Apparatus for wavelength conversion

Abstract

There is provided an apparatus for wavelength conversion, comprising a wavelength converter, a first reflector, a second reflector, a third reflector, and a first lens. The first reflector has a curvature and is configured to reflect a plurality of input light beams onto the second reflector. The second reflector is configured to reflect the input light onto the third reflector. The first lens is disposed between the wavelength converter and the third reflector. The third reflector is configured to reflect the input light through the first lens and onto the wavelength converter, which is then excited to emit an emitted light. The first lens is configured to receive at least a portion of the emitted light, reduce its divergence, and at least partially transmit it to form an output light propagating towards the third reflector, which is configured to at least partially transmit the output light.

1 . An apparatus for wavelength conversion, the apparatus comprising:
 a wavelength converter comprising a wavelength conversion material configured to absorb a first portion of one or more input light beams configured to excite the wavelength conversion material to emit an emitted light and to reflect a second portion of the one or more input light beams to form one or more unabsorbed light beams;   a base reflector, a differential reflector, a retro reflector, and a first lens, the first lens disposed between the wavelength conversion material and the differential reflector;   the wavelength conversion material, the differential reflector, the base reflector, and the retro reflector defining an unabsorbed light path extending from the wavelength conversion material, through the first lens, onto the differential reflector, onto the base reflector, and onto the retro reflector;   the base reflector configured to reflect the one or more input light beams onto the differential reflector;   the differential reflector configured to reflect the one or more input light beams through the first lens and onto the wavelength conversion material;   the first lens configured to receive at least a portion of the emitted light, to reduce a divergence of the portion of the emitted light, and to at least partially transmit the portion of the emitted light to form an output light propagating towards the differential reflector;   the differential reflector further configured to at least partially transmit the output light;   the first lens further configured to receive and transmit the one or more unabsorbed light beams propagating along the unabsorbed light path from the wavelength conversion material towards the retro reflector; and   the retro reflector configured to reflect the one or more unabsorbed light beams back towards the wavelength conversion material along the unabsorbed light path.   
     
     
         2 . The apparatus of  claim 1 , further comprising a second lens configured to receive the output light propagating from the first lens, the second lens configured to further reduce the divergence of the output light. 
     
     
         3 . The apparatus of  claim 2 , wherein the second lens comprises a flat side configured to receive the output light and a convex side opposite the flat side, the flat side being the differential reflector. 
     
     
         4 . The apparatus of  claim 3 , wherein the flat side comprises a dichroic coating configured to reflect the one or more input light beams and the one or more unabsorbed light beams and to transmit the output light. 
     
     
         5 . The apparatus of  claim 4 , further comprising a third lens configured to receive the output light propagating from the second lens, the third lens configured to further reduce the divergence of the output light. 
     
     
         6 . The apparatus of  claim 5 , wherein one or more of:
 the first lens comprises a first side configured to receive the portion of the emitted light, and a corresponding convex side opposite the first side; and   the third lens comprises a corresponding flat side configured to receive the output light from the second lens and a corresponding convex side opposite the corresponding flat side.   
     
     
         7 . The apparatus of  claim 6 , wherein the first side comprises one or more of:
 a corresponding flat side; and   a concave side.   
     
     
         8 . The apparatus of  claim 1 , wherein the wavelength conversion material is disposed on the base reflector. 
     
     
         9 . The apparatus of  claim 1 , wherein the first lens is spaced from the wavelength converter by a gap. 
     
     
         10 . The apparatus of  claim 9 , wherein the gap is in a range of about 1 mm to about 2 mm. 
     
     
         11 . The apparatus of  claim 1 , further comprising:
 a first reflector configured to reflect the one or more input light beams onto the base reflector, the first reflector having a shape configured to increase a convergence of the one or more input light beams reflected from the first reflector; and   the unabsorbed light path further defined by the first reflector wherein the unabsorbed light path extends from the wavelength conversion material, through the first lens, onto the differential reflector, onto the base reflector, onto the first reflector, and onto the retro reflector.   
     
     
         12 . The apparatus of  claim 11 , wherein the first reflector comprises one of a parabolic reflector, a stepped reflector, and a faceted reflector. 
     
     
         13 . The apparatus of  claim 11 , wherein the first reflector defines an aperture for passage of the output light. 
     
     
         14 . The apparatus of  claim 11 , wherein the first reflector, the base reflector, the differential reflector, and the first lens are configured to converge the one or more input light beams at the wavelength conversion material. 
     
     
         15 . The apparatus of  claim 11 , further comprising:
 a support;   a plurality of receiving banks disposed on the support, each receiving bank configured to receive light sources each configured to emit a corresponding one of the one or more input light beams; and   one or more further retro reflectors disposed on the support;   each given receiving bank having a corresponding retro reflector configured to reflect the one or more unabsorbed light beams generated by the one or more input light beams emitted by the light sources receivable in the given receiving bank.   
     
     
         16 . The apparatus of  claim 15 , wherein
 the support comprises an annular member;   the receiving banks and the retro reflectors are disposed radially on the annular member; and   the receiving banks and the retro reflectors disposed in an alternating arrangement on the annular member, each receiving bank disposed diametrically opposite a corresponding retro reflector.   
     
     
         17 . The apparatus of  claim 1 , wherein the wavelength conversion material comprises one of a phosphor and quantum dots. 
     
     
         18 . An apparatus for wavelength conversion, the apparatus comprising:
 a wavelength converter comprising a wavelength conversion material configured to absorb a first portion of an input light beam configured to excite the wavelength conversion material to emit an emitted light and to reflect a second portion of the input light beam to form an unabsorbed light beam;   a fourth reflector, a fifth reflector, and a fourth lens, the fourth lens disposed between the fourth reflector and the fifth reflector;   the fourth reflector configured to receive the unabsorbed light beam from the wavelength conversion material and to reflect the unabsorbed light beam through the fourth lens and onto the fifth reflector; and   the fifth reflector configured to receive the unabsorbed light beam from the fourth reflector and to reflect the unabsorbed light beam onto the wavelength conversion material to form a first retro reflected light beam.   
     
     
         19 . The apparatus of  claim 18 , further comprising:
 a sixth reflector and a fifth lens, the fifth lens disposed between the wavelength conversion material and the sixth reflector;   the wavelength conversion material further configured to absorbed a third portion of the first retro reflected light beam and to reflect a fourth portion of the first retro reflected light beam to form a second unabsorbed light beam propagating through the fifth lens and towards the sixth reflector;   the sixth reflector configured to reflected the second unabsorbed light beam through the fifth lens and onto the wavelength conversion material to form a second retro reflected light beam;   the wavelength conversion material further configured to absorb a fifth portion of the second retro reflected light beam and to reflect a sixth portion of the second retro reflected light beam to form a third unabsorbed light beam propagating towards the fifth reflector;   the fifth reflector further configured to reflect the third unabsorbed light beam through the fourth lens and onto the fourth reflector; and   the fourth reflector further configured to receive the third unabsorbed light beam from the fifth reflector and to reflect the third unabsorbed light beam onto the wavelength conversion material to form a third retro reflected light beam.   
     
     
         20 . The apparatus of  claim 18 , wherein one or more of the fourth lens and the fifth lens comprises a biconvex lens.