Optical projection system and method for a cooled light source

Abstract

A light projection optical system is presented. The system comprises a cooling chamber containing: a light source operative at a cool temperature being lower than 240K; a cooler unit capable of cooling said light source to said cool temperature during the light source operation, an optical window permitting light emergence outside from the cooling chamber; and an optical unit accommodated in the optical path of light emitted by said light source and enabling emergence of this light through said optical window outside from the cooling chamber.

1 . A laser module comprising:
 a support assembly comprising at least two spaced-apart compartments each containing at least one semiconductor laser, and   an optical unit comprising optical elements mounted at the output facets of said compartments so as to be in optical paths of laser beams emitted by said lasers.   
     
     
         2 . The laser module of  claim 1 , configured to be mountable inside a chamber of an inner diameter being less than 3 cm. 
     
     
         3 . The laser module of  claim 1 , wherein said optical unit comprises at least one converging lens. 
     
     
         4 . The laser module of  claim 1 , wherein each of said compartments contains an array of the lasers, a corresponding array of the optical elements being located at the output of said compartment. 
     
     
         5 . The laser module of  claim 1 , wherein said optical unit includes a plurality of lenses. 
     
     
         6 . The laser module of  claim 1 , wherein each of the lenses is associated with a corresponding one of lasers. 
     
     
         7 . The laser module of  claim 1 , wherein the optical elements carry out one of the following: collimation, focusing, and reducing the beam divergence. 
     
     
         8 . The laser module of  claim 1 , wherein the optical elements focus at least one laser beam in one or two dimensions. 
     
     
         9 . The laser module of  claim 1 , wherein said at least two compartments contain multiple semiconductor lasers arranged in a one-, two-, or three-dimensional array. 
     
     
         10 . The laser module of  claim 1 , comprising at least one monolithic semiconductor laser bar. 
     
     
         11 . The laser module of  claim 1 , wherein the semiconductor lasers comprise at least one laser emitting in at least one of mid and far infrared wavelength range. 
     
     
         12 . The laser module of  claim 1 , wherein said the semiconductor lasers comprise at least two lasers having substantially different emission spectra. 
     
     
         13 . The laser module of  claim 1 , wherein said semiconductor laser emit at least two laser beams and said optical unit is configured for projecting the at least two beams to propagate along at least two substantially parallel axes. 
     
     
         14 . The laser module of  claim 13 , wherein said at least two substantially parallel laser beams comprise beams with directions diverging not more than 1 degree. 
     
     
         15 . The laser module of  claim 1 , wherein said semiconductor lasers emit at least two laser beams and said optical unit is configured for focusing said at least two laser beams into intersecting focus spots. 
     
     
         16 . The laser module of  claim 1 , wherein said optical elements are made from at least one of the following materials: germanium, ZnSe, ZnS, CaF 2 , silicon, sapphire, fused silica, and quartz. 
     
     
         17 . The laser module of  claim 1 , wherein said semiconductor lasers comprise a laser emitting in 3-5 micron wavelength range. 
     
     
         18 . The laser module of  claim 1 , wherein said semiconductor lasers comprise a Quantum Cascade Laser. 
     
     
         19 . The laser module of  claim 1 , wherein said semiconductor lasers comprise an InP based laser with AlInAs/GaInAs active layers. 
     
     
         20 . A cooling chamber for use in cooling a semiconductor laser based light source, wherein:
 the cooling chamber has an inner diameter less than 3 cm, and   a laser module is mounted in the cooling chamber, said laser module comprising: a support assembly comprising at least two spaced-apart compartments each containing at least one semiconductor laser, and an optical unit including optical elements mounted at the output facets of said compartments.