Multi-mode optical imager

Abstract

A common aperture, multi-mode optical imager for imaging electromagnetic radiation bands from a field of two or more different wavelengths is described. Fore-optics are provided to gather and direct electromagnetic radiation bands forming an image into an aperture of the multi-mode optical imager. The image is divided into two different wavelength bands, such as visible light and long-wave infrared. The first wavelength band (e.g., visible light) is detected by a first detector, such as a CCD array, for imaging thereof. The second wavelength band (e.g., long-wave infrared) is detected by a second detector, such as an uncooled microbolometer array, for imaging thereof. Additional optics may be provided for conditioning of the first and second wavelength bands, such as such as for changing the magnification, providing cold shielding, filtering, and/or further spectral separation.

1 . A microbolometer detector, comprising: 
 a microbolometer array for detecting a long-wave infrared band; and    micro-optics having an array of reflective concentrators, each of the reflective concentrators adjacent one bolometer of the microbolometer array for matching an f-number of infrared radiation to a desired f-number of the bolometer.    
   
   
       2 . The microbolometer detector of  claim 1 , the concentrators having a compound-parabolic shape.  
   
   
       3 . The microbolometer detector of  claim 1 , the concentrators comprising high-index germanium.  
   
   
       4 . The microbolometer detector of  claim 1 , the micro-optics comprising one or more refractive elements transmissive to the long-wave infrared band, each of the elements being adjacent to one bolometer of the microbolometer array.  
   
   
       5 . The microbolometer detector of  claim 1 , wherein the micro-optics comprise an array of hollow tapered capillaries.  
   
   
       6 . The microbolometer detector of  claim 5 , further comprising a reflective coating on an inside surface of the hollow tapered capillaries.  
   
   
       7 . The microbolometer detector of  claim 1 , wherein the micro-optics comprise one or more of a fiber optic taper, one or more refractive lens elements, and reflective elements.  
   
   
       8 . The microbolometer detector of  claim 1 , further comprising a housing encasing the detector, except for a region of aperture.  
   
   
       9 . The microbolometer detector of  claim 1 , the microbolometer array comprising an uncooled microbolometer array.  
   
   
       10 . The microbolometer detector of  claim 9 , wherein the micro-optics are disposed proximal to the uncooled microbolometer array to reduce the f-number of the long-wave infrared band incident to the uncooled microbolometer array.  
   
   
       11 . The microbolometer detector of  claim 1 , further comprising a controller responsive to a command signal to displace the micro-optics laterally across the microbolometer array, to shutter the array.  
   
   
       12 . The microbolometer detector of  claim 11 , further comprising a piezo-electric element responsive to the command signal to shift the micro-optics laterally across the microbolometer array, to shutter the array.