INFRARED CATADIOPTRIC LENS Russian patent published in 2015 - IPC G02B17/08 

FIELD: physics.

SUBSTANCE: lens consists of, arranged on a beam path, a first component comprising two aspherical mirrors, the first of which has a centre hole and is concave and the second is convex, and a second component comprising a first negative, a second positive and a third negative convex-concave lens, wherein the optical power of the second component is positive overall. An intermediate image is formed between the first and second components. The exit pupil is situated between the second component and the image plane.

EFFECT: high image quality owing to high resolution due to a greater aperture ratio, and improved image contrast and illumination due to optimum interfacing of the lens with a cooled radiation detector array.

1 dwg, 3 tbl