Transmission-type non-refrigeration passive athermalization long-wave infrared optical system

Abstract

The invention provides a transmission-type non-refrigeration passive athermalization long-wave infrared optical system. According to the optical system, the chalcogenide glass caliber is small, and the optical system has the optical passive athermalization performance and can be used for a non-refrigeration long-wave infrared detector in the 8 micron-12 micron long-wave infrared band. According to the technical scheme, infinite parallel light enters a crescent positive lens (3) with the maximum caliber from an object plane through a spherical cover, so that convergent light is formed; the convergent light enters a crescent negative lens (4), so that the convergence angles are reduced, and part of chromatic aberrations, thermal aberrations and monochromatic aberrations are corrected; the convergence angles are increased through a second crescent positive lens (5) which is purely spherical; through a concave surface negative lens (6) behind the second crescent positive lens (5), the thermal aberrations are balanced, the monochromatic aberrations are reduced, and the convergence angles of the light are reduced; the light enters a rear set, which is a biconvex positive lens (7), of a Petzval structure, and the residual chromatic aberrations, thermal aberrations and monochromatic aberrations of the system are balanced furthermore; imaging is conducted on a detector focal plane (8), and the whole imaging process is completed.

Description

technical field [0001] The invention relates to a transmission type uncooled passive athermalization long-wave infrared optical system, especially a transmission type optical system capable of optical passive athermalization performance in the 8μm-12μm long-wave infrared band and the temperature range of -45-60°C. Background technique [0002] When the optical instrument is used in a large temperature range, the thermal expansion and contraction of the lens barrel material, the optical material, and the temperature refractive index coefficient of the optical material will change the focal power of the lens, resulting in defocusing and deteriorating the imaging quality. Especially for infrared optical systems, due to the commonly used infrared optical materials, such as germanium materials, the refractive index temperature coefficient dn / dT is as high as 386×10-6 / K, which is nearly 80 times that of visible light glass dn / dT, and has a large When changing, the refractive index...

AI Technical Summary

Problems solved by technology

The corresponding shortcomings are either that the binary optical surface is more difficult in the processing, detection and processing of the optical system, or the performance of the large-aperture chalcogenide glass lens material is unstable, and the processing and coating of the optical system are difficult, and like The quality is easily affected by the non-uniformity of large-aperture chalcogenide glass lens materials. If you want to obtain large-aperture chalcogenide glass materials with better optical properties such as non-optical uniformity, striae degree, stress birefringence and other parameters, the price is relatively expensive.

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