on knowledge entered by a user interface comprising an optical sensor (e.g. a QR code reader) of the (unique) code. The lighting system may also have means for communicating with other systems or devices, such as based on Bluetooth, WIFI, LiFi, ZigBee, BLE or WiMAX, or another wireless technology.

[0109] The system, or apparatus, or device may perform an operation in a "mode" or "operational mode" or "mode of operation" or "operable mode". The term "operational mode" may also be indicated as "control mode". Similarly, in a method, an operation, or a stage, or a step may be performed in a "mode" or "operational mode" or "mode of operation" or "operable mode". This does not exclude that the system, or apparatus, or device may also be adapted to provide another control mode or multiple other control modes. Similarly, this may not exclude that one or more other modes may be performed before and / or after performing the mode.

[0110] However, in embodiments, a control system may be available that is adapted to provide at least said control mode. If other modes are available, the selection of such modes may in particular be performed via a user interface, although other options may also be possible, such as performing the mode depending on a sensor signal or a (time) scheme. The operating mode may also refer in embodiments to a system, or apparatus, or device that can only operate in a single operating mode (i.e. "on", without further adjustability).

[0111] Thus, in an embodiment, the control system may be dependent on one or more of a user interface input signal, a sensor signal (of a sensor), and a timer, where the term "timer" may refer to a clock and / or a predefined timing scheme.

[0112] For example, in an embodiment, the control system may be configured to control the first device light and the second device light within a ratio of 1:100 to 100:1, the ratio being defined by the radiant flux of the first device light (I1) compared to the radiant flux of the second device light (I2), i.e. 0.01≦I1 / I2≦100. In an embodiment, the control system may be configured to control the first device light and the second device light within a ratio of 0.1≦I1 / I2≦10. Within such a range, the CCT may be adjusted between a maximum value and a minimum value. However, other ranges are not excluded herein. It is noted that the CCT may also be controlled by controlling the third light generating device. Thus, the control system may also be configured to control the third device light.

[0113] The term "radiant flux" may in particular refer to the radiant energy emitted per unit time (by the light-generating device). Instead of the term "radiant flux", the terms "intensity" or "radiant power" may also be applied. The term "radiant flux" may have units of energy, in particular watts. The term "spectral power distribution" may in particular refer to the power distribution of light (in particular in watts) as a function of wavelength (in particular in nanometers), in particular in embodiments spanning the human visible wavelength range (380-780 nm). In particular, the term "spectral power distribution" may refer to the radiant flux per unit frequency or wavelength, often expressed in watts / nm. Instead of the term "spectral power distribution", the term "spectral flux" may also be applied. Thus, instead of the phrase "controllable spectral power distribution", the phrase "controllable spectral flux" may also be applied. The spectral flux may be expressed as power (watts) per unit frequency or wavelength. In particular, in the present specification, the spectral flux is expressed as radiant flux per unit wavelength (W / nm). Furthermore, in this specification, the spectral flux and radiant flux are based on the spectral power of the device light over the wavelength range of 380 to 780 nm, among others.

[0114] In an embodiment, the system may be configured to provide a white system light. Thus, in an operational mode, the system light may be white light. In an embodiment, the system may be capable of implementing multiple operational modes, such as a system light with a controllable spectral power distribution. In another embodiment, the operational mode may be a controllable mode, in which the spectral power distribution can be controlled, depending on a sensor, etc.

[0115] Thus, in an embodiment, the light production system may be configured to provide white system light in an operational mode.

[0116] In particular embodiments, the (white) system light may comprise the first device light, the second device light and the luminescent material light. More particularly, the (white) system light may comprise the first device light, the second device light, the luminescent material light and the third device light. In embodiments, the white system light may comprise the first device light, the second device light, the luminescent material light and the third device light, and the radiant flux of the first device light to the radiant flux of the second device light may be selected from the range of 1:100 to 100:1, and the radiant flux of the third device light to the total radiant flux of the first device light and the second device light may be selected from the range of 1:100 to 100:1.

[0117] The term "white light" in this specification is known to those skilled in the art. The white light particularly relates to light having a correlated color temperature (CCT) between about 2000K and 20000K, particularly between 2700K and 20000K, particularly between about 1800K and 20000K, such as between about 2700K and 6500K for general illumination. In an embodiment, for backlight applications, the correlated color temperature (CCT) may particularly be within about 7000K and 20000K. In yet another embodiment, the correlated color temperature (CCT) is particularly within about 15 SDCM (standard deviation of color matching) from the BBL (black body locus), particularly within about 10 SDCM from the BBL, and even more particularly within about 5 SDCM from the BBL.

[0118] In an embodiment, the control system is configured to control the spectral power distribution of the system light, and the control system is configured to control the correlated color temperature of the system light to a value selected from a range of 1800 to 6500 K, the correlated color temperature of the system light being controllable within the range of 1800 to 6500 K over a CCT control range of at least 500 K, such as a CCT control range of at least 1000 K. For example, the CCT of the system light may be controllable between 2700 to 4000 K (i.e. over a CCT control range of 1300 K), or over a range of 2000 to 4500 K (i.e. over a CCT control range of 2500 K).

[0119] In embodiments, R9 may be at least 0, particularly at least 20 or even more particularly at least 30. In other examples, the R9 value may be controllable over a range of at least 20, such as between 20 and 40. In particular embodiments, the control system may be configured to control the R9 value of the system light (in the first mode of operation) to a value of at least 30, and the R9 value of the system light may be controllable over an R9 control range of at least 30, the R9 control range at least partially overlapping with a range of at least 30. Furthermore, in particular embodiments, the color rendering index of the system light (in the first mode of operation) may be at least 80.

[0120] In an embodiment, the control system may be configured to control the R9 value of the system light to a value of at least 30 and the color rendering index of the system light may be at least 75, such as at least 80, and in an embodiment at least 85.

[0121] It should be noted that the CRI may also depend on the spectral power composition, so different types of white light may have different CRI and / or R9 values.

[0122] In certain embodiments, the correlated color temperature of the system light may be controllable over a CCT control range of at least 1000K within a range of 2000-6000K.

[0123] As mentioned above, the second device peak wavelength (λ2) may be selected from the range of 420 to 450 nm. In another example, the second device peak wavelength (λ2) may be selected from the range of 470 to 490 nm. From the viewpoint of energy efficiency, the latter may be more desirable than the former. From the viewpoint of CCT tunability, the former may be more desirable than the latter.

[0124] In certain embodiments, there may be two second device peak wavelengths provided by two different second light-generating devices, where one type of second light-generating device configured to generate second device light with the second device peak wavelength (λ2) may be selected from the range of 420 to 450 nm, and another type of second light-generating device configured to generate second device light with the second device peak wavelength (λ2) may be selected from the range of 470 to 490 nm.

[0125] In an embodiment, the first light-generating device and the second light-generating device are arranged in a single laser bank. Alternatively or in addition, the system may have a plurality of first light-generating devices arranged in a single laser bank. Alternatively or in addition, the system may have a plurality of second light-generating devices arranged in a single laser bank. The latter two single laser banks may be different or the same. In an embodiment, the lasers in a laser bank may share the same optics.

[0126] In an embodiment, E2 / E1≦0.5, more particularly E2 / E1≦0.3. In another embodiment, E2 / E1≧0.01. A too low value may not provide enough luminescent material light when using the second light-generating device. A too high value may not provide a wide CCT tunability.

[0127] The luminescent material may be configured in the reflection mode or in the transmission mode. In the transmission mode, it may be relatively easy to mix the source light into the luminescent material light. This may be useful for generating a desired spectral power distribution. In the reflection mode, thermal management may be easier since a significant portion of the luminescent material may be in thermal contact with a thermally conductive element such as a heat sink or heat spreader. In the reflection mode, a portion of the source light may be reflected by the luminescent material and / or a reflector in embodiments and mix with the luminescent material light. The reflector may be configured downstream of the luminescent material (in the reflection mode).

[0128] The thermally conductive element may in particular comprise a thermally conductive material. The thermally conductive material may in particular have a thermal conductivity of at least about 20 W / (m×K), such as at least about 30 W / (m×K), such as at least about 100 W / (m×K), in particular at least about 200 W / (m×K). In yet other particular embodiments, the thermally conductive material may in particular have a thermal conductivity of at least about 10 W / (m×K). In embodiments, the thermally conductive material may comprise one or more of copper, aluminum, silver, gold, silicon carbide, aluminum nitride, boron nitride, aluminum silicon carbide, beryllium oxide, silicon carbide composite, aluminum silicon carbide, copper tungsten alloy, copper molybdenum carbide, carbon, diamond, and graphite. Alternatively or in addition, the thermally conductive material may comprise or consist of aluminum oxide.

[0129] The thermally conductive element may comprise a heat sink. Heat sinks are known in the art. The term "heat sink" (or heat sink) may in particular be a passive heat exchanger that transfers heat generated by a device, such as an electronic or mechanical device, to a fluid (cooling) medium, often air or a cooling liquid. Thereby, the heat is (at least partially) dissipated away from the device. A heat sink is in particular designed to maximize the surface area of ​​the heat sink in contact with the fluid cooling medium surrounding the heat sink. Thus, in particular, the heat sink may comprise a number of fins. For example, the heat sink may be a body from which a number of fins extend. A heat sink in particular comprises (more in particular consists of) a thermally conductive material. The term "heat sink" may also refer to a number of (different) heat sinks. The thermally conductive element may comprise a heat spreader. The heat spreader may be configured to transfer energy as heat from a first element to a second element. The second element may in particular be a heat sink or a heat exchanger. The heat spreader may be passive or active. An embodiment of a passive heat spreader may comprise a plate or block of a material with high thermal conductivity, such as copper, aluminum or diamond. An active heat spreader may be configured to accelerate the heat transfer by consuming energy as work provided by an external source. In the present specification, the heat spreader may in particular be a passive heat spreader. Alternatively or additionally, the heat spreader may be an active heat spreader, such as selected from the group of heat pipes and vapor chambers. The heat spreader in particular comprises (more in particular consists of) a thermally conductive material. The term "heat spreader" may also refer to a plurality of (different) heat spreaders.

[0130] In embodiments, the luminescent material, such as a luminescent body, may be in thermal contact with the thermally conductive material, such as a thermal conductor. Instead of the term "thermal contact" and similar terms, the term "thermally coupled" or similar terms may also be applied.

[0131] An element may be considered to be in thermal contact with another element if the element is capable of exchanging energy through a thermal process. The elements may therefore be thermally coupled. In an embodiment, thermal contact may be achieved by physical contact. In an embodiment, thermal contact may be achieved via a thermally conductive material, such as a thermally conductive adhesive. Thermal contact between two elements may also be achieved if the two elements are disposed at a distance of about 10 μm or less relative to each other, although larger distances, such as up to 100 μm, may be possible. The shorter the distance, the better the thermal contact. In particular, the distance is 10 μm or less, such as 1 μm or less, such as 5 μm or less. The distance may be the distance between two respective surfaces of each element. The distance may be an average distance. For example, the two elements may be in physical contact at one or more locations, such as a plurality of locations, while at one or more, particularly a plurality of, other locations the elements are not in physical contact. This may be the case, for example, if one or both elements have a rough surface. Thus, in an embodiment, the distance between the two elements may be, on average, 10 μm or less (although a larger average distance, such as up to 100 μm, may be possible). In an embodiment, the two surfaces of the two elements may be kept at a distance by one or more distance holders. When the two elements are in thermal contact, they may be in physical contact or may be arranged at a small distance, such as up to 1 mm, such as up to 10 μm, from each other. When the two elements are arranged at a distance from each other, an intermediate material may be arranged between them, but in other embodiments, the distance between the two elements may be filled with a gas, liquid, or may be a vacuum. If an intermediate material is available, the greater the distance, the higher the thermal conductivity available for the thermal contact between the two elements may be. However, the smaller the distance, the lower the thermal conductivity of the intermediate material may be (although of course higher thermally conductive materials may also be used).

[0132] For the reflective mode, in embodiments, a portion of the first device light may be directed to the luminescent material and a portion of the first device light may bypass the luminescent material. Similarly, for the reflective mode, in embodiments, a portion of the second device light may be directed to the luminescent material and a portion of the second device light may bypass the luminescent material. In embodiments, for the transmissive mode, a portion of the first device light and / or a portion of the second device light may be directed to the luminescent material and a portion of the first device light and / or a portion of the second device light may bypass the luminescent material.

[0133] When pump light may have a spectral power distribution that may be used both for pumping the luminescent material and for mixing into the system light, several options may be chosen. In an embodiment, multiple first light-generating devices may be applied, one or more being used to pump the luminescent material and one or more other first light-generating devices being configured to provide a first device light that bypasses the luminescent material. Alternatively or in addition, one or more first light-generating devices may be used to generate a first device light, a part of which may be directed to the luminescent material and another part of which may be configured to bypass the luminescent material. This may be done, for example, via a beam splitter. Light may bypass the luminescent material when it is not illuminating the luminescent material (in transmission or reflection mode).

[0134] In the reflective mode, a dichroic reflector may be used to promote the luminescent material light over the (first and / or second) device light, which may be transmitted with a higher transmission factor than the (first and / or second) device light, and which may be reflected with a higher reflection factor than the luminescent material light.

[0135] Thus, in a particular embodiment, the light generation system may further comprise a dichroic element configured to transmit or reflect the (first and / or second) device light and configured to reflect or transmit the luminescent material light. The dichroic element may be an embodiment of a color separation element as described in US7070300, which is incorporated herein by reference. In particular, the color separation element may be selected from the group of a dichroic mirror, a dichroic cube, and a diffractive optical element. Optionally, the color separation element may be provided using a hologram. In particular, the dichroic element may be a dichroic mirror or a reflector.

[0136] Thus, in an embodiment, the (white) system light may comprise the first device light, the second device light, the luminescent material light, and optionally the third device light, the first device light being provided by one or more first light generating devices configured to generate first device light that at least in part bypasses the luminescent material.

[0137] In embodiments good results may be obtained with a first luminescent material light having a dominant wavelength selected from the range of about 562-582 nm, such as a dominant wavelength selected from the range of 563-580 nm. In particular, the luminescent material light may have a dominant wavelength selected from the range of 565-577 nm. Even more particularly, the luminescent material light may have a dominant wavelength selected from the range of 567-577 nm.

[0138] For transmission mode use and / or thermal management and / or robustness considerations, the luminescent material may be comprised in a single crystal or a ceramic body. Thus, the system may comprise a single crystal that comprises (or is) the luminescent material. Alternatively or in addition, the system may comprise a ceramic body that comprises (or is) the luminescent material.

[0139] Ceramic bodies are known in the art. In particular, said ceramic materials may be obtained by sintering and / or hot pressing, optionally followed by annealing in a (slightly) oxidizing atmosphere. The term "ceramic" refers in particular to inorganic materials, especially those made of 10 -8It relates to an inorganic material obtained by heating a (polycrystalline) powder at a temperature of at least 500°C, in particular at least 800°C, such as at least 1400°C, such as at least 1000°C, under reduced, atmospheric or elevated pressure, in particular under uniaxial or isostatic pressure, in particular under isostatic pressure, such as in the range of 1000 to 500 MPa, in particular at least 0.5 MPa, in particular at least 1 MPa, such as 1 to about 500 MPa, at least 5 MPa, or at least 10 MPa. A particular method for obtaining the ceramic is hot isostatic pressing (HIP), which HIP treatment may be a post-sintering HIP, capsule HIP or compound sintering HIP treatment, such as under temperature and pressure conditions as mentioned above. The ceramic obtained by such a method may be used as it is or may be further treated (such as polished). The ceramic has a density that is in particular at least 90% (or more, see below), such as in the range of 97 to 100%, such as at least 95%, of the theoretical density (i.e. the density of a single crystal). The ceramic may still be polycrystalline, but the volume between the grains (compressed grains or compressed agglomerates) is reduced or greatly reduced. Heating at high pressure, such as HIP, may be carried out in an inert gas, such as, for example, one or more of N2 and argon (Ar). In particular, the heating at high pressure is preceded by a sintering treatment at a temperature selected from the range of 1400-1900°C, such as 1500-1800°C. Such sintering may be carried out at temperatures of 1000°C to 1900°C. -2The sintering may be carried out under reduced pressure, such as a pressure of 0.1 Pa or less. Such sintering may already result in a density of the order of at least 95%, even more particularly at least 99%, of the theoretical density. After both pre-sintering and heating, particularly under high pressure, such as HIP, the density of the optically transparent body may be close to that of a single crystal. The difference, however, is that since the optically transparent body is polycrystalline, grain boundaries are available in the optically transparent body. Such grain boundaries can be detected, for example, by optical microscopy or SEM. Thus, in the present specification, the optically transparent body refers in particular to a sintered polycrystal having substantially the same density as a single crystal (of the same material). Thus, such an optically transparent body can be obtained by sintering a sintered polycrystal (particularly Ce). 3+ They may be highly transparent to visible light (except for absorption by light absorbing species such as ZnO, ZnSe, etc.).

[0140] Thus, in a particular embodiment, the luminescent material light may have a dominant wavelength selected from the range of 567-577 nm, the light generation system may comprise a ceramic body, the ceramic body comprising the luminescent material, the luminescent material may be operated in the reflection mode, the ceramic body may have at least one surface thermally coupled to a heat conductor, in particular a reflective heat conductor, the light generation system may further comprise an optical element arranged downstream of the luminescent material, the optical element being reflective to the first device light and transparent to the luminescent material light. As mentioned above, the optical element may comprise a dichroic mirror. Furthermore, the reflective heat conductor may be reflective at least to the first device light. Furthermore, the reflective heat conductor may be reflective to the second device light. The reflective heat conductor may also be reflective to the luminescent material light. The heat conductor may be reflective itself or may have a reflective coating.

[0141] As noted above, the luminescent material may be contained in a body. Such a body may be referred to as a "transducer body" or a "luminescent body." In embodiments, the luminescent body may be a luminescent single crystal or a luminescent ceramic body.

[0142] In an embodiment, the transducer body ("body") may have a lateral dimension, such as a width or length (W1 or L1) or a diameter (D1), and a thickness or height (H1). The length or the width or the diameter is denoted a transducer body dimension. The term transducer body dimension is used specifically with respect to the width or length (W1 or L1) or the diameter (D1), although the thickness or the height may also be considered a transducer body dimension. These transducer body dimensions may be significantly larger than the thickness or the height (H1). Thus, the transducer body may have one or more transducer body dimensions (D) defined perpendicular to the transducer body height (H1).

[0143] In embodiments, (i) D1≧H1, or (ii) W1≧H1 and / or L1≧H1. In certain embodiments, L1≦100mm, especially L1≦60mm, more especially L1≦50mm, and most especially L1≦40mm. In certain embodiments, W1≦100mm, especially W1≦60mm, more especially W1≦50mm, and most especially W1≦40mm.

[0144] In certain embodiments, H1≦1 mm, such as H1≦0.5 mm, more particularly selected from the range of 5 to 500 μm, such as selected from the range of 50 to 500 μm, such as selected from the range of 100 to 300 μm.

[0145] In particular embodiments, D1≦100 mm, such as D1≦60 mm, more particularly D1≦50 mm, and most particularly D1≦40 mm. Furthermore, the body may have a lateral dimension (width / diameter) in the range of 500 μm to 100 mm, such as 0.1 to 40 mm. In yet other particular embodiments, (i) D1≧H1, or (ii) W1≧H1 and W1≧H1. In particular, the lateral dimensions, such as length, width and diameter, are at least twice as large as the height, such as at least five times. In particular embodiments, the transducer body has a first length L1, a first height H1 and a first width W1, with H1≦0.5×L1 and H1≦0.5×W1. The transducer body may thus have a tile shape. The transducer body may have a rectangular or circular cross section, although other cross sections may be possible. In an embodiment, the height of the transducer body may be selected from the range of 50 to 500 μm, such as for example 100 to 300 μm.

[0146] In particular, in certain embodiments, the one or more transducer body dimensions (D) may be selected from the range of 0.1 to 40 mm. In certain embodiments, H1 / D1≦0.5. Furthermore, in embodiments, the one or more transducer body dimensions (D) may be selected from the range of 0.1 to 30 mm, such as 0.1 to 20 mm, in certain embodiments, such as 0.1 to 10 mm, such as at least 0.2 mm, such as at least 2 mm. Thus, in embodiments, the thickness of the luminescent body may be in the range of 100 μm to 300 μm.

[0147] An optical system may be configured downstream of the luminescent material and the first and second devices, and optionally the third device, such that in embodiments system light may only escape the system via such an optical system.

[0148] The term "optical system" may refer in particular to (one or more) optical elements. Thus, the terms "optical system" and "optical element" may refer to the same thing. The optical system may include one or more of mirrors, reflectors, collimators, lenses, prisms, diffusers, phase plates, polarizers, diffractive elements, diffraction gratings, dichroics, arrays of one or more of the foregoing, etc. Alternatively or in addition, the term "optical system" may refer to a holographic element or a mixing rod. In an embodiment, the optical system may include one or more of beam expander optics and zoom lens optics. In an embodiment, the optical system may include an integrator, such as a "Köhler integrator" (or "Köhler integrator"). In particular, the optical system may be used for beam shaping and / or light mixing of the first device light, the second device light, the luminescent material light, and optionally the third device light.

[0149] In certain embodiments, the system includes only a laser as a light generating device. In certain embodiments, the system includes only a first light generating device, a second light generating device, and a third light generating device (including, of course, the luminescent material) as light generating devices. In embodiments, each of the first light generating device, the second light generating device, and the third light generating device may be a laser light source.

[0150] In certain embodiments, for example, a compact package may be provided. For example, in embodiments, the system may include an integrated light source package, the integrated light source package including a common support member configured to support the first light generating device, the second light generating device, the third light generating device, and the luminescent material, the common support member including a thermally conductive support. The thermally conductive support may include one or more of a heat sink, a heat spreader, and a vapor chamber.

[0151] In an embodiment, the first light-generating device and the second light-generating device are configured to provide the device light at an angle with a face of the luminescent body, such as an angle of between 30 and 85°.

[0152] The light generating system may be part of or used in, for example, an office lighting system, a home application system, a shop lighting system, a domestic lighting system, an accent lighting system, a spot lighting system, a theatre lighting system, a fiber optic application system, a projection system, a self-lit display system, a pixelated display system, a segmented display system, a warning sign system, a medical lighting application system, an indicator sign system, a decorative lighting system, a portable system, an automotive application, an (outdoor) road lighting system, an urban lighting system, a greenhouse lighting system, a horticultural lighting, digital projection, or an LCD backlight. The light generating system (or the luminaire) may be part of or used in, for example, an optical communication system or a disinfection system.

[0153] In yet another aspect, the present invention also provides a lamp or luminaire having a light generation system as defined herein. The luminaire may further comprise a housing, optical elements, louvers, etc. The lamp or luminaire may further comprise a housing enclosing the light generation 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 another aspect, the present invention also provides a projection device having a light generation system as defined herein. In particular, a projection device or "projector" or "image projector" may be an optical device that projects an image (or a moving image) onto a surface, such as a projection screen. The projection device may include one or more light generation systems as described herein. Thus, the present invention also provides, in one aspect, an illumination device selected from the group of lamps, luminaires, projector devices, disinfection devices, photochemical reactors, and optical wireless communication devices, the illumination device having a light generation system as defined herein. The lighting device may have a housing configured to accommodate or a carrier configured to support one or more elements of the light generation system, for example in embodiments the lighting device may have a housing configured to accommodate or a carrier configured to support one or more of the first light generating device, the second light generating device, optionally the third light generating device, etc.

[0154] 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. In this specification, UV may refer in particular to wavelengths selected from the range of 190-380 nm, such as 200-380 nm. In this specification, the terms "light" and "radiation" are used interchangeably, unless it is clear from the context that the term "light" refers only to visible light. Thus, the terms "light" and "radiation" may refer to UV radiation, visible light, and IR radiation. In certain embodiments, particularly for lighting applications, the terms "light" and "radiation" refer to (at least) visible light. The terms "upstream" and "downstream" refer to the location of an item or feature with respect to the propagation of light from a light generating means (here, particularly the light source), such that with respect to a first location in a light beam from the light generating means, a second location in the light beam closer to the light generating means is "upstream" and a third location in the light beam further away from the light generating means is "downstream". [Brief description of the drawings]

[0155] Embodiments of the present 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, in which: [Figure 1] Some examples and results are given. [Diagram 2] Some examples and results are given. [Diagram 3] Some examples and results are given. [Figure 4] Some examples and results are given. [Diagram 5] Some examples and results are given. [Figure 6] Some examples and results are given. [Figure 7] Some examples and results are given. [Figure 8] Some examples and results are given. [Figure 9a] Several aspects and embodiments are illustrated diagrammatically. [Figure 9b]Several aspects and embodiments are illustrated diagrammatically. [Figure 9c] Several aspects and embodiments are illustrated diagrammatically. [Figure 10] Several application embodiments are illustrated diagrammatically.

[0156] The schematic drawings are not necessarily to scale. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0157] It is proposed herein, inter alia, to use a configuration in which blue lasers with two different wavelengths are used to excite the blue phosphor. A third red laser may also be combined to produce a wide range BBL dimmable high intensity white light source. The light source may be arranged to operate in a transmission mode (passing through the luminescent material, such as a ceramic luminescent body) or in a reflection mode (partially reflected at the luminescent material, such as a ceramic luminescent body) so that a well-mixed white light is obtained. The first blue light may be, for example, in the range of 450-470 nm and may be absorbed to a greater extent than the second blue light by the luminescent material, such as a ceramic luminescent body. The second blue light may be, for example, in the range of 420-450 nm or 470-490 nm and may be absorbed to a lesser extent than the first blue light by the luminescent material, such as a ceramic luminescent body. In particular, the peak difference between the blue lights used may be at least 10 nm. The peak wavelength of the red light may be, for example, in the range of 610-640 nm. The dominant wavelength of the emission from the luminescent material, such as the ceramic luminescent body, may be in the range of 565 to 577 nm, such as 567 to 577 nm, in particular in the wavelength range of 450 to 470 nm, and may be 0.85 or greater.

[0158] In the present specification, in an embodiment, the use of a garnet phosphor in reflection or transmission mode is proposed, with two blue lasers emitting at two different wavelengths that can be absorbed to different degrees by the ceramic phosphor. Figures 1 and 2 show (a) the absorbance (Figure 1) and transmittance (Figure 2) of a 150 micron thick transparent sample (0.2% Ce) Ce:YAG sample as a function of wavelength. Samples with higher concentrations up to 0.8% Ce (i.e. up to 0.8 at.% Ce for "A", see also above). In these figures, the dependence of absorbance on Ce concentration is also shown for the transparent ceramic garnet sample.

[0159] The excitation spectrum at the emission maximum, e.g., 567-577 nm, may be substantially the same as, or at least have a corresponding shape to, the absorption spectrum of Figure 1. The absorbance and excitation spectra of various cerium comprising garnets, and all other types of luminescent materials, are known in the art.

[0160] 1, at 0.8% Ce (i.e., 0.8 at.% Ce), the ratio of absorbance E1 at about 465 nm to absorbance E2 at, for example, about 430 nm may be about 1.8:0.9. Thus, in this example, TIFF2025501774000002.tif829. E1 is indicated by the higher horizontal dashed dotted line that blocks absorption at about 465 nm, and E2 is indicated by the lower horizontal dashed dotted line that blocks absorption at about 430 nm.

[0161] In Fig. 2 (and also substantially in Fig. 1), it can be seen that in the wavelength range 450-470 nm, especially at higher cerium concentrations, the peak transmission flattens out, and a sharp increase in transmission is observed in the wavelength ranges 420-450 nm and 470-490 nm (corresponding to either side of the peak). To achieve BBL tuning in a wide temperature range, it may be desirable to have a small amount of blue in the garnet emission in order to have a color point close to the dominant wavelength of the phosphor. This may mean that the peak absorbance (450-470 nm) may be higher than about 0.85. In the wavelength ranges 420-450 nm and 470-490 nm, the choice of wavelength may determine to what extent blue light is absorbed and in which wavelength ranges the BBL is followed.

[0162] In the example shown in FIG. 3, color tuning using two blue wavelengths is illustrated diagrammatically. If we assume for example the use of a garnet containing cerium, the dominant wavelength of such a material may be, for example, about 570 nm. If we assume the use of a light generating device with a peak wavelength of 430 nm for the low wavelength blue and a light generating device with a peak wavelength of 465 nm for the high wavelength blue, then all color points along the line connecting these two points can be obtained. If these wavelengths used to pump the garnet are combined with red light with a peak wavelength of, for example, 620 nm, then any color point within the triangle connecting all these three color points can be obtained. Considering that part of the BBL is also within this region, this means that color points that are on the BBL segment within this region can also be generated. This means that with these three wavelengths, BBL dimming can be realized between CCT=2000K and CCT=6000K. This is illustrated diagrammatically in FIG. 3.

[0163] In Figure 4 essentially the same applies as above but using light generating devices with peak wavelengths of 477 nm and 452 nm for example. It can be seen that the range of the BBL can be limited to about 2000-3000 K. The colour points shown for YAG refer to the emission of only the garnet-based luminescent material.

[0164] In particular, the color point of a garnet with an absorbance of 0.95 at 465 nm was calculated. Figure 5 shows the color points of lasers emitting at various wavelengths. From this figure it can be seen that if a garnet excited at about 465 nm is combined with an absorbance of 445 nm, a BBL dimming between 6000K and 3000K can be obtained. If a laser with an emission of 430 nm is used instead of a 445 nm laser, the BBL dimming can still be between about 6000K and 3000K, and even off-BBL dimming can be performed up to about 20000K.

[0165] Additionally, modelling of a garnet with an absorbance of 1.27 at 465 nm and an absorbance of 430 nm was applied, and when lasers with these wavelengths are used in combination with a 625 nm laser, it appears possible to achieve BBL dimming between approximately 2000K and 6000K.

[0166] 6-7, 430 nm, 465 nm and 625 nm emissions are provided, for example, via a laser, and the absorbance at 430 nm is A=0.15 and at 465 nm is A=1.27. In FIG. 6, color points at various intensity ratios of 465 nm and 430 nm are shown. Here, it can be seen that BBL dimming is possible even below 6000K. FIG. 7 shows the emission spectrum for CCT=3000K. Reference 121 denotes a second device light with a peak wavelength λ2, reference 111 denotes a first device light with a peak wavelength λ1, reference 131 denotes a third device light with a peak wavelength λ3, reference 201 denotes a centroid wavelength λ4, reference 202 denotes a second device light with a peak wavelength λ5, reference 203 denotes a third device light with a peak wavelength λ6, reference 204 denotes a second device light with a peak wavelength λ7, reference 205 denotes a third device light with a peak wavelength λ8, reference 206 denotes a third device light with a peak wavelength λ9, reference 207 denotes a fourth device light with a peak wavelength λ10, reference 208 denotes a fourth device light with a peak wavelength λ11, reference 209 denotes a fifth device light with a peak wavelength λ22, reference 210 denotes a fifth device light with a peak wavelength λ11, reference 211 denotes a fifth device light with a peak wavelength λ12, reference 212 denotes a fifth device light with a peak wavelength λ13, reference 213 denotes a fifth device light with a peak wavelength λ14, reference 214 denotes a fifth device light with a peak wavelength λ15, reference 215 denotes a fifth device light with a peak wavelength λ16, reference 216 denotes a fifth device light with a peak wavelength λ17, reference 218 denotes a fifth device light with a peak wavelength λ18, reference 219 denotes a fifth device light c,1 The dashed line shows the spectral power distribution of a blackbody radiator at 3000K.

[0167] The table below lists the characteristics of the above white lights, and shows that for all CCTs, the CRI does not reach 90.

[0168] [Table 1]

[0169] In the alternative, the wavelengths were 430 nm, 465 nm and 625 nm, but the absorbance at 465 nm was A=0.95 and the absorbance at 430 nm was A=0.25. In Fig. 8 the color points are shown for various intensity ratios of 430 nm and 465 nm light. Here, as expected, it can be seen that BBL dimming is possible above 6000K. However, due to the lower absorbance, it is not possible to lower the CCT below about CCT=3000K.

[0170] The table below lists the properties of the above mentioned lights. This garnet phosphor with absorbance at 465 nm has a CRI of 93 at CCT=3000K, although no CCT tuning is possible below CCT=3000K.

[0171] [Table 2]

[0172] In another simulation, 440 nm, 465 nm, 625 nm, and absorbance A=0.57 at 440 nm and A=0.95 at 465 nm were applied. As expected, BBL dimming is possible above 6000 K. However, due to the lower absorbance, it is not possible to lower the CCT below about CCT=3000 K.

[0173] The table below lists the properties of the above mentioned lights. For this garnet phosphor with absorbance at 465 nm, a CRI of 93 is obtained at CCT=3000K, although the CCT tuning falls within a smaller range.

[0174] [Table 3]

[0175] In another simulation, 477 nm, 452 nm, and 620 nm emission sources were used, and the absorbance at 452 nm was A=1.27 and at 477 nm was A=0.75. As expected, the BBL range is relatively small. To obtain a wider CCT range, the second device light should be in the lower wavelength range, e.g., 420-450 nm.

[0176] The table below shows the characteristics of the light that can be produced by it.

[0177] [Table 4]

[0178] In the table below the effect of a red laser on the various properties is shown with absorbance at 430nm and 465nm, contribution at 625nm, A=0.33 at 430nm and A=1.27 at 465nm at a CCT of 3000K.

[0179] [Table 5]

[0180] Referring to Figures 9a to 9c, an embodiment of a light generation system 1000 is illustrated generally comprising a first light generation device 110, a second light generation device 120, an optional third light generation device 130, a luminescent material 200 and an optional control system 300.

[0181] The first light-generating device 110 may comprise a laser light source and may be configured to generate a first device light 111 having a first device peak wavelength λ1 and a first spectral power distribution. The first device peak wavelength λ1 may be selected from the wavelength range of 445 to 475 nm. The first device peak wavelength λ1 may in particular be selected from the wavelength range of 450 to 470 nm.

[0182] The second light generating device 120 may comprise a laser light source and may be configured to generate a second device light 121 having a second device peak wavelength λ2 and a second spectral power distribution different from the first spectral power distribution. The second device peak wavelength λ2 may be selected from the range of 420-450 nm or the range of 470-490 nm.

[0183] The luminescent material 200 may be excitable by the first device light 111 and the second device light 121. The luminescent material 200 may emit at least a portion of one or more of the first device light 111 and / or the second device light 121 at a centroid wavelength λ λ 2 within the green-orange wavelength range. c,1to a luminescent material light 201 having a dominant wavelength selected from the range 565 to 577 nm, such as 562 to 582 nm, in particular 567 to 577 nm. The luminescent material 200 has an absorbance band having a first absorbance E1 at a first device peak wavelength λ1 and a second absorbance E2 at a second device peak wavelength λ2. In particular, E2 / E1<1. The luminescent material light 201 may have a dominant wavelength selected from the range 565 to 577 nm, such as 562 to 582 nm, in particular 567 to 577 nm.

[0184] The third light generating device 110 may comprise a laser light source and may be configured to generate a third device light 111 having a third device peak wavelength λ3 selected from the wavelength range of 600 to 650 nm. The third device peak wavelength (λ3) may in particular be selected from the wavelength range of 610 to 640 nm.

[0185] In particular, |λ1-λ2|≧20 nm. In an embodiment, λ1 and λ2 are selected from the wavelength range of 420 to 490 nm. Further, in an embodiment, |λ c,1 −λ3|≧30 nm.

[0186] The control system 300 may be configured to control at least the first light-generating device 110 and the second light-generating device 120 .

[0187] In an operational mode, the light-producing system 1000 may be configured to provide white system light 1001 .

[0188] The luminescent material 200 is A3B5O 12 % cerium. In an embodiment, luminescent material 200 may comprise a C(0.5-0.25) type luminescent material, where A may comprise one or more of Y, La, Gd, Tb, and Lu, and B may comprise one or more of Al, Ga, In, and Sc. In an embodiment, A may comprise at least 50 at.% Lu, and B may comprise at least 90 at.% Al. In an embodiment, luminescent material 200 may comprise 0.5-2 at.% cerium with respect to A.

[0189] In an embodiment, the first light-generating device 110 and the second light-generating device 120 may be arranged in a single laser bank 500.

[0190] Also, referring to FIG. 9c, E2 / E1≦0.5 or E2 / E1≦0.3.

[0191] The luminescent material 200 may be operated in a reflective mode (see FIG. 9b) or a transmissive mode (see FIG. 9a).

[0192] The ceramic body 210 may have at least one surface that is thermally coupled to a reflective thermal conductor 510. The reflective thermal conductor 510 may be reflective to at least the first device light 111.

[0193] The light generation system 1000 may further comprise an optical element 410 configured downstream of the luminescent material 200. The optical element 410 may be reflective to the first device light 111 and transmissive to the luminescent material light 201.

[0194] The optical element 420 may be, for example, a beam shaping optic or a light mixing optic.

[0195] The (beam-shaping) optical element may in particular comprise a collimator that is used to convert (to "collimate") the light beam (to be (further) beam-shaped) into a beam with a desired angular distribution. In an embodiment, the (beam-shaping) optical element may in particular comprise an optically transparent body. Thus, the (beam-shaping) optical element may be a body of optically transparent material configured to collimate the light beam (to be (further) beam-shaped). In a particular embodiment, the (beam-shaping) optical element comprises a compound parabolic collimator, such as a CPC (compound parabolic concentrator). A large collimator, such as a large CPC, may in particular be used as an extractor of the light (to be (further) beam-shaped) and to collimate the light (to be (further) beam-shaped). Alternatively or in addition, one or more lenses may be used to beam-shape the light (to be (further) beam-shaped). In this manner, the device light may be beam-shaped. The optical element may have a beam-shaping function. Alternatively or additionally, the optical element may have a homogenization and / or mixing function. This may be the case especially when using a concentrator, such as a CPC.

[0196] The control system 300 may be configured to control the spectral power distribution of the system light 1001. The control system 300 may be configured to control the correlated color temperature of the system light 1001 to a value selected from the range of 1800 to 6500K. The correlated color temperature of the system light 1001 may be controllable over a CCT control range of at least 500K within the range of 1800 to 6500K. The correlated color temperature of the system light 1001 may be controllable over a CCT control range of at least 1000K within the range of 2000 to 6000K. The control system 300 may be configured to control the R9 value of the system light 1001 to a value of at least 30. The R9 value of the system light 1001 may be controllable over an R9 control range of at least 30. The R9 control range at least partially overlaps with the range of at least 30. The color rendering index of the system light 1001 may be at least 80.

[0197] Fig. 10 illustrates diagrammatically an embodiment of a luminaire 2 including a light-generating system 1000 as described above. Reference number 301 indicates a user interface that may be functionally associated with a control system 300 included by or functionally associated with the light-generating system 1000. Fig. 10 also illustrates diagrammatically an embodiment of a lamp 1 including the light-generating system 1000. Reference number 3 indicates a projector device or projector system that may be used to project an image onto a wall or the like, said projector device or projector system may also include the light-generating system 1000. Thus, Fig. 10 illustrates diagrammatically an embodiment 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 a light-generating system 1000 as described herein. In an embodiment, such a lighting device may be a lamp 1, a luminaire 2, a projector device 3, a disinfection device, or an optical wireless communication device. Illumination device light escaping from the illumination device 1200 is indicated with reference number 1201. The illumination device light 1201 may essentially consist of the system light 1001 and therefore may in certain embodiments be the system light 1001. Reference number 1300 refers to space.

[0198] The term "plurality" refers to two or more.

[0199] The terms "substantially" or "essentially" and similar terms herein will be understood by those of skill in the art. The terms "substantially" or "essentially" may also include embodiments with "entirely," "completely," "all," and the like. Thus, in embodiments, the adjectives substantially or essentially may be omitted. Where applicable, the terms "substantially" or "essentially" may also relate to 90% or more, including 100%, such as 95% or more, particularly 99% or more, and even more particularly 99.5% or more.

[0200] The term "comprises" also includes embodiments in which the term "comprises" means "consisting of."

[0201] The term "and / or" specifically refers to one or more of the items mentioned before and after "and / or." For example, the phrase "item 1 and / or item 2," and similar phrases, can refer to one or more of item 1 and item 2. The term "comprising" can refer in some embodiments to "consisting of," while in other embodiments it can refer to "including at least the specified species, and optionally one or more other species."

[0202] Moreover, in the specification and claims, the terms first, second, third, etc. are used to distinguish between similar elements and are not necessarily used to describe a sequential or chronological order. The terms so used are interchangeable under appropriate circumstances, and it is to be understood that the embodiments of the invention described herein are capable of operation in orders other than those described or illustrated herein.

[0203] The present specification may describe, among other things, devices, apparatus, or systems in operation. As will be apparent to one of ordinary skill in the art, the present invention is not limited to methods of operation or devices, apparatus, or systems in operation.

[0204] It should be noted that the above-described embodiments are illustrative of the invention rather than limiting, and that those skilled in the art will be able to design many other embodiments without departing from the scope of the appended claims.

[0205] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

[0206] The use of the verb "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 specification and claims, words like "comprise" and the like should be interpreted in their inclusive sense, i.e., "including, but not limited to," as opposed to their exclusive or exhaustive sense.

[0207] The singular reference of an element does not exclude the presence of a plurality of such elements.

[0208] The invention may be implemented by means of hardware comprising several distinct elements, or 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 means are recited in mutually different dependent claims does not indicate that a combination of these means cannot be used to advantage. (Thus) in yet another aspect, the invention provides software which, when executed on a computer, is capable of implementing (one or more embodiments of) the method as described herein.

[0209] The present invention also provides a control system that may control a device, apparatus or system or that may perform the methods or processes described herein. Still further, the present invention also provides a computer program product that, when executed on a computer operatively coupled to or included in a device, apparatus or system, controls one or more controllable elements of such a device, apparatus or system.

[0210] The invention further applies to a device, an apparatus or a system having one or more of the characterizing features described in the specification and / or shown in the accompanying drawings.The invention further relates to a method or process having one or more of the characterizing features described in the specification and / or shown in the accompanying drawings.

[0211] Various aspects described in this patent can be combined to provide additional advantages. Moreover, those skilled in the art will appreciate that embodiments can be combined, and that more than two embodiments can be combined. Furthermore, some of the features can form the basis for one or more divisional applications.

Claims

1. 1. A light-generating system comprising a first light-generating device, a second light-generating device, a third light-generating device, a luminescent material, and a control system, The first light-generating device has a first laser light source and a first device peak wavelength λ １ and configured to generate first device light having a first spectral power distribution, the first device peak wavelength λ １ is selected from the wavelength range of 445 to 475 nm; The second light generating device has a second laser light source and a second device peak wavelength λ ２ and configured to generate second device light having a second spectral power distribution different from the first spectral power distribution, and the second device peak wavelength λ ２ is selected from the range of 470 to 490 nm, The luminescent material is excitable by the first device light and the second device light, and the luminescent material emits at least a portion of the first device light and the second device light at a centroid wavelength λ 1 within a green to orange wavelength range. ｃ，１ and the luminescent material is configured to convert light having the first device peak wavelength λ １ and the second device peak wavelength λ ２ and the luminescent material comprises an A3B5O12:Ce type luminescent material, wherein A comprises one or more of Y, La, Gd, Tb, and Lu, and B comprises one or more of Al, Ga, In, and Sc; The third light-generating device has a third laser light source and a third device peak wavelength λ selected from the wavelength range of 600 to 650 nm. ３ a third device configured to generate light having a |λ １ -λ ２ |≧20 nm, and |λ ｃ，１ -λ ３ |≧20 nm, the control system is configured to control at least the first light-generating device and the second light-generating device; the light-producing system is configured, in an operational mode, to provide white system light; 1. A light generating system, wherein the control system is configured to control a spectral power distribution of the system light, and wherein the control system is configured to control a correlated color temperature of the system light to a value selected from a range of 1800 to 6500 K, and wherein the correlated color temperature of the system light is controllable over a CCT control range of at least 500 K within the range of 1800 to 6500 K.

2. The luminescent material is ３ B ５ O １２ 10. The light-generating system of claim 1, comprising a luminescent material of the Ce type, wherein A comprises one or more of Y, Gd and Lu, and B comprises one or more of Al and Ga.

3. 3. The light-generating system of claim 2, wherein A comprises at least 50 at. % Lu and B comprises at least 90 at. % Al.

4. 3. The light-generating system of claim 2, wherein the luminescent material comprises 0.1 to 2 at. % cerium relative to A.

5. the first device peak wavelength λ １ 3. The light-generating system of claim 1 or 2, wherein is selected from the wavelength range of 450 to 470 nm.

6. 3. The light generating system of claim 1 or 2, wherein the correlated color temperature of the system light is controllable over a CCT control range of at least 1000K within the range of 1800 to 6500K.

7. the second device peak wavelength λ ２ 3. The light-generating system of claim 1 or 2, wherein the wavelength is selected from the range of 470 to 480 nm.

8. 3. The light-generation system of claim 1 or 2, wherein the first light-generating device and the second light-generating device are arranged in a single laser bank.

9. A light generating system as claimed in claim 1 or 2, wherein the luminescent material further comprises one or more luminescent materials such as MS:Eu 2+ and / or M 2 Si 5 N 8 :Eu 2+ and / or MAlSiN 3 :Eu 2+ and / or Ca 2 AlSi 3 O 2 N 5 :Eu 2+ , wherein M comprises one or more of Ba, Sr and Ca.

10. The light generating system of claim 1 or 2, wherein 0.01≦E2 / E1≦0.

3.

11. Third device peak wavelength λ ３ 3. The light-generating system of claim 1 or 2, wherein is selected from the wavelength range of 620 to 640 nm.

12. 3. The light-generation system of claim 1, wherein the luminescent material light has a dominant wavelength selected from the range of 565 to 577 nm, the light-generation system comprising a ceramic body comprising the luminescent material, the luminescent material being operated in a reflective mode, the ceramic body having at least one surface thermally coupled to a reflective heat conductor, the reflective heat conductor being reflective to at least the first device light, and the light-generation system further comprising an optical element configured downstream of the luminescent material, the optical element being reflective to the first device light and transparent to the luminescent material light.

13. 3. The light generating system of claim 1, wherein the control system is configured to control a spectral power distribution of the system light, and wherein the control system is configured to control the correlated color temperature of the system light to a value selected from a range of 2700 to 4000 K, and wherein the correlated color temperature of the system light is controllable over a CCT control range of at least 500 K within the range of 2700 to 4000 K.

14. 3. The light generating system of claim 1 or 2, wherein the control system is configured to control the R9 value of the system light to a value of at least 30, and wherein the color rendering index of the system light is at least 80.

15. 3. An illumination device selected from the group of a lamp, a luminaire, a projector device, and an optical wireless communication device, comprising a light generation system according to claim 1 or 2.

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