Double-film refraction and reflection type co-detector imaging system

Abstract

The invention provides a double-film refraction and reflection type co-detector imaging system, and belongs to the technical field of optics. The system comprises a primary mirror, a secondary mirror, a relay mirror group and a focal plane detector, wherein the primary mirror, the secondary mirror, the relay mirror group and the focal plane detector are placed sharing the same optical axis; the primary mirror and the secondary mirror are of a Cassegrain structure; the primary mirror is provided with a central hole, the secondary mirror is placed in front of the primary mirror, and the relay mirror group and the focal plane detector are placed at the back of the secondary mirror; the secondary mirror is a Mangin mirror, the front surface of the secondary mirror reflects medium wave infrareds and transmits long wave infrareds, and the back surface of the secondary mirror reflects long wave infrareds; arrangement of the two reflecting surfaces of the secondary mirror enables the medium wave infrareds and the long wave infrareds to be the same in optical distance so as to enable the medium wave infrareds and the long wave infrareds to be imaged on the same focal plane under the condition without focusing. The system can achieve two-waveband operation and imaging in a long focal distance and with a large relative aperture, and is compact in structure and little in distortion, a transfer function reaches or is close to a diffraction limit, and cold aperture matching reaches 100%.

Description

technical field [0001] The invention belongs to the field of optical technology, and relates to an infrared mid-wave / long-wave dual-mode catadioptric common-detector imaging system. Background technique [0002] With the development of a new generation of multi-band infrared detector technology, the use of multi-band imaging has become more and more widespread. In order to successfully apply the new generation of detectors, it is necessary to design an optical system capable of multi-band imaging at the same time. [0003] In the field of infrared imaging, the most widely used spectral bands are mid-wave infrared (3μm-5μm) and long-wave infrared (8μm-12μm). These two bands have different advantages and limitations compared to each other. The best way is to use a dual-band infrared detector to combine the above two bands so that their advantages complement each other. [0004] The main problem in the design of dual-band optical systems is that the dispersion characteristics...

AI Technical Summary

Problems solved by technology

Dual-band infrared detectors are generally cooled detectors, so there is a cold stop in the detector. The existence of the cold stop makes the total reflection optical system have to perform secondary imaging to achieve cold stop matching, which makes it impossible to use the most widely used Two-mirror system design (two-reverse Gregorian system can realize secondary imaging, but the imaging performance of off-axis system is poor, so it cannot be applied)

However, when a compact form factor and a large field of view are required, the design challenge of total reflection optical systems increases dramatically

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