Broad wave band, large view field and large aperture coude three reflection afocal optical system

Abstract

The invention discloses a broad wave band, large view field and large aperture coude three reflection afocal optical system used for detecting long-distance objects within a large scope, and object detection distance and detection probability can be improved. In a structure of the optical system, a main reflecting mirror with a paraboloid and a secondary reflecting mirror with double curved surfaces form a telescope objective system, an object space focal point of a three reflection mirror with double curved surfaces and an image space focal point of a telescope objective coincide, an entrance pupil is positioned on the main reflecting mirror, and a plane scanning mirror is positioned on an exit pupil of the system In the optical structure provided in the invention, design of the large view field and large aperture coude three reflection afocal optical system free from secondary block is realized via small decentration and inclination. Compared with a coaxial system, the coude three reflection afocal optical system is advantageous in that while a similar mechanical structure is kept, secondary blocking caused by three mirrors in a large view filed can be prevented, and the view field can be enlarged; compared with a conventional off-axis system, the coude three reflection afocal optical system is advantaged by compact structure, small size, capability of meeting requirements for system miniaturization and light weight, small introduced decentration and inclination, large amplification factor, and MTF close to a diffraction limit.

Description

technical field [0001] The invention relates to a wide-band, large-field-of-view, large-aperture folding-axis triple-mirror afocal optical system, which is applicable to the front afocal telescopic system of the third-generation forward-looking infrared system. Background technique [0002] Afocal system is also called telephoto system. As an important optical system, it is mainly used in laser beam expander, infrared and forward-looking infrared, telephoto lens and zoom lens. Among them, the forward-looking infrared system consists of a front telescopic afocal system and a subsequent imaging system. As the common aperture part of the multi-channel imaging system, the front telescopic afocal system compresses the entrance pupil, the scanning mechanism is located at the exit pupil, and the reflected collimated beam enters the subsequent imaging system. With the third-generation forward-looking infrared imaging system jointly developed by Raytheon and the Night Vision and Ele...

AI Technical Summary

Problems solved by technology

However, for large-diameter systems, the off-axis distance is large, the magnification is difficult to increase, and the processing cost and difficulty of assembly and adjustment are greatly increased.

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