Compact type medium wave infrared dual-viewing-field optical system

Abstract

The invention relates to an optical system, and discloses a compact type medium wave infrared dual-viewing-field optical system. The compact type medium wave infrared dual-viewing-field optical system comprises a front set lens and a rear set lens. The front set lens comprises a first lens (1). The rear set lens comprises a second lens (2) and a third lens (3). The first lens (1) is a positive lens. The second lens (2) is a negative lens. The third lens (3) is a positive lens. According to the rear set lens of the telephoto optical system, the negative lens (germanium) and the positive lens (silicon) are combined. After the combination, a chromatic value of the rear set lens is larger. Chromatic aberration generated by the front set lens of the telephoto system can be eliminated. The diameter of the rear set lens is greatly compressed. The weight of the lenses is reduced. According to the fact that the medium wave infrared dual-viewing-field refrigerating optical system is designed, a shoot-in and shoot-out mode is adopted, the effect of zoom of the viewing field is achieved, a structure is compact, weight is light, and manufacturability is good.

Description

technical field [0001] The invention relates to an optical system, in particular to a compact mid-wave infrared dual-field optical system. Background technique [0002] At present, in the design of mid-wave infrared telephoto objectives in the past, there are mainly two methods to eliminate chromatic aberration: (1) The front group lens and the rear group lens are respectively achromatic (by combining positive and negative lenses or using binary optical devices, etc.) Realization), this method requires at least 4 lenses, and the large number of lenses will increase the attenuation of the signal through the optical system, and the achromatic negative lens germanium appears in the front group of lenses. The weight of the system is significantly increased; the binary optical device is achromatic, although the use of binary optical device achromatic does not increase the weight of the system, but because the diffraction efficiency of the binary diffraction surface cannot reach 1...

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Problems solved by technology

[0003] The present invention aims at the disadvantages in the prior art that the lens diameter of the first method is large, which leads to a significant increase in the weight of the system or a large energy loss, and the shortcomings of the poor manufacturability of the system in the second method. Under certain conditions, the compact mid-wave infrared dual-field optical system can still guarantee mutual achromatism with the front group

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