| abstract |
Four embodiments of fast (F/2 or faster), wide angle (70*), infrared lens systems are disclosed. Each of the lens systems is formed of a plurality of thin, highly deformed germanium plates. Each highly deformed plate has two, substantially parallel, highly deformed aspheric surfaces. The high index of refraction of germanium generates the power in each lens system despite the substantially parallel nature of the aspheric surfaces of each plate, and the aspheric surfaces are utilized for the correction of aberrations. |