Diffractive optical imaging lens systems

Abstract From the Canadian patent

Abstract, A diffractive imaging lens, has a diffractive optical element and an aperture stop remote from the lens in the direction of the object to be imaged which corrects the lens for coma, astigmatism, and field curvature and which can be corrected for spherical aberration by using a phase corrector in the aperture of the stop. The lens provides monochromatic imaging performance superior to conventional systems, both glass lenses and holographic lenses of similar complexity. The lens system may be provided in anamorphic configuration.