Low-cost refracting-reflecting athermalizing medium wave infrared lens

Abstract

The invention provides a low-cost refracting-reflecting athermalizing medium wave infrared lens and aims at providing a low-cost refracting-reflecting optical lens which is small in aspherical mirror number, low in cost, made of a small amount of aspherical lenses and conventional silicon and germanium optical materials at a 3.7-4.8 [mu]m medium-wave infrared band and having the optical passive athermalizing performance. The technical scheme is that parallel light enters a main reflection spherical mirror (3) to form a converged light beam through a spherical cover (2) in an incidence mode, a convergence angle is decreased through a Mangin refracting-reflecting mirror (4), a primary mirror face (5) is formed by decreasing a part of aberration and increasing a part of balanced aberration and negative thermal difference of a lens to be arranged behind, the light beam is changed into divergent light, the divergent light enters a negative lens (6) made of an aspherical germanium material and a positive meniscus lens (7) made of a silicon material so as to reduce chromatic aberration and aberration, then converges through a positive convex lens (8) made of the silicon material, enters a detector window (9) and finally forms an image on a detector focal plane (11) through a cold light diaphragm (10), and the whole imaging process is finished.

Description

technical field [0001] The invention relates to a low-cost catadioptric adiabatic mid-wave infrared lens, especially a low-cost reflex lens with optical passive athermalization performance, which adopts a spherical reflector and conventional optical materials in the 3.7 μm-4.8 μm mid-wave infrared band. Reverse optical lens. Background technique [0002] In existing catadioptric mid-wave infrared band optical systems, the primary and secondary mirror systems generally adopt a purely reflective Cassegrain RC structure, and aspheric surfaces are processed on the primary and secondary mirrors to expand the field of view; More than three lens materials, including relatively expensive materials such as zinc sulfide and zinc selenide, the system cost is high, and the accuracy of assembly and adjustment is high. [0003] The Chinese journal "Infrared Technology" Volume 26 No. 2, published in March 2004, titled "Infrared R-C Optical System Design", discloses a catadioptric mid-wave...

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Problems solved by technology

[0006] The purpose of the present invention is to aim at the above-mentioned prior art primary mirror or secondary mirror, or both primary and secondary mirrors are aspherical, and the aspheric surface has only one symmetry axis, which is symmetrical to the spherical axis of the spherical mirror, and its processing, detection and assembly are relatively difficult and difficult. To c

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