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EP-4505110-B1 - LASER LIGHTING SYSTEM COMPRISING OPTICAL FIBER

EP4505110B1EP 4505110 B1EP4505110 B1EP 4505110B1EP-4505110-B1

Inventors

  • VAN BOMMEL, TIES
  • CORNELISSEN, HUGO JOHAN
  • HIKMET, RIFAT ATA MUSTAFA
  • VDOVIN, Olexandr Valentynovych

Dates

Publication Date
20260506
Application Date
20230328

Claims (15)

  1. A light generating system (1000) comprising a light generating device (100), an optical fiber (500), and a light generating unit (1400), wherein: - the light generating device (100) is configured to generate device light (101) comprising a first wavelength, wherein the light generating device (100) comprises a solid-state light source; - the optical fiber (500) comprises an elongated body of light transmissive material, transmissive for the device light (101) comprising the first wavelength; wherein the optical fiber (500) comprises a light entrance part (511); wherein the optical fiber (500) has a length L1 and an elongated outer surface (512) over at least part of its length L1; wherein the optical fiber (500) is configured such that upon irradiating the light entrance part (511) with the device light (101) comprising the first wavelength, over at least part of its length L1 second light (501) escapes from the optical fiber (500) via the elongated outer surface (512); - the light generating unit (1400) comprises a light chamber (400); wherein the light chamber (400) comprises a reflective internal surface (410), reflective for the second light (501), and a chamber exit window (420), transmissive for the second light (501); - at least part of the optical fiber (500) having a chamber fiber length L2 is configured within the light chamber (400) with n1 curvatures (550) in a plane parallel to a length axis (A) of the optical fiber (500), wherein n1≥1; - the light generating system (1000) is configured to generate system light (1001) comprising at least part of the second light (501), characterized by - the light generating system (1000) comprising two or more optical fibers (500) and two or more light generating devices (100), configured in two or more sets of each an optical fiber (500) and one or more light generating devices (100), wherein the light entrance part (511) is configured downstream from these one or more light generating devices (100), wherein spectral power distributions of the second light (501) of two or more optical fibers (500) are different; wherein the light generating system (1000) further comprises a control system (300) configured to control a spectral power distribution of the system light (1001), wherein the system light (1001) comprises at least part of the second light (501) of one or more optical fibers (500).
  2. The light generating system (1000) according to claim 1, wherein the solid-state light source (100) comprises a laser.
  3. The light generating system (1000) according to any one of the preceding claims, wherein the solid-state light source (100) comprises a diode laser, and wherein the device light (101) comprises diode laser light; and wherein the system light (1001) comprises one or more of: - device light (101), and - converted device light (201), wherein the optical fiber (500) comprises a luminescent material (200) configured to convert at least part of the device light (101) into the converted device light (201).
  4. The light generating system (1000) according to claim 3, wherein the optical fiber (500) comprises a core (502) comprising the light transmissive material, and a cladding (503) surrounding the core (502), wherein the optical fiber (500) further comprises light outcoupling elements (510); wherein the cladding comprises the luminescent material (200); wherein the device light (101) comprises one or more of UV light and blue light, and wherein the system light (1001) is white light.
  5. The light generating system (1000) according to any one of the preceding claims, wherein the light chamber (400) comprises an internal chamber length, L3, and an internal chamber width, W3; wherein L2>(π*sqrt(L3*W3)).
  6. The light generating system (1000) according to claim 5, wherein L2≥3*(π*sqrt(L3*W3)).
  7. The light generating system (1000) according to any one of the preceding claims, wherein the optical fiber (500) has a fiber diameter, D1, wherein the n1 curvatures (550) have curvature radii, Rc, wherein Rc<10*D1.
  8. The light generating system (1000) according to claim 7, comprising k1 curvatures (550) per square centimeter, wherein k1>10.
  9. The light generating system (1000) according to any one of the preceding claims 7-8, wherein the curvatures (550) are arranged such that an area Ai of the Voronoi cells from a 2D Voronoi tessellation of an area comprising a projection of the curvatures (550) is selected from the range of 0.7-1.3 times the average area of all the Voronoi cells in the 2D Voronoi tessellation.
  10. The light generating system (1000) according to any one of the preceding claims, wherein the optical fiber (500) is configured in one or more of a meandering configuration, a stacked configuration, spiral configuration, and an interleaved configuration.
  11. The light generating system (1000) according to any one of the preceding claims, wherein part of the optical fiber (500) is configured external from the light chamber (400); and wherein during operation of the light generating device (100), at least part of the second light (501) escapes from the optical fiber (500) external from the light chamber (400).
  12. The light generating system (1000) according to any one of the preceding claims, comprising a plurality of light generating units (1400), wherein at least two light generating units (1400) share the same optical fiber (500).
  13. The light generating system (1000) according to any one of the preceding claims, comprising two or more optical fibers (500) and two or more light generating devices (100), configured in two or more sets of each an optical fiber (500) and one light generating device (100), wherein the light entrance part (511) is configured downstream from these one or more light generating devices (100), wherein spectral power distributions of the second light (501) of two or more optical fibers (500) are different; wherein the light generating system (1000) further comprises a control system (300) configured to control a spectral power distribution of the system light (1001), wherein the system light (1001) comprises at least part of the second light (501) of one or more optical fibers (500).
  14. The light generating system (1000) according to any one of the preceding claims, wherein the light chamber (400) comprises a cross-sectional shape selected from the group of circular, elliptical, rectangular and n-gonal, wherein n is at least 5; wherein the chamber exit window (420) comprises a diffuser for the second light (501); wherein the reflective internal surface (410) is diffusively reflective.
  15. A lighting device (1200) selected from the group of a lamp (1) and a luminaire (2), comprising the light generating system (1000) according to any one of the preceding claims.

Description

FIELD OF THE INVENTION The invention relates to a light generating system comprising an optical fiber. The invention further relates to a lighting device comprising the light generating system. BACKGROUND OF THE INVENTION Optical fiber based lighting systems are known in the art. WO2021040623A1, for instance, describes an optical fiber that includes a core region having a scattering structure defined therein, the scattering structure being twisted about a longitudinal axis of the core region, wherein the scattering structure is configured to scatter light propagating in the optical fiber out of the optical fiber. A lighting apparatus having the optical fiber and a method for forming the optical fiber are also described in WO2021040623A1. US2010/238374A discloses backlight with a fiber lamp. The fiber lamp has a side-emitting fiber with a core layer for guiding light and a cladding layer arranged around the core layer. The cladding layer allows light to be extracted from a surface of the cladding layer. A light source is arranged on one or both of a pair of end surfaces of the side-emitting fiber and emitting single-color light. A phosphor layer is arranged on the surface of the cladding layer. DE102006061164 discloses a light-emitting device comprising a radiation source for emitting radiation of at least a first wavelength and an elongated, curved light-conducting body into which the radiation emitted by the radiation source is coupled and which, due to the coupled-in radiation of the first wavelength, decouples light at an angle to its longitudinal axis. SUMMARY OF THE INVENTION The use of optical fibers to transmit light is known in the art. However, light generating systems that utilize transmission of light from the surface of the optical fiber are still actively developed. Light generating systems known in the art may require additional light sources to be configured within the system. This may be disadvantageous as the light sources may have to be housed within such a light generating system. This may lead to: (i) undesirable heating of the system, (ii) a requirement to route power to the system, and (iii) cumbersome maintenance in case of malfunction. The use of laser light sources is known in the art, however, providing lighting distributed over a region of space using a single laser light source (for example: in an office, a room, a car) is still a challenge. Providing lighting systems within building materials such as concrete walls or between glass panels is difficult, especially if light sources and power supply units have to (also) be configured in these locations. Mixing light from different sources to provide a plurality of light of different colors, wavelengths and spectral power distributions may require using a plurality of light sources, which may increase the complexity of the system (due to the large number of elements that have to be configured within it). Using a plurality of light sources may make the light generating system bulky and may be difficult to maintain. This may be disadvantageous, especially when the light generating systems are configured in a less than ideal locations for example: within building materials, in the lining of car interiors, etc. Hence, it is an aspect of the invention to provide an alternative light generating system, which preferably further at least partly obviates one or more of above-described drawbacks. The present invention may have as object to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative. According to a first aspect, the invention provides a light generating system ("system"). In embodiments, the light generating system may comprise a light generating device ("device"). Especially, the light generating system may comprise an optical fiber. The light generating system, in embodiments, may comprise a light generating unit. Hence, in embodiments, the light generating system may comprise a light generating device, an optical fiber, and a light generating unit. Further, in embodiments, the light generating device may be configured to generate device light. Especially in embodiments, the device light may comprise a first wavelength. In embodiments, the light generating device may comprise a solid-state light source. In embodiments, the optical fiber may comprise an elongated body of light transmissive material. Additionally, the elongated body of light transmissive material may be transmissive for the device light comprising the first wavelength. Further, the optical fiber may comprise a light entrance part. In embodiments, the optical fiber may have a length L1 (or total fiber length). Further, in embodiments, the optical fiber may comprise an elongated outer surface over at least part of its length L1. The light entrance part of the optical fiber may be irradiated with the device light. Especially, the optical fiber may be configured such that upon irradiating the light entrance part wi