Patent ID: 7082001
Filing Date: 2006-07-25
Classification: G02B

Abstract:
1. A dual mode mirror imaging system comprising: a Cassegrain-type objective assembly having a primary mirror with a hole in its center, and a secondary mirror spaced in front of the primary mirror; and imager optics disposed in the hole in the center of the primary mirror, the imager optics has five lenses wherein three of lenses are made from gallium arsenide and one of the lenses is a diffractive lens with a center wavelength of 4.1 microns, the secondary mirror adapted to receive laser wavelength light and infrared wavelength light reflected from the primary mirror and to reflect the light back through the imager optics to a focal plane, the secondary mirror having one reflecting surface for the laser light and another reflecting surface for the infrared light; the pair of reflecting surfaces positioned to change the optical path length between the laser light and the infrared light so that the laser light and the infrared light are imaged at the same focal plane without defocusing.