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

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.

What is claimed is: 
     
         1 . A lighting apparatus, comprising:
 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; and   wherein 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, wherein the phosphor element has an inner surface and an outer surface and a phosphor coating on at least one of the inner surface or outer surface.   
     
     
         2 . The lighting apparatus as recited in  claim 1 , wherein the second optical element is configured further to spread and project the coherent light over said phosphor element. 
     
     
         3 . The lighting apparatus as recited in  claim 1 , further comprising an optical fiber coupling the laser module with the phosphor capsule. 
     
     
         4 . The lighting apparatus as recited in  claim 3 , wherein the optical fiber passes through the concave mirror. 
     
     
         5 . The lighting apparatus as recited in  claim 4 , further comprising a protective tube surrounding the optical fiber. 
     
     
         6 . The lighting apparatus as recited in  claim 5 , wherein the protective tube is configured to be a mount for the phosphor capsule. 
     
     
         7 . The lighting apparatus as recited in  claim 1 , further comprising multiple laser modules coupled to a combiner, the combiner coupled to the optical fiber. 
     
     
         8 . The lighting apparatus as recited in  claim 7 , wherein the multiple optical modules are configured to produce coherent light of different chromaticities. 
     
     
         9 . The lighting apparatus as recited in  claim 1 , wherein the inner surface and outer surface of the phosphor element form a volume. 
     
     
         10 . The lighting apparatus as recited in  claim 1 , wherein the phosphor coating is on the inner surface of the phosphor capsule. 
     
     
         11 . The lighting apparatus as recited in  claim 1 , wherein the phosphor coating is on the outer surface of the phosphor capsule. 
     
     
         12 . The lighting apparatus as recited in  claim 1 , wherein the phosphor coating is on both the inner surface and the outer surface of the phosphor capsule. 
     
     
         13 . A method of steering light from a laser-excited phosphor element, comprising:
 producing coherent light;   providing the coherent light to a phosphor capsule located proximate a focus of a concave mirror;   causing the phosphor capsule to phosphoresce in response to the coherent light and produce resulting light, the resulting light being projected onto the concave mirror; and   steering the resulting light in a direction using the concave mirror;   wherein the phosphor capsule comprises at least a phosphor element positioned having an inner surface and an outer surface and a phosphor coating on at least one of the inner surface or outer surface.   
     
     
         14 . The method as described in  claim 13 , wherein the providing comprises causing the coherent light to pass through an optical fiber coupling the laser module and the phosphor capsule. 
     
     
         15 . The method as recited in  claim 14 , wherein the optical fiber passes through the concave mirror. 
     
     
         16 . The method as recited in  claim 14 , further comprising multiple laser modules coupled to a combiner, the combiner coupled to the optical fiber. 
     
     
         17 . The method as recited in  claim 16  wherein the multiple optical modules are configured to produce coherent light of different chromaticities. 
     
     
         18 . The method as recited in  claim 13 , wherein the phosphor capsule further comprises a first optical element configured to spread the coherent light. 
     
     
         19 . The method as recited in  claim 18 , wherein the phosphor capsule further comprises a second optical element configured further to spread and project the coherent light over the phosphor element. 
     
     
         20 . The method as recited in  claim 13 , wherein the inner surface and the outer surface of the phosphor element form a volume.