Multiple-laser light source

Abstract

A light source includes a plurality of laser diodes or other light emitters. Beams of light from the light emitters are steered to provide n array of parallel beams that illuminate a target area with an array of patches of light. In some embodiments the parallel beams are de-magnified to form the array of patches of light. Such a light source has application in illuminating dynamically-addressable focusing elements such as phase modulators, deformable mirrors and dynamically addressable lenses. Light projectors for a wide variety of applications may combine a light source as described herein with a dynamically-addressable focusing element to project defined patterns of light.

1 . (canceled) 
     
     
         2 . A method for aligning an optical apparatus, the method comprising:
 positioning a light emitter in approximate alignment with a corresponding lens;   applying a flat phase pattern to a dynamic diffractive optical element in a path of a light beam emitted by the light emitter and focusing the beam by moving the light emitter relative to the dynamic diffractive optical element;   sampling a profile of the beam at plural distances along an optical axis and adjusting a distance between the light emitter and the lens until all the sampled profiles have equal widths;   inserting a polarizer into a light path of the beam and adjusting an angle of the light emitter to maximize a brightness of the beam;   applying an alignment pattern to the dynamic diffractive element and adjusting a position of the light emitter in one or more of XZ-plane parallelism, YZ-plane parallelism, rotation about the X or Y axis until the alignment pattern is registered.   
     
     
         3 . A method for aligning a light source comprising a plurality of lasers spaced in an arrangement, each of the lasers operable to emit a beam of light, the method comprising:
 centering and collimating each of the beams of light by positioning one or more lenses in an optical path of the beam of light and fixing a position of the one or more lenses;   positioning mirrors to redirect the beams of light to provide a closely spaced array of parallel beams of light and fixing positions of the mirrors.   
     
     
         4 . The method of  claim 3  wherein positioning the mirrors comprises reducing a spacing between adjacent ones of the beams of light emitted from the plurality of lasers. 
     
     
         5 . The method of  claim 4  comprising positioning the mirrors to clip edges of the beams of light emitted from the plurality of lasers. 
     
     
         6 . The method of  claim 5  wherein the mirrors comprise a plurality of knife-edge mirrors and each of the beams is reflected by two of the plurality of knife-edge mirrors arranged at 90 degrees to one another. 
     
     
         7 . The method of  claim 3  wherein positioning the mirrors comprises adjusting an angle of each of the plurality of mirrors about a corresponding pivot joint. 
     
     
         8 . The method of  claim 7  comprising, after each of the mirrors is positioned, fixing the corresponding pivot joint with an adhesive. 
     
     
         9 . The method of  claim 3  wherein positioning the mirrors comprises mounting each of the plurality of mirrors on a flexible structure. 
     
     
         10 . The method of  claim 9  comprising shimming the flexible structure into place. 
     
     
         11 . The method of  claim 3  comprising applying a settable material to fix the positions of the one or more lenses. 
     
     
         12 . The method of  claim 11  wherein the settable material comprises epoxy, glue or solder. 
     
     
         13 . The method of  claim 3  comprising positioning a diffraction grating in an optical path of the lasers to produce an alignment pattern. 
     
     
         14 . The method of  claim 3  comprising controlling a dynamic optical element positioned in an optical path of the lasers to display a dynamically varying diffractive alignment pattern. 
     
     
         15 . The method of  claim 14  comprising controlling the dynamic optical element to display progressively finer alignment patterns. 
     
     
         16 . The method of  claim 3  comprising positioning one or more additional lenses or mirrors to expand or contract the beam of light emitted from a corresponding one of the lasers. 
     
     
         17 . The method of  claim 3  comprising equalize path lengths of the beams of light by positioning one or more additional mirrors to fold a light path of one or more of the beams of light. 
     
     
         18 . The method of  claim 3  comprising placing cooling elements proximate to heat-generating elements of the light source. 
     
     
         19 . The method of  claim 3  comprising arranging the lasers in a two-dimensional array that has a length and a width wherein the length of the array is larger than a length of the closely spaced array of parallel beams and the width of the array is larger than a width of the closely spaced array of parallel beams. 
     
     
         20 . The method of  claim 3  wherein the lasers comprise laser diodes. 
     
     
         21 . The method of  claim 20  wherein the laser diodes are provided by at least one laser diode bar comprising a plurality of spaced-apart laser diodes.