Method and apparatus for collimating light from a laser-excited phosphor element

a laser-excited phosphor element and collimation method technology, applied in lighting and heating apparatus, light source combinations, instruments, etc., can solve the problems of high cost, high cost, and inability to control output light, so as to achieve a high degree of collimation and improve the effect of approximating full-spectrum ligh

Inactive Publication Date: 2018-11-15
STONE KEVIN
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

This approach enables more efficient production and control of light, enhancing optical efficiency and allowing for full-spectrum light generation, particularly beneficial in applications like searchlights, theatrical fixtures, and cinema lighting, by overcoming the limitations of existing technologies.

Problems solved by technology

This makes emission of full spectrum white light from an LED-only illuminator highly impractical, as doing so would require tens of different-wavelength emitters.
This approach also has its drawbacks, in that the spectral output profile is characterized by a spike at the center of the LED's emission band surrounded by a roughly 10 nm half-height curve, then a broad but lower amplitude band (as compared with the LED output) from the secondary phosphor emission, typically representing one-quarter to one-third of the visible spectrum, which then trails off to near zero emission at the lower visible frequencies, resulting in an approximate “white light” output that is deficient in the green and red bands.
LEDs also present significant issues in controllability of output light due to the planar configuration of the emitter.
With current available LED output coupled with practical luminaire size constraints, beam collimation is typically limited to no tighter than 8° without significant loss of optical efficiency.
This makes LEDs relatively inefficient sources for imaging optical systems and especially for collimating systems such as searchlights and spots.
Lasers were also difficult to cool and also exhibit narrow band emission patterns similar to those of LEDs.
While LEDs may also be combined via combiners such as dichroic “x-cubes,” efficiency is compromised by the limited ability to collimate the output from the individual emitters.
This results in significant portions of the beams from these emitters striking dichroic elements off-axis, thereby limiting the efficiency of the reflectivity of the dichroic elements and resulting in light loss.

Method used

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  • Method and apparatus for collimating light from a laser-excited phosphor element
  • Method and apparatus for collimating light from a laser-excited phosphor element
  • Method and apparatus for collimating light from a laser-excited phosphor element

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first embodiment

[0023]FIG. 1A is a diagram of an apparatus for steering light from a laser-excited phosphor element. A laser module 110 is configured to generate coherent light. The coherent light is projected from the laser module 110 into an optical fiber 120, which may be located in a protective tube 130. The protective tube 130 may be employed as a mount for a phosphor capsule 140. The optical fiber 120 conveys the coherent light to the phosphor capsule 140, where the laser is then projected into and spread by optical elements (not shown in FIG. 1A) onto a phosphor element 150 located proximate the center axis 160 of a concave mirror 170.

[0024]Excitation by the coherent light causes the phosphor element 150 to phosphoresce and produce resulting light. The resulting light produced by the phosphor element 150 is projected upon the mirror 170. The mirror 170 is configured to steer the resulting light to be dispersed in a general direction. In the illustrated embodiment, the mirror 170 is a parabol...

second embodiment

[0033]FIG. 2 is a diagram of an apparatus for steering light from a laser-excited phosphor element. FIG. 2 includes many elements in common with FIG. 1A. Those elements have the same reference numerals and will not be described in conjunction with FIG. 2. While the embodiment of FIG. 1A employed a single laser module 110, other embodiments of the apparatus employ multiple laser modules. The specific embodiment of FIG. 2 employs three laser modules 210a, 210b, 210c. Optical fibers 220a, 220b, 220c are coupled to respective ones of the laser modules 210a, 210b, 210c as FIG. 2 shows. The optical fibers 220a, 220b, 220c are also coupled to a combiner 220. In one embodiment, the combiner 220 is a dichroic x-cubes. The optical fiber 120, which provides coherent light to the phosphor capsule 140, is also coupled to the combiner 220.

[0034]In the embodiment of FIG. 2, the laser modules 210a, 210b, 210c each provide coherent light of different chromaticity (i.e. wavelength). In one embodiment...

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Abstract

A lighting apparatus and method of steering light from a laser-excited phosphor element are disclosed herein. In one embodiment, the lighting apparatus includes: a laser module configured to generate coherent light; a concave mirror; and a phosphor capsule located proximate a focus of the concave mirror and configured to receive and phosphoresce in response to the coherent light and project resulting light upon the concave mirror, the concave mirror configured to direct the resulting light in a direction. The phosphor capsule comprises at least a first optical element configured to spread coherent light within the phosphor capsule, a second optical element opposite the first optical element, and a phosphor element positioned between the first optical element and the second optical element, phosphor element having an inner surface and an outer surface and a phosphor coating on at least one of the inner surface or outer surface.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application is a continuation of U.S. patent application Ser. No. 15 / 368,492 filed by Kevin Stone on Dec. 2, 2016, entitled “Method and Apparatus for Collimating Light from a Laser-Excited Phosphor Element” which, in turn, is a continuation-in-part of U.S. patent application Ser. No. 14 / 828,137 filed by Kevin Stone on Aug. 17, 2015, entitled “Method and Apparatus for Collimating Light from a Laser-Excited Phosphor Element,” which, claimed the benefit of U.S. Provisional Application Ser. No. 62 / 038,526, filed by Kevin Stone on Aug. 18, 2014, entitled “Method and Apparatus for Collimating Light from a Laser-Excited Phosphor Element.” All prior applications are commonly owned with this application and incorporated herein by reference.TECHNICAL FIELD[0002]This application is directed, in general, to lighting sources and, more specifically, to lighting sources employing laser-excited phosphor elements.BACKGROUND[0003]Increasing demand for ...

Claims

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Application Information

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Patent Type & AuthorityApplications(United States)
IPC IPC(8): F21K9/64G02B27/10G02B6/42F21V8/00F21K9/61F21V7/08F21V7/06F21Y113/10
CPCG02B6/42G02B6/0008F21Y2113/10F21V7/08F21V7/06F21K9/61G02B6/0006F21K9/64G02B27/1006
InventorSTONE, KEVIN
OwnerSTONE KEVIN