MULTIPLE-LASER LIGHT SOURCE
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.