Ellipticized Infrared Lens Providing Balanced Astigmatism.
Patent, Filed 9 Apr 80, patented 26 Jan 82,
DEPARTMENT OF THE NAVY WASHINGTON DC
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An ellipticized singlet azimuth versus elevation optimized and aperture extremized nonspherical infrared lens of very low or even minimal F-number providing balanced astigmatism for wide angle infrared applications is described. The infrared lens has an elliptical periphery and surfaces defined by a system of nonlinear partial differential equations, the surfaces acting together to produce two perfect primary off-axis foci F and F at a finite distance in back of the lens and two perfect conjugate off-axis foci F at infinity and F at infinity in front of the lens at infinity i.e., the infrared lens simultaneously focuses energy from the primary foci F and F into two off-axis parallel ray plane wave beams directed towards infinity at equal but opposite angles with respect to the infrared lens axis. The infrared lens may be built of various materials such as vitreous quartz. Patents