High-frequency wavelength-swept laser for mimicking continuous-wave emission with adjustable intensity profile

Abstract

The present invention relates to a light generating system 1000 having n first vertical cavity surface emitting lasers 110 and a control system 300, where n≧1, and each of the n first vertical cavity surface emitting lasers 110 has at least two centroid wavelengths λ 1 with a wavelength difference of at least 10 nm at a variation frequency of at least 50 Hz. nc,1 , λ nc,2 and the control system 300 is configured to control the n first vertical cavity surface emitting lasers 110 so that a system light 1001 including the first laser light 111 of at least one of the n first vertical cavity surface emitting lasers 110 is generated, and the control system 300 is configured to control a spectral power distribution of the system light 1001, and the system light 1001 is provided as a white light having a correlated color temperature in the range of 1800K to 8000K and a color rendering index of at least 70.

Description

[Technical field]

[0001] The present invention relates to a light-generating system. The present invention further relates to a light-generating device comprising such a light-generating system. [Background technology]

[0002] Devices including vertical cavity lasers are known in the art. For example, WO2004 / 107512 describes a white light laser integrated structure having a) a substrate and b) one or more individually addressable laser light pixels formed on the substrate to emit a white beam of laser light perpendicular to the substrate, each of the one or more individually addressable laser light pixels includes one or more organic light emitting diodes (OLEDs) and a plurality of organic vertical cavity lasers arranged to be optically pumped by the one or more OLEDs, the plurality of organic vertical cavity lasers emit light of different colors, and the one or more individually addressable laser light emitting pixels emit substantially white light when the light of the different colors is combined. The plurality of organic vertical cavity lasers emit light of two different colors. 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 2It 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 optical 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] It would be desirable to provide a light source that is tunable. However, laser-based light sources are generally not tunable. Furthermore, it would be desirable to provide a lighting device that has a spectral power distribution that is substantially conformal to the blackbody locus (at a desired correlated color temperature, CCT).

[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] In a first aspect, the present invention provides a light generation system ("system") comprising n first vertical cavity surface emitting lasers, a second light generating device, and a control system, where n > 1. The second light generating device is configured to generate second light generating device light. Each of the n first vertical cavity surface emitting lasers (in a first mode of operation of the light generating system) has at least two centroid wavelengths (λ nc,1 , λ nc,2 ), and the at least two center wavelengths may have a wavelength difference of at least 10 nm. Further, the first laser light may be configured to generate a first laser light having a wavelength variation frequency of at least 50 Hz, varying between at least two center wavelengths (λ nc,1 , λ nc,2 ) is varied between the first light generating device light (λ 1 ) and the second light generating device light (λ 2 ). The control system is configured to control the n first vertical cavity surface emitting lasers (in the first operation mode of the light generating system) such that a system light is generated comprising the first laser light of at least one of the n first vertical cavity surface emitting lasers and the second light generating device light. Furthermore, the control system is configured to control a spectral power distribution of the system light. In particular, the system light (in the first operation mode) is white light having a correlated color temperature in the range of 1800K to 8000K and a color rendering index of at least 70. Therefore, in particular, the present invention relates to a light generating system comprising n first vertical cavity surface emitting lasers and a control system, n≧1, wherein each of the n first vertical cavity surface emitting lasers is configured to vary (in the first operation mode of the light generating system) between at least two centroid wavelengths (λ 1 ) with a wavelength difference of at least 10 nm with a variation frequency of at least 50 Hz. nc,1, λ nc,2 ), and the control system is configured to control the n first vertical cavity surface emitting lasers such that (in the first operation mode of the light generation system) a system light is generated comprising the first laser light of at least one of the n first vertical cavity surface emitting lasers, in particular, the control system is configured to control a spectral power distribution of the system light, and (in the first operation mode) the system light is white light having a correlated color temperature in the range of 1800K to 8000K and a color rendering index of at least 70.

[0008] Such systems may be capable of providing light with a controllable spectral power distribution. Moreover, such systems may be capable of providing light with a controllable correlated color temperature and / or a controllable color rendering index. Moreover, such systems may be capable of providing a spectral power distribution that is partially or substantially conformal to the spectral power distribution (within the visible range) of a black body radiator.

[0009] As described above, the light generating system comprises n first vertical cavity surface emitting lasers.

[0010] Vertical-cavity surface-emitting lasers, or VCSELs, are known in the art and may be a type of semiconductor laser diode with a laser beam emitting vertically from the top surface, as opposed to edge-emitting semiconductor lasers (in-plane lasers), which emit from a surface formed by cutting individual chips from a wafer. As is known in the art, VCSELs may have tunable emission wavelengths. See, for example, Dupont et al., Applied Physics Letters 98(16):161105 - 161105-3, DOI:10.1063 / 1.3569591, Wendi Chang et al., Applied Physics Letters 105(7):073303, DOI:10.1063 / 1.4893758, Thor Ansbaek, IEEE Journal of Selected Topics in Quantum Electronics 19(4):1702306-1702306, DOI:10.1109 / JSTQE.2013.2257164, or CJ Chang-Hasnain, IEEE Journal of Selected Topics in Quantum Electronics (Volume: 6, Issue: 6, Nov.-Dec. 2000), DOI:10.1109 / 2944.902146, or Kogel et al., IEEE Sensors Journal, December 2007, volume 7, no. 11, pages 1483-1489, or Jayaraman et al., Electron Lett. 2012 Jul 5; 48(14): 867-869. doi: 10.1049 / el.2012.1552, all of which are incorporated herein by reference, describe tunable VCSELs. In particular, by varying the voltage, the spectral power distribution of said VCSELs can be varied. Thus, the term "VCSEL" may refer herein to such tunable VCSELs, in particular as known in the art. Such tunable VCSELs may be based on MEMS technology.Such a (tunable) VCSEL may be denoted as a "MEMS VCSEL". Thus, in an embodiment, the laser diode may comprise a vertical cavity surface emitting laser (VCSEL) with single mode emission and long coherence length. Wavelength sweeping may be performed using a microelectromechanical system (MEMS) to vary the length of the laser cavity, resulting in a stable and fast wavelength sweep.

[0011] Thus, various spectral power distributions may be generated with a VCSEL. In particular, the VCSEL is configured to generate (during operation of the VCSEL) a first laser light. The first laser light may therefore have a controllable spectral power distribution. By controlling the spectral power distribution of the first VCSEL, the spectral power distribution of the system light may be controlled. A control system may be applied to control the spectral power distribution. Thus, the light generation system may comprise a control system.

[0012] The first vertical cavity surface emitting laser may provide a first laser light with at least two different spectral power distributions at different times. In particular, the first vertical cavity surface emitting laser is therefore operated in a mode in which light with different spectral power distributions can be generated during different time periods. In other words, the spectral power distribution of the VCSEL may be controllable, so that the time-dependent centroid wavelength may change with time. This may be done relatively quickly, so that the eye may perceive a fixed spectral power distribution, and therefore, in effect, a (fixed) time-averaged centroid wavelength. Naturally, when changing the spectral power distribution from a first spectral power distribution to a second spectral power distribution in a time period that can be followed by the eye, the time-averaged centroid wavelength also changes from a first value to a second value.

[0013] In an embodiment of the operating mode of the system, the change between the at least two different spectral power distributions may be faster than the human eye can perceive. Thus, the change between the at least two different spectral power distributions may be within 0.025 seconds, such as within 0.02 seconds, or even within about 0.0167 seconds. With such a fast change, the eye does not see the change and perceives an essentially fixed spectral power distribution with a time-averaged centroid wavelength. Thus, the term "time-averaged centroid wavelength" as used herein may refer in particular to the centroid wavelength of the first laser light (of a VCSEL) averaged over a period longer than about 0.0167 seconds, more particularly longer than 0.02 seconds. Thus, the human eye may perceive a time-averaged centroid wavelength that may be essentially fixed over time (during the first operating mode), whereas the centroid wavelength may change within a period of 0.02 seconds, such as within a period of 0.0167 seconds.

[0014] The first vertical cavity surface emitting laser, in an embodiment, has (at least) two spectral power distributions, a first centroid wavelength λ nc,1 and the second centroid wavelength λ nc,2 In place of the term "sweep" and similar terms, the term "scan" or similar terms may also be used.

[0015] The spectral power distribution may be characterized by a centroid wavelength. The term "centroid wavelength", also denoted λc, is known in the art and refers to the wavelength value at which 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 halves the integral of the spectral power distribution as expressed by the formula λc=Σλ×I(λ) / (ΣI(λ), where the sum is over the wavelength range of interest, and 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, at operating conditions.

[0016] In particular, the first vertical cavity surface emitting laser therefore has at least two centroid wavelengths (λ nc,1 , λ nc,2 ) can be swept between two centroid wavelengths. Thus, in effect, in an operational mode, the first vertical cavity surface emitting laser (or more precisely its laser light) can be swept between two centroid wavelengths. When varying from the first centroid wavelength and the second centroid wavelength, intermediate centroid wavelengths may exist. Thus, the term "at least two centroid wavelengths (λ)" refers to a "tunable light generating device configured to generate a first laser light that can be swept between two centroid wavelengths (λ). nc,1 , λ nc,2 The term "at least two centroid wavelengths (λ)" is used. nc,1 , λ nc,2 In the embodiment, the first centroid wavelength and the second centroid wavelength (λ nc,1 , λ nc,2 ) may have a difference of at least 10 nm, such as at least 20 nm, at least 30 nm, or in further embodiments at least 40 nm (such as even at least 60 nm, or even at least 80 nm, in certain embodiments at least 100 nm). In certain embodiments, the at least two centroid wavelengths (λ nc,1 , λ nc,2 ) may be at least 50 nm. Furthermore, the change from the first to the second centroid wavelength may be at a frequency of at least 40 Hz, such as at least 50 Hz, or more particularly at least 60 Hz, such as at least 80 Hz (and in certain embodiments (even) at least 100 Hz). Thus, in an embodiment, the first vertical cavity surface emitting laser, in an operation mode of the light generation system, may change at least two centroid wavelengths (λ ) with a wavelength difference of at least 10 nm with a change frequency of at least 40 Hz. nc,1 , λ nc,2 ) in a wavelength-tunable light generating device configured to generate a first laser light having a frequency that varies between 0.1 and 0.25 Hz. In particular, the frequency of variation may be at least 60 Hz.

[0017] The (at least two) centroid wavelengths (λ nc,1 , λ nc,2 In an embodiment, the change between the (at least two) centroid wavelengths (λ 1 ) may be a jumping change, in which a first laser light having the first centroid wavelength is supplied in a first period, a first laser light having the second centroid wavelength is supplied in a second period, and the (at least two) centroid wavelengths (λ 2 ) are changed between the first period and the second period. nc,1 , λ nc,2 However, in an alternative embodiment, the (at least two) first laser lights having a different center wavelength (λ nc,1 , λ nc,2 In an embodiment, the change between the (at least two) centroid wavelengths (λ) may be a sweep change, in which a first laser light having the first centroid wavelength is supplied in a first period, a first laser light having the second centroid wavelength is supplied in a second period, and the (at least two) centroid wavelengths (λ) are changed between the first period and the second period. nc,1 , λ nc,2 ) is supplied. This means that the (at least two) center wavelengths (λ nc,1 , λ nc,2 ) over time. In particular, in an embodiment, this may result in a first laser light having a center wavelength that changes between the (at least two) center wavelengths (λ nc,1 , λ nc,2) resulting in a first laser light having a centroid wavelength that changes continuously between 0.025 s, 0.02 s, 0.0167 s, respectively. However, as mentioned above, the change between the at least two centroid wavelengths (here, particularly the change time) may be within a period of 0.025 s, more particularly within about 0.02 s, even more particularly within a period of 0.0167 s, so that the human eye may perceive a fixed (time-averaged) centroid wavelength. The periods, i.e. the first period and the second period, may each be independently selected from a range of at most 0.025 s, more particularly at most 0.02 s, even more particularly at most 0.0167 s. However, the change time and / or the period may also be much shorter, such as at least a factor of 10.

[0018] Thus, the first VCSEL may be operated continuously or pulsed.

[0019] The sweep change may essentially be a continuous change from one centroid wavelength to another and vice versa. The sweep change may also be a step change, in particular involving a number of intermediate centroid wavelengths. If a step change is applied, the steps may be up to 5 nm, such as up to 2 nm.

[0020] In the case where the system includes a single first vertical cavity surface emitting laser, this may be applied to the single first vertical cavity surface emitting laser. In the case where the system includes a plurality of first vertical cavity surface emitting lasers, this may be applied to each of the first vertical cavity surface emitting lasers.

[0021] In a particular embodiment, for each of the first vertical cavity surface emitting lasers, the change comprises changing the spectral power distribution of (at least) two, a first centroid wavelength λ 2 , a second centroid wavelength λ 3 , a third centroid wavelength λ 4 , a fourth centroid wavelength λ 5 , a fifth centroid wavelength λ 6 , a sixth centroid wavelength λ 7 , a sixth centroid wavelength λ 8 , a sixth centroid wavelength λ 9 , a seventh centroid wavelength λ 10 , a seventh centroid wavelength λ 11 , a seventh centroid wavelength λ 12 , a seventh centroid wavelength λ 13 , a seventh centroid wavelength λ 14 , a seventh centroid wavelength λ 15 , a seventh centroid wavelength λ 16 , a seventh centroid wavelength λ 17 , a seventh centroid wavelength λ 18 , a seventh centroid wavelength λ 19 , a seventh cent nc,1 and the second centroid wavelength λ nc,2It may be applied that, when n is 2 or more, at least two of the first VCSELs have the (respective) first centroid wavelength λ nc,1 and (each of) the second centroid wavelength λ nc,2 Note that the wavelength ranges may have only partially overlapping or non-overlapping wavelength ranges defined by

[0022] The system may also comprise one or more other vertical cavity surface emitting lasers (see also below). However, for the first vertical cavity surface emitting laser, in particular, each of the n first vertical cavity surface emitting lasers has at least two centroid wavelengths (λ 1 ) with a wavelength difference of at least 10 nm, with a variation frequency of at least 50 Hz (in a first operating mode of the light generating system). nc,1 , λ nc,2 It may also be applied that "each of the n first vertical cavity surface emitting lasers may be configured to generate a first laser light that varies between at least two centroid wavelengths (λ) (in a first operation mode of the light generation system). nc,1 , λ nc,2 The phrases "configured to generate a first laser light that varies between λ )" and similar phrases may, in embodiments, refer to a system having two or more first vertical cavity surface emitting lasers that have different, or even essentially always different, time-averaged spectral power distributions (in the first mode of operation). Thus, in embodiments where n is at least 2, at least one of the n first vertical cavity surface emitting lasers is configured (during the first mode of operation) to provide the first laser light averaged over time as an emission band, and the first laser light varies over time between the first centroid wavelength (λ 1c,1 ) and the second centroid wavelength (λ 1c,2 The (first) time-dependent centroid wavelength (λ 1ct), and (during the first mode of operation) at least another one of the n first vertical cavity surface emitting lasers is configured to provide the first laser light averaged over time as an emission band, and the first laser light varies over time with the first centroid wavelength (λ 2c,1 ) and the second centroid wavelength (λ 2c,2 ) and the (second) time-dependent centroid wavelength (λ 2ct ), in particular, the first time-dependent centroid wavelength (λ 1ct ) and the second time-dependent centroid wavelength (λ 2ct ) but more particularly at least (a) the first centroid wavelength λ 1c,1 and λ 2c,1 and / or (b) the second centroid wavelength λ 1c,2 and λ 2c,2 Similar considerations may apply when n=3 or more. In certain embodiments, there may be at least three different first VCSELs.

[0023] 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.

[0024] More particularly, as described below, when n is at least 2, the time-averaged spectral power distributions of the first laser lights of at least two of the at least two vertical cavity surface emitting lasers may only partially overlap or may not substantially overlap.

[0025] As mentioned above, the system may further comprise a control system, in particular configured to control the n first vertical cavity surface emitting lasers.

[0026] 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 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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).

[0031] 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.

[0032] In particular, in an embodiment, the control system may be configured to control the n first vertical cavity surface emitting lasers such that (in the first operation mode of the light generation system) a system light is generated comprising the first laser light of at least one of the n first vertical cavity surface emitting lasers. When n is at least 2, in particular, in an embodiment, the control system may be configured to control the n first vertical cavity surface emitting lasers such that (in the first operation mode of the light generation system) a system light is generated comprising the first laser light of at least two of the n first vertical cavity surface emitting lasers.

[0033] Furthermore, one or more of the n first vertical cavity surface emitting lasers together with the second light generating device, and optionally together with other light sources and / or optionally together with luminescent materials, may be controlled such that the system light (in the first mode of operation) comprises at least the first laser light of the one or more of the n first vertical cavity surface emitting lasers. Furthermore, in particular, the system light (in the first mode of operation) may be white light.

[0034] The second light-generating device may comprise one or more additional first vertical cavity surface-emitting lasers, such that n≧2, preferably n≧3, more preferably n≧4, even more preferably n≧5, such as n≧6 or n≧8 or n≧10. In another example, the second light-generating device may comprise one or more solid-state light sources, such as light-emitting diodes. In an embodiment, the second light-generating device may comprise one or more light-emitting diodes configured to generate blue light, and one or more luminescent materials configured to convert at least a portion of the blue light into luminescent material light, which may include one or more of yellow light, green light, orange light, and red light. The second light-generating device may be configured such that the second light-generating device light has an emission band with a full width at half maximum of at least 40 nm, preferably greater than 60 nm, more preferably greater than 80 nm, even more preferably greater than 90 nm.

[0035] The term white light and similar terms in this specification are known to those skilled in the art, and the white light has a correlated color temperature (CCT) between about 1800K and 20000K, such as at least about 2000K, particularly in the range of 2700-20000K, particularly in the range of about 1800-6800K for general illumination, such as at least about 2000K, such as 2700-6500K, particularly in the range of about 6500-20000K for backlight applications, and particularly within about 15 SDCM (standard deviation of color matching) from BBL (black body locus), particularly within about 10 SDCM from BBL, and even more particularly within about 5 SDCM from BBL.

[0036] In the present invention, it may be possible to select the spectral power distribution, or in an embodiment to control the spectral power distribution. Thus, in an embodiment, the CCT may be 1800K or more. In a further embodiment, the CCT may be 8000K or less. Furthermore, the color rendering index may be at least 60, such as at least 65, even more particularly at least about 70. Thus, in a particular embodiment, the control system may be configured to control the spectral power distribution of the system light, which (in the first mode of operation) may be white light having a correlated color temperature in the range of 1800K to 8000K and a color rendering index of at least 70. The phrase "the control system may be configured to control the spectral power distribution of the system light" and similar phrases may indicate in particular that the VCSEL, optionally together with other light sources and / or optionally together with luminescent materials, is controlled such that the system light may be white light.

[0037] The fact that the system may be configured to generate white light may not exclude that the system may also be configured to generate colored light. Similarly, the fact that the system may be configured to generate a system light having a correlated color temperature in the range of 1800K to 8000K and a color rendering index of at least 70 does not exclude that the system may also be configured to generate a system light that does not have a correlated color temperature in the range of 1800K to 8000K and / or does not have a color rendering index of at least 70. Thus, the system may be operated in a single mode of operation (specifically designated a first mode of operation) in embodiments, and may enable multiple modes of operation in other embodiments.

[0038] In particular, in an embodiment, one or more, more particularly each, of the n first vertical cavity surface emitting lasers has at least two centroid wavelengths (λ 1 ) with a wavelength difference of at least 10 nm, more particularly at least 20 nm (in a first operation mode of the light generating system). nc,1 , λ nc,2 ) in a wavelength range that varies between at least two centroid wavelengths (λ 1 ) in different portions of the visible wavelength range, where n is at least 2. At least two of the n first vertical cavity surface emitting lasers are configured to generate first laser light having at least two centroid wavelengths (λ 2 ) in different portions of the visible wavelength range that have a wavelength difference of at least 10 nm. nc,1 , λ nc,2 ) of the first vertical cavity surface emitting laser. Thus, the first vertical cavity surface emitting laser may be configured to generate a first laser light that changes between at least two centroid wavelengths (λ nc,1 , λ nc,2 ) may only partially overlap or may not overlap at all.

[0039] As described above, in an embodiment, (in the first mode of operation) at least one of the one or more first vertical cavity surface emitting lasers has a first centroid wavelength (λ nc,1 ) and the second centroid wavelength (λ nc,2) in a particular embodiment. Thus, (during the first mode of operation) the at least one of the n first vertical cavity surface emitting lasers may be configured to provide the first laser light averaged over time as an emission band, the first laser light varying over time between the first centroid wavelength (λ nc,1 ) and the second centroid wavelength (λ nc,2 ) and the time-dependent centroid wavelength (λ nct In certain embodiments where n is at least 2, at least two of the n first vertical cavity surface emitting lasers may be configured to provide the first laser light averaged over time as an emission band, the first laser light varying over time with the first centroid wavelength (λ nc,1 ) and the second centroid wavelength (λ nc,2 ) and the time-dependent centroid wavelength (λ nct ), and in particular, the time-dependent centroid wavelength (λ ) of the at least two of the n first vertical cavity surface emitting lasers nct ) are different.

[0040] The band shape of the emission band may be controlled by the control system. Thus, in embodiments, the band shape may be substantially conformal to a portion of the spectral power distribution of a blackbody radiator (emission) at a particular temperature. For example, in embodiments, the at least one of the one or more first vertical cavity surface emitting lasers has a first centroid wavelength (λ nc,1 ) and the second centroid wavelength (λ nc,2 ), and the intensity may be selected such that the band has a band shape whose peak height may be essentially conformal to the spectral power distribution of blackbody radiation (at a particular temperature). nc,1 ) and the second centroid wavelength (λ nc,2 ) may be conformal to the spectral power distribution of a black body radiator (emission) at a particular temperature. The particular CCT may be selected from the range of 1800 to 8000 K and may be controllable in certain embodiments.

[0041] Here, “conformal” means that the first centroid wavelength (λ nc,1 ) and the second barycenter wavelength (λ nc,2 ) the average distance to the BBL, averaged over wavelengths, is within 10 SDCM from the BBL. In more particular embodiments, it is within about 5 SDCM from the BBL, such as within about 3 SDCM from the BBL.

[0042] In a particular embodiment, the spectral power distribution of the system light in the visible range may be divided into k wavelength ranges (of equal width in nanometers), where k may be at least 10. For example, the wavelength range of 380 to 780 nm may be divided into 40 ranges of 10 nm each, or 80 ranges of 5 nm each. The value of k is essentially unlimited. For example, k may be 400 or more, such as 4000 or more. In particular, it may apply for at least 10%, more particularly at least 20%, even more particularly at least 40%, even more particularly at least 30% of these k wavelength ranges that the intensity in these parts, over the entire wavelength range (of such wavelength ranges), is always within 10 SDCM, such as within 5 SDCM of the BBL for a particular CCT. For even more particularly at least 50% of these k wavelength ranges, such as at least 70%, such as at least 60%, and even more particularly at least 50%, it may apply that the intensity in these portions is always within 10 SDCM, such as within 5 SDCM of the BBL for a particular CCT, across the entire wavelength range. In this manner, a significant portion of the spectral power distribution of the system light in the visible wavelength range may be conformal to the spectral power distribution of the emission of a blackbody radiator at a particular temperature.

[0043] Therefore, in a particular embodiment, each of the n first vertical cavity surface emitting lasers has at least two centroid wavelengths (λ 1 ) with a wavelength difference of at least 20 nm (in a first operating mode of the light generating system). nc,1 , λnc,2 ), and at least one of the n first vertical cavity surface emitting lasers is configured to generate a first laser light having a first centroid wavelength (λ nc,1 ), a first laser light having a first time period and a second centroid wavelength (λ nc,2 and a second period of first laser light having a first centroid wavelength (λ 1 ), each at a time period frequency of at least 50 Hz, and (during the first mode of operation) the at least one of the n first vertical cavity surface emitting lasers is configured to provide the first laser light averaged over time as an emission band, and the first laser light varies over time with the first centroid wavelength (λ 1 ). nc,1 ) and the second centroid wavelength (λ nc,2 ) and the time-dependent centroid wavelength (λ nct ) wherein the time-averaged spectral power distribution of the first laser light is conformal to the spectral power distribution of the emission of a black body radiator at a particular temperature (particular CCT) in the range of 1800 to 8000 K.

[0044] In an embodiment, n is at least 2, such as 2 or 3 or 4. In particular, the (at least) two first vertical cavity surface emitting lasers may generate time-averaged emission bands that only partially overlap, such as at most 50%, more particularly at most 25%, even more particularly at most 10%, even more particularly at most 5%. The phrase "different wavelength ranges with less than 50% overlap" and similar phrases may indicate that each of the two emission bands overlaps with the other of the two emission bands by less than 50%. Thus, in a particular embodiment, the system (in the first mode of operation) may generate time-averaged emission bands that only partially overlap, such as at most 50%, more particularly at most 25%, even more particularly at most 10%, even more particularly at most 5%. nc,1 , λ nc,2 ) may include at least two first vertical cavity surface emitting lasers configured to generate a first laser light that varies between

[0045] In particular embodiments, 1≦n≦16, more particularly, 2≦n≦16, such as 2≦n≦12, especially such as 3≦n≦12.

[0046] In particular, the time-averaged centroid wavelengths may be selected from different wavelength ranges. In such embodiments, the overlap may be very small or essentially zero. Thus, in a particular embodiment, the system (in the first operation mode of the light-generating system) has different time-averaged centroid wavelengths (λ ) selected from (different) wavelength ranges from the group of 440 to 495 nm, 495 to 570 nm, 570 to 590 nm, 590 to 620 nm and 620 to 780 nm. nac In yet another specific embodiment, the laser may further include at least two (i.e., n≧2) first vertical cavity surface emitting lasers configured to generate first laser light having a time-averaged centroid wavelength (λ nac For example, a first vertical cavity surface emitting laser may have a time-averaged centroid wavelength (λ ) selected from a wavelength range of 440 to 495 nm (in the first operating mode of the light generating system). nac ), and another first vertical cavity surface emitting laser may be configured to generate a first laser light having a time-averaged centroid wavelength (λ ) selected from a wavelength range of 620 to 780 nm (in the first mode of operation of the light generation system). nac Such an embodiment may further comprise a first vertical cavity surface emitting laser configured to generate a first laser light having a time-averaged centroid wavelength (λ ) selected from a wavelength range in the group of 495 to 570 nm and 570 to 590 nm (in the first mode of operation of the light generation system). nac It is not excluded that the laser beam may be configured to generate a first laser beam having a first wavelength of 1000 nm.

[0047] Therefore, in a particular embodiment, the system (in the first operation mode of the light-generating system) is adapted to emit light at different time-averaged centroid wavelengths (λ 2 ) selected from (different) wavelength ranges of the group: 440 to 495 nm, 495 to 570 nm, 570 to 590 nm, 590 to 620 nm and 620 to 780 nm. nac ), and may include at least three (i.e., n≧3) first vertical cavity surface emitting lasers configured to generate first laser light having at least three time-averaged centroid wavelengths (λ nac ) differ from each other by at least 40 nm. For example, nac ) may be selected from the ranges: (a) 460 nm + / - 20 nm, (b) 550 nm + / - 25 nm, and (c) 620 nm + / - 30 nm.

[0048] “Time-averaged centroid wavelength (λ nac The phrase "at least two centroid wavelengths" and similar phrases may refer to the observed centroid wavelength when measured over a period of at least 1 / 50 Hz, i.e., at least 0.02 seconds, such as averaged over a period selected from the range of 0.2 to 2 seconds. Within such a period, a particular VCSEL may change between the at least two centroid wavelengths multiple times, resulting in a time-averaged centroid wavelength (λ) that is perceptually perceptible to the human eye. nac ) may result.

[0049] In this manner, across a wavelength range in the visible range, the first VCSEL may generate a spectral power distribution at several wavelength ranges in a spectrum that together (in the first mode of operation) may provide the system light, which may thus be white light in certain embodiments. In this manner, in certain embodiments, at least a portion of the spectral power distribution may be substantially conformal to the spectral power distribution of a black body radiator (emission) at a particular temperature.

[0050] In a particular embodiment, the n first vertical cavity surface emitting lasers are configured to generate (in the first mode of operation) system light having a radiant flux at at least four different wavelengths in a wavelength range of 380-780 nm, the minimum and maximum wavelengths at which the n first vertical cavity surface emitting lasers provide intensity are over a wavelength range of at least 110 nm, and at least 50% of the radiant flux of the first laser light, averaged over time, is in the at least four different wavelength ranges in the range of 380-780 nm. In particular, this can be obtained with four different VCSELs, but this may also be achieved with more or fewer VCSELs depending on the wavelength range controllability of the VCSELs. For example, these wavelength ranges may be selected from the group of 440-495 nm, 495-570 nm, 570-590 nm, 590-620 nm, and 620-780 nm. In particular, if there are five or more different wavelength ranges in which intensity is provided, intensity may be provided in each of these four wavelength ranges. In this manner, a substantially continuous spectral power distribution of the system light can be provided.

[0051] More particularly, in an embodiment, at least one of the n first vertical cavity surface emitting lasers (in the first mode of operation) may be configured to generate a first laser light, where at least 50% of the radiant flux of the first laser light, averaged over time, is in at least six different non-overlapping wavelength ranges of at least 10 nm width in the range of 380 to 780 nm. In particular, this may be obtained with six different VCSELs, but this may also be achieved with more or fewer VCSELs depending on the wavelength range controllability of the VCSELs. For example, these wavelength ranges may be selected from the group of 440 to 495 nm, 495 to 570 nm, 570 to 590 nm, 590 to 620 nm, and 620 to 780 nm. In particular, an intensity may be provided in each of these four wavelength ranges of 440 to 495 nm, 495 to 570 nm, 570 to 590 nm, 590 to 620 nm, and 620 to 780 nm. In this manner, a substantially continuous spectral power distribution can be provided.

[0052] Further, more particularly, in an embodiment, at least one of the n first vertical cavity surface emitting lasers (in the first operating mode) may be configured to generate a first laser light, where at least 60% of the radiant flux of the first laser light, averaged over time, is in at least eight different non-overlapping wavelength ranges of at least 10 nm width in the range of 380 to 780 nm. In particular, this may be obtained with eight different VCSELs, but this may also be achieved with more or fewer VCSELs depending on the wavelength range controllability of the VCSELs. For example, these wavelength ranges may be selected from the group of 440 to 495 nm, 495 to 570 nm, 570 to 590 nm, 590 to 620 nm, and 620 to 780 nm. In particular, an intensity may be provided in each of these four wavelength ranges of 440 to 495 nm, 495 to 570 nm, 570 to 590 nm, 590 to 620 nm, and 620 to 780 nm. In this manner, a substantially continuous spectral power distribution can be provided. More particularly, at least one of the n first vertical cavity surface emitting lasers (in the first mode of operation) may be configured to generate a first laser light, where at least 70%, such as at least 80%, of the radiant flux of the first laser light, averaged over time, is within at least eight different non-overlapping wavelength ranges at least 10 nm wide within a range of 380 to 780 nm.

[0053] Further, in a more particular embodiment, at least one of the n first vertical cavity surface emitting lasers (in the first mode of operation) is configured to generate a first laser light, where at least 80% of the radiant flux of the first laser light, averaged over time, is in at least eleven different non-overlapping wavelength ranges of at least 10 nm width within the range of 380-780 nm. In particular, this can be obtained with eight different VCSELs, but this may be achieved with more or fewer VCSELs depending on the wavelength range controllability of the VCSELs. For example, these wavelength ranges may be selected from the group of 440-495 nm, 495-570 nm, 570-590 nm, 590-620 nm, and 620-780 nm. In particular, intensity may be provided in each of these four wavelength ranges of 440-495 nm, 495-570 nm, 570-590 nm, 590-620 nm, and 620-780 nm. In this manner, a substantially continuous spectral power distribution can be provided. More particularly, at least one of the n first vertical cavity surface emitting lasers (in the first mode of operation) is configured to generate a first laser light, where at least 90% of the radiant flux of the first laser light, averaged over time, is in at least eleven distinct non-overlapping wavelength ranges at least 10 nm wide within a range of 380 to 780 nm.

[0054] In embodiments, the system may provide the system light with only one or more first VCSELs, such as at least two different first VCSELs, more particularly at least three different first VCSELs, and in more particular embodiments at least four different first VCSELs. However, in other embodiments, the system may also include a luminescent material, which may be configured to convert at least a portion of the light of one of the first VCSELs and / or another light source.

[0055] Therefore, in an embodiment, the system may further comprise a luminescent material configured to convert at least a portion of the light of the second light-generating device, and (in the first operating mode) the system light comprises luminescent material light, which may in particular embodiments have an emission band with a full width at half maximum of at least 30 nm, more particularly at least 40 nm, and in more particular embodiments at least 60 nm.

[0056] Alternatively or additionally, the system may further comprise a luminescent material configured to convert at least a portion of the light of at least one of the n first vertical cavity surface emitting lasers, and (in the first mode of operation) the system light may comprise luminescent material light, the luminescent material light having an emission band with a full width at half maximum of at least 30 nm, more particularly at least 40 nm, in more particular embodiments at least 60 nm. Thus, the laser light of one or more first VCSELs of the at least one first VCSEL may be used to convert (at least in part) into luminescent material light.

[0057] 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.

[0058] 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

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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 garnet includes A at least yttrium or lutetium and B 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 includes aluminum (Al), but B may also partially include gallium (Ga) and / or scandium (Sc) and / or indium (In), in particular up to about 20% of Al, more in particular up to about 10% of Al (i.e., B ions essentially consist 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 partially 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.

[0063] In an embodiment, the luminescence material is (thus) A3B5O 12 and, in certain embodiments, up to 10% of the B-O may be replaced by Si-N.

[0064] In certain embodiments, 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' includes one or more elements selected from the group consisting of lanthanides, and B' includes 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.

[0065] In certain embodiments, up to 10% of the B-O may 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 certain embodiments, B-O may refer to Al-O. As described above, in certain embodiments, x3 may 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 certain embodiments, A may be selected from the group consisting of Lu and Gd. Alternatively, or in addition, B may include Ga. Thus, in an embodiment, the luminescence material is (Y x1-x2-x3 (Lu,Gd) x2 Ce x3 )3(Al y1-y2 Ga y2 )5O12 It includes 12 , 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 still other certain embodiments, the luminescence material is (Y x1-x3 Ce x3 )3Al5O 12 It includes, x1 + x3 = 1, 0 < x3 ≤ 0.2, such as 0.001 to 0.1, etc.

[0066] In certain embodiments, the light generating device may only include a luminescence material selected from the garnet type containing cerium. In still other certain 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 etc. Thus, in certain embodiments, the light generating device has a luminescence material, and at least 85 wt%, even more particularly at least about 90 wt%, for example even more particularly at least about 95 wt% of the luminescence material is (Y x1-x2-x3 A' x2 Ce x3 )3(Al y1-y2 B' y2 )5O 12 Here, A' includes one or more elements selected from the group consisting of lanthanides, B' includes 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. Note that in embodiments, x2 = 0. Instead, or in addition, in embodiments, y2 = 0.

[0067] In certain embodiments, A may, inter alia, include at least Y, and B may, inter alia, include at least Al.

[0068] Thus, in certain embodiments, the luminescent material is ABO 12 :Ce type luminescent materials, where A comprises one or more of Y, La, Gd, Tb and Lu, and B comprises one or more of Al, Ga, In and Sc.

[0069] Alternatively, or in addition, the luminescent material may be A3Si6N 11 :Ce 3+ The present invention may include luminescent materials of the type A, where A includes one or more of Y, La, Gd, Tb, and Lu, such as one or more of La and Y in embodiments.

[0070] In an embodiment, the luminescent material may alternatively or additionally be 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 fact that a portion of the metal ions are 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 0.5 In 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.

[0071] 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.

[0072] 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).

[0073] 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 Ba1.5 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).

[0074] 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).

[0075] The Eu in the above luminescent materials is substantially or exclusively in a divalent state, as known to those skilled in the art.

[0076] 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.

[0077] The term "luminescent material" as used herein relates specifically to inorganic luminescent materials.

[0078] Instead of the term "luminescent material", the term "phosphor" is sometimes applied, these terms being known to those skilled in the art.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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).

[0084] 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.

[0085] The phrase "one or more first VCSELs of the at least one first VCSEL" and similar phrases may also be indicated as "k1 first VCSELs of the n first VCSELs," where n≧1 and 1≦k1≦n.

[0086] Alternatively or in addition, the system may comprise another light source, the light of which may itself be included in the system light. Whereas the first light source may provide a first laser light with a time variable centroid wavelength, in embodiments such another light source may be configured to generate source light with an essentially fixed centroid wavelength, and may for example be a laser diode. In embodiments, the system may further comprise a third light generating device configured to generate a third device light, which may comprise a laser, and the third device light has a third device light centroid wavelength (λ ) that is at a fixed position (during the first mode of operation). c3 ), and the n first vertical cavity surface emitting lasers may have a time-averaged centroid wavelength (λ ) (in the first mode of operation of the light generating system). nac ), and in particular, the third device optical centroid wavelength (λ c3 ) is the time-averaged centroid wavelength (λ nac ) may differ from at least one of the following: u'=0.03 and / or v'=0.03; more particularly, u'=0.02 and / or v'=0.02. The term "fixed position" may mean that the spectral position of the third device light may be essentially fixed, in particular at frequencies higher than 50 Hz, for example such that the difference is at most 0.03 for u' and / or at most 0.03 for v', and even more particularly, at most 0.02 for u' and / or at most 0.02 for v'. In yet more particular embodiments, the respective color points of the first type of light and the second type of light may differ by at most 0.01 for u' and / or at most 0.01 for v', where u' and v' are the color coordinates of light in the CIE 1976 UCS (Uniform Chromaticity) diagram.

[0087] In certain embodiments, the control system may be configured to control the correlated color temperature of the system light (in the first operational mode) to a value selected from the range of 1800 to 6500 K, the correlated color temperature of the system light being controllable over a CCT control range of at least about 300 K, such as at least 500 K, at least within the range of 1800 to 6500 K.

[0088] Thus, in an embodiment (in the first mode of operation), the CCT of the system light may be selected from a first correlated color temperature (CCT1) and a second correlated color temperature (CCT2), where |CCT2-CCT1|≧300 K. For example, 300 K≦|CCT2-CCT1|≦5000 K, such as 800 K≦|CCT2-CCT1|≦4700 K, more particularly 1000 K≦|CCT2-CCT1|≦4500 K. In an embodiment (in the first mode of operation), the CCT of the system light may be selected from a first correlated color temperature (CCT1) and a second correlated color temperature (CCT2), where 1000 K≦|CCT2-CCT1|≦2500 K.

[0089] Conformance to the BBL can be achieved by controlling the intensity at various wavelengths such that the spectral power distribution is conformal to the BBL, which can be done by controlling the duty cycle and / or at one or more of the supplied powers.

[0090] In certain embodiments, the control system may be configured to control the color rendering index of the system light (in the first operating mode) to a value of at least 70, more particularly at least 80, and even more particularly at least 90, and controlling the spectral power distribution of the system light (in the first operating mode) includes individually controlling the duty cycle of the first pulse and the duty cycle of the second period.

[0091] In an embodiment, R9 may be at least 0, such as 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 yet further embodiments, n≧3, and the control system is configured to control the R9 value of the system light (in the first mode of operation) to a value of at least 40, the R9 value being controllable over an R9 control range of at least 30, the R9 control range at least partially overlapping with a range of at least 40, and the color rendering index of the system light (in the first mode of operation) being at least 80.

[0092] 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.

[0093] 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 an embodiment the lighting device may have a housing configured to accommodate or a carrier configured to support one or more of the control system and the first VCSEL.

[0094] Therefore, the present invention also provides, in one aspect, an illumination device selected from the group of a lamp, a luminaire, a projector device, a disinfection device, a photochemical reactor, and an optical wireless communication device, the illumination device having a light generation system as defined herein.

[0095] The terms "visible," "visible light," or "visible emission," and similar terms, refer to light having one or more wavelengths within the range of about 380 to 780 nm. As used herein, UV may refer specifically to wavelengths selected from the range of 190 to 380 nm, such as 200 to 380 nm.

[0096] As used herein, 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" can 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.

[0097] 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. [Brief description of the drawings]

[0098] 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 1a] Several embodiments and aspects are illustrated diagrammatically. [Figure 1b] Several embodiments and aspects are illustrated diagrammatically. [Figure 2a] 1 illustrates a schematic diagram of some embodiments, showing a spectral power distribution with a CCT of 2700K, a CRI of 93, and an R9 of 40. [Figure 2b] 1 illustrates a schematic diagram of some embodiments, showing a spectral power distribution with a CCT of 2700K, a CRI of 93, and an R9 of 40. [Figure 2c] 1 illustrates a schematic diagram of some embodiments, showing a spectral power distribution with a CCT of 2700K, a CRI of 93, and an R9 of 40. [Figure 3a] 1 illustrates diagrammatically embodiments and variants; [Figure 3b] 1 shows a schematic diagram of an embodiment and a variant thereof, with a CCT of 2840K, a CRI of 94 and an R9 of 61. [Figure 3c] 1 shows a schematic diagram of an embodiment and a variant thereof, with a CCT of 2840K, a CRI of 94 and an R9 of 61. [Figure 4] Several embodiments are illustrated diagrammatically.

[0099] The schematic drawings are not necessarily to scale. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0100] 1a-1b, several embodiments and aspects of and relating to a light-generating system 1000 having n first vertical cavity surface-emitting lasers 110 and a control system 300 are illustrated. In particular, n≧1. Here, as an example, n=3.

[0101] Each of the n first vertical cavity surface emitting lasers 110 may be configured to generate a first laser light 111 (in a first operation mode of the light generation system 1000). The n first vertical cavity surface emitting lasers 110 are denoted by reference characters 110a, 110b, and 110c. The laser light 111 of each of the n first vertical cavity surface emitting lasers 110 is denoted by reference characters 111a, 111b, and 111c, respectively. The laser light 111a, 111b, and 111c of each of the n first vertical cavity surface emitting lasers 110 have at least two centroid wavelengths (λ 1 ) with a wavelength difference of at least 10 nm (during the first operation mode). nc,1 , λ nc,2 ) (see also FIG. 1b). The variation may be at a variation frequency of at least 50 Hz.

[0102] The dashed rectangle included in the first VCSEL 110 may, by way of example, refer to a MEMS that may be used to control the time-dependent spectral power distribution of the (respective) first laser light.

[0103] The control system 300 may be configured to control the n first vertical cavity surface emitting lasers 110 so that (in a first operating mode of the light generation system 1000) system light 1001 including a first laser light 111 of at least one of the n first vertical cavity surface emitting lasers 110 may be generated (see also FIG. 2).

[0104] The reference number 410 may refer to an optical element. The term "optical system" may particularly refer 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 a mirror, a reflector, a collimator, a lens, a prism, a diffuser, a phase plate, a polarizer, a diffractive element, a diffraction grating, a dichroic, an array 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 a beam expander optical system and a zoom lens optical system. For examples of optical systems, see further above. The optical element 410 may particularly include a beam shaping element, such as a concentrator. For example, the optical element 410 may include a compound parabolic concentrator (CPC). Alternatively or in addition, the optical element 410 may include a lens.

[0105] The control system 300 may be configured to control the spectral power distribution of the system light 1001 .

[0106] For example, and referring also to FIGS. 2 and 3, the system light 1001 (in a first mode of operation) may be a white light having a correlated color temperature in the range of 1800K to 8000K and a color rendering index of at least 70 in an embodiment.

[0107] In an embodiment, each of the n first vertical cavity surface emitting lasers 110 has at least two centroid wavelengths (λ 1 ) with a wavelength difference of at least 10 nm, such as at least 20 nm (in a first operating mode of the light generation system 1000). nc,1 , λ nc,2 ) may be configured to generate a first laser light 111 that varies between

[0108] At least one of the n first vertical cavity surface emitting lasers 110 has a first centroid wavelength (λ nc,1), and the first laser light 111 in the first period has a second centroid wavelength (λ nc,2 ) and a second period of the first laser light 111 having a periodic frequency of at least 50 Hz, respectively.

[0109] At least one of the n first vertical cavity surface emitting lasers 110 may be configured to provide (during a first mode of operation) a time-averaged first laser light 111 as an emission band.

[0110] The first laser light 111 becomes smaller with time as the first centroid wavelength (λ nc,1 ) and the second centroid wavelength (λ nc,2 ) and the time-dependent centroid wavelength (λ nct ).

[0111] With reference to Fig. 1b, three schematic illustrated embodiments may show the spectral power distribution of a VCSEL at different times. Thus, a spectral power distribution averaged over time may be provided as shown, by way of example, in schematic views I to III of Fig. 1b, with the respective time-averaged centroid wavelengths λ nac results.

[0112] The spectral power distribution of the first laser light 111 averaged over time may be conformal to the spectral power distribution of the emission of a blackbody radiator at a particular correlated color temperature in the range of 1800 to 8000 K, or at least a portion thereof (see also Figures 2a to 2c).

[0113] 2a-2c, in an embodiment, the light-generating system (in a first mode of operation of the light-generating system 1000) provides at least two centroid wavelengths (λ 1 ) in at least two different wavelength ranges, where the wavelength ranges overlap by less than 50%. nc,1 , λ nc,2In particular, the system 1000 may comprise at least two first vertical cavity surface emitting lasers 110 configured to generate a first laser light 111 varying between different time-averaged centroid wavelengths (λ ) selected from (different) wavelength ranges of the group of 440 to 495 nm, 495 to 570 nm, 570 to 590 nm, 590 to 620 nm, and 620 to 780 nm (in a first mode of operation of the light generating system 1000). nac ) may include at least two first vertical cavity surface emitting lasers 110 configured to generate a first laser light 111 having at least two time-averaged centroid wavelengths (λ nac More particularly, in an embodiment, the system 1000 (in a first mode of operation of the light-generating system 1000) provides different time-averaged centroid wavelengths (λ ) selected from (different) wavelength ranges of the group: 440 to 495 nm, 495 to 570 nm, 570 to 590 nm, 590 to 620 nm, and 620 to 780 nm. nac ) may include at least three first vertical cavity surface emitting lasers 110 configured to generate a first laser light 111 having at least three time-averaged centroid wavelengths (λ nac ) may differ from each other by at least 40 nm.

[0114] FIG. 2a illustrates that the first vertical cavity surface emitting laser 110 has at least two centroid wavelengths (λ ) with no intermediate centroid wavelength. nc,1 , λ nc,2 2b shows an embodiment in which a first vertical cavity surface emitting laser 110 can be switched between two (extreme) centroid wavelengths (λ nc,1 , λ nc,2 2c shows an embodiment in which the emission band is swept between 100 Hz and 100 Hz. This can result in a substantially continuous emission band, as shown in FIG. 2c.

[0115] Figure 2c shows the centroid wavelength (λ nc,1 , λ nc,22a-b show an embodiment showing a sweep between 1000 nm and 1000 nm, where the sweep may be essentially a continuous change in emission wavelength and therefore essentially a continuous change in time-dependent centroid wavelength, resulting in an emission band. This emission band may essentially be for a portion of the blackbody locus at a particular correlated color temperature. In Figs. 2a-b, the spectral power distribution of a blackbody radiator (emission) at a particular temperature is shown by the dashed line.

[0116] With reference to FIG. 2b (and also with reference to FIG. 2c), the spectral power distribution of the system light in the visible range may be divided into k wavelength ranges (of equal width in nanometers), where k may be at least 10. For example, the wavelength range of 380 to 780 nm may be divided into 40 ranges of 10 nm each, or 80 ranges of 5 nm each. The value of k is essentially unlimited. In particular, it may apply that for at least 10%, more particularly at least 20%, even more particularly at least 40%, even more particularly at least 30% of these k wavelength ranges, the intensity in these parts is always within 10 SDCM, such as within 5 SDCM of the BBL for a particular CCT, over the entire wavelength range. Here, in FIG. 2b to 2c, by way of example, (at least) four ranges of at least 10 nm each are essentially conformal within 10 SDCM of the BBL for a particular CCT.

[0117] 2a-2c and 3a-3c, the n first vertical cavity surface emitting lasers 110 may be configured, in an embodiment, to generate system light 1001 having radiant flux at at least four different wavelengths in a wavelength range of 380-780 nm (in a first mode of operation). In particular, the minimum and maximum wavelengths at which the n first vertical cavity surface emitting lasers 110 provide intensity span a wavelength range of at least 110 nm. The extreme centroid wavelengths (λ nc,1 , λ nc,2 ) is denoted by the reference symbol Δλ nc As shown in the figure.

[0118] In FIGS. 2a-2b, n is at least two, and during a first mode of operation, at least one of the n first vertical cavity surface emitting lasers 110 is configured to provide a time-averaged first laser light 111 as an emission band, the first laser light 111 varying over time at a first centroid wavelength λ 1c,1 and the second centroid wavelength λ 1c,2 The first time-dependent centroid wavelength λ that varies between 1ct and during a first mode of operation, at least another one of the n first vertical cavity surface emitting lasers 110 is configured to provide a time-averaged first laser light 111 as an emission band, the first laser light 111 varying over time at a first centroid wavelength λ 2c,1 and the second centroid wavelength λ 2c,2 The second time-dependent centroid wavelength λ changes between 2ct In particular, the first time-dependent centroid wavelength λ 1ct and the second time-dependent centroid wavelength λ 2ct More particularly, at least (a) the first centroid wavelength λ 1c,1 and λ 2c,1 and / or (b) the second centroid wavelength λ 1c,2 and λ 2c,2 are also different.

[0119] In FIG. 2a to FIG. 2b, for n=4 first VCSELs, each first centroid wavelength λ nc,1 and the second centroid wavelength λ nc,2 However, reference symbol λ 1c,1 and λ 1c,2 , λ 2c,1 and λ 2c,2 , λ 3c,1 and λ 3c,2 , and λ 4c,1 and λ 4c,2 As shown in the figure.

[0120] In an embodiment, at least 50% of the radiant flux of the first laser light, averaged over time, may be provided in at least four different wavelength ranges within the range of 380 to 780 nm.

[0121] 2a-2c, in an embodiment, at least one of the n first vertical cavity surface emitting lasers 110 (in a first operation mode), more particularly each of the n first vertical cavity surface emitting lasers 110, may be configured to generate a first laser light 111. At least 50% of the radiant flux of the first laser light averaged over time may be in at least six different non-overlapping wavelength ranges of at least 10 nm width within the range of 380-780 nm. Note that although the laser light 111 of only four first vertical cavity surface emitting lasers 110 is illustrated in FIG. 2a-2c, n may be greater than 4 in an embodiment (or less than 4 in other embodiments), as would be clear to one skilled in the art.

[0122] In a particular embodiment, at least one of the n first vertical cavity surface emitting lasers 110 (in a first operating mode) may be configured to generate the first laser light 111. In particular, all of the n first vertical cavity surface emitting lasers 110 may be configured together to generate the first laser light 111. At least 60% of the radiant flux of the first laser light averaged over time may be in at least eight different non-overlapping wavelength ranges of at least 10 nm width within the range of 380 to 780 nm. Even more particularly, in an embodiment, at least one of the n first vertical cavity surface emitting lasers 110 (in a first operating mode), more particularly, all of the n first vertical cavity surface emitting lasers 110 may be configured together to generate the first laser light 111. In particular, at least 80% of the radiant flux of the first laser light averaged over time may be in at least eleven different non-overlapping wavelength ranges of at least 10 nm width within the range of 380 to 780 nm.

[0123] Referring to embodiment I of Fig. 3a, the light-generating system 1000 may further comprise a luminescent material 200 configured to convert at least a portion of the light of the second light-generating device 120. The system light 1001 may comprise (in a first mode of operation) luminescent material light 201. In a particular embodiment, the luminescent material light 201 may have an emission band with a full width at half maximum of at least 40 nm. A possible spectral power distribution is illustrated diagrammatically in Fig. 3b.

[0124] Referring to embodiment II of Fig. 3a, the light-generating system 1000 may further comprise a luminescent material 200 configured to convert at least a portion of the light of at least one of the n first vertical cavity surface-emitting lasers 110. The system light 1001 may comprise (in a first operating mode) a luminescent material light 201. In particular, the luminescent material light 201 may have an emission band with a full width at half maximum of at least 40 nm. A possible spectral power distribution is illustrated diagrammatically in Fig. 3b.

[0125] In embodiments such as embodiments I and II of FIG. 3a, the luminescent material 200 is ABO 12 :Ce 3+ A may comprise one or more of the following luminescent materials: A may comprise one or more of Y, La, Gd, Tb, and Lu; B may comprise one or more of Al, Ga, In, and Sc. Alternatively, or in addition, the luminescent material may comprise one or more other luminescent materials.

[0126] The luminescent material may be configured downstream of the first VCSEL or the optional second light source 120. In embodiments, different luminescent materials may be configured downstream of different VCSELs and / or the optional second light source 120. In certain embodiments, no luminescent material is configured downstream of at least one VCSEL, and more particularly downstream between at least two different VCSELs (i.e., the primary laser light of such a VCSEL may ultimately become the system light (in an operational mode)).

[0127] The terms "upstream" and "downstream" relate to the positioning of an item or feature relative to the propagation of light from a light generating means (here, in particular the light source), such that relative to a first position in the light beam from the light generating means, a second position in the light beam closer to the light generating means is "upstream" and a third position in the light beam further away from the light generating means is "downstream".

[0128] Referring to embodiment III of FIG. 3a, the light-generating system 1000 may further comprise a third light-generating device 130 configured to generate a third device light 131. The third light-generating device 130 may comprise a laser. The third device light 131 has a third device light centroid wavelength (λ ) that may be at a fixed position (during the first mode of operation). c3 In particular, the n first vertical cavity surface emitting lasers 110 have a time-averaged centroid wavelength (λ nac ) may be configured to generate a first laser light 111 having a third device optical centroid wavelength (λ c3 ) is the time-averaged centroid wavelength (λ nac ), and more particularly, may be different from at least one of the time-averaged centroid wavelengths (λ ) of the first laser light 111 of all the n first vertical cavity surface emitting lasers 110. nac ) may be different from all of the above. Possible spectral power distributions are illustrated diagrammatically in FIG. 3c.

[0129] In certain embodiments, the control system 300 may be configured to control the correlated color temperature of the system light 1001 (in the first mode of operation) to a value selected from the range of 1800 to 6500 K. In particular, in embodiments, the correlated color temperature of the system light 1001 may be controllable over a CCT control range of at least 500 K within the range of 1800 to 6500 K.

[0130] In an embodiment, the control system 300 may be configured to control the color rendering index of the system light 1001 (in the first mode of operation) to a value of at least 90.

[0131] Controlling the spectral power distribution of the system light 1001 (in the operational mode) may include individually controlling the duty cycle of the first pulse and the duty cycle of the second period.

[0132] In particular, n≧3.

[0133] In an embodiment, the control system 300 may be configured to control the R9 value of the system light 1001 (in the first mode of operation) to a value of at least 40, or even higher, such as at least 50. As can be derived from Figs. 3b-3c, luminescent materials may be useful to increase the R9. The R9 value may be controllable over an R9 control range of at least 30. In particular, the R9 control range at least partially overlaps with a range of at least 40. In an embodiment, the color rendering index of the system light 1001 (in the first mode of operation) may be at least 80.

[0134] In Figures 3b-3c, the spectral power distribution of a black body radiator (emission) at a particular temperature is shown as a solid line from the bottom left to the top right.

[0135] Fig. 4 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. 4 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 system 1000. Thus, Fig. 4 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 the 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 numeral 1201. The illumination device light 1201 may essentially consist of the system light 1001, and therefore may be the system light 1001 in certain embodiments.

[0136] The term "plurality" refers to two or more.

[0137] 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.

[0138] The term "comprises" also includes embodiments in which the term "comprises" means "consisting of."

[0139] 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."

[0140] 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.

[0141] 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.

[0142] 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.

[0143] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

[0144] 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.

[0145] The singular reference of an element does not exclude the presence of a plurality of such elements.

[0146] 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.

[0147] 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.

[0148] 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.

[0149] 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-generation system comprising: n first vertical cavity surface-emitting lasers; a second light-generating device; and a control system, wherein n≧1; the second light-generating device is configured to generate a second light-generating device light; each of the n first vertical cavity surface-emitting lasers is configured to generate a first laser light varying between at least two centroid wavelengths having a wavelength difference of at least 10 nm with a variation frequency of at least 50 Hz; the control system is configured to control the n first vertical cavity surface-emitting lasers such that a system light is generated, the system light including the second light-generating device light and the first laser light of at least one of the n first vertical cavity surface-emitting lasers; the control system is configured to control a spectral power distribution of the system light; and the system light is white light having a correlated color temperature in the range of 1800K to 8000K and a color rendering index of at least 70.

2. 2. The light generation system of claim 1 , wherein each of the n first vertical cavity surface emitting lasers is configured to generate a first laser light varying between at least two centroid wavelengths having a wavelength difference of at least 20 nm, at least one of the n first vertical cavity surface emitting lasers is configured to generate a first time period of first laser light having a first centroid wavelength and a second time period of first laser light having a second centroid wavelength, each at a period frequency of at least 50 Hz, and the at least one of the n first vertical cavity surface emitting lasers is configured to provide the first laser light averaged over time as an emission band, the first laser light having a time-dependent centroid wavelength that varies over time between the first and second centroid wavelengths, and a spectral power distribution of the time-averaged first laser light is conformal to at least a portion of a spectral power distribution of an emission of a black body radiator at a particular correlated color temperature in a range of 1800 to 8000 K.

3. 3. The light generation system of claim 1, comprising at least two first vertical cavity surface emitting lasers configured to generate first laser light varying between the at least two centroid wavelengths in at least two different wavelength ranges, the wavelength ranges overlapping by less than 50%.

4. 3. The light generation system of claim 1, comprising at least three vertical cavity surface emitting lasers configured to generate first laser light having different time-averaged centroid wavelengths selected from a wavelength range of the group of 440 to 495 nm, 495 to 570 nm, 570 to 590 nm, 590 to 620 nm, and 620 to 780 nm, wherein the at least three time-averaged centroid wavelengths differ from each other by at least 40 nm.

5. 3. The light-generating system of claim 1, wherein the n first vertical cavity surface-emitting lasers are configured to generate system light having radiant flux at at least four different wavelengths in a wavelength range of 380 to 780 nm, and wherein minimum and maximum wavelengths at which the n first vertical cavity surface-emitting lasers provide intensity span a wavelength range of at least 110 nm, and at least 50% of the radiant flux of the first laser light averaged over time is in the at least four different wavelength ranges in the range of 380 to 780 nm.

6. 3. The light generation system of claim 1, wherein at least one of the n first vertical cavity surface emitting lasers is configured to generate a first laser light, and at least 60% of the radiant flux of the first laser light, averaged over time, is within at least eight different non-overlapping wavelength ranges of at least 10 nm wide within a range of 380 to 780 nm.

7. 5. The light generation system of claim 4, wherein all of the n first vertical cavity surface emitting lasers are configured to generate a first laser light together, and at least 80% of the radiant flux of the first laser light, averaged over time, is in at least 11 different non-overlapping wavelength ranges at least 10 nm wide within a range of 380 to 780 nm.

8. 3. The light-generating system of claim 1, further comprising a luminescent material configured to convert at least a portion of the light of the second light-generating device, the system light comprising luminescent material light, the luminescent material light having an emission band with a full width at half maximum of at least 40 nm.

9. 3. The light generating system of claim 1, further comprising a luminescent material configured to convert at least a portion of light of at least one of the n first vertical cavity surface emitting lasers, wherein the system light comprises luminescent material light, and the luminescent material light has an emission band with a full width at half maximum of at least 40 nm.

10. The luminescent material is ３ B ５ O １２ 10. The light generating system of claim 9, comprising a luminescent material of the A:Ce type, 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.

11. 3. The light generation system of claim 1, further comprising a third light generating device configured to generate a third device light, the third light generating device having a laser, the third device light having a third device light centroid wavelength at a fixed position, the n first vertical cavity surface emitting lasers configured to generate first laser light having a time-averaged centroid wavelength, the third device light centroid wavelength being different from at least one of the time-averaged centroid wavelengths of the first laser light of the n first vertical cavity surface emitting lasers.

12. 3. The light generating system of claim 1, wherein 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, 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.

13. 3. The light generating system of claim 2, wherein the control system is configured to control a color rendering index of the system light to a value of at least 90, and wherein controlling the spectral power distribution of the system light comprises independently controlling a duty cycle of a first pulse and a duty cycle of the second period.

14. 3. The light generating system of claim 1 , wherein n≧3, the control system is configured to control an R9 value of the system light to a value of at least 40, the R9 value being controllable over an R9 control range of at least 30, the R9 control range at least partially overlapping a range of at least 40, and 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, a disinfection device, a photochemical reactor, and an optical wireless communication device, comprising a light generation system according to any one of claims 1 to 2.

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