2 mu m coherent laser wind measurement radar off-axis Cassegrain optical antenna system

Abstract

The invention discloses a 2 mu m coherent laser wind measurement radar off-axis Cassegrain optical antenna system. The off-axis Cassegrain optical antenna system is an off-axis Cassegrain double reflection optical antenna system, utilizes a quadric surface to eliminate various junior astigmations and is composed of an optical antenna primary mirror, an optical antenna secondary mirror, a beam pre-expanding system ocular lens and a beam pre-expanding system objective lens. The system can successfully makes up the defects of a general optical antenna system, such as small caliber, large optical energy loss, too large aberration, small view field, large volume, high cost, poor image quality, center sheltering and the like. The designed off-axis Cassegrain optical antenna system has the advantages of good image quality, short lens barrel and no center sheltering, and the focus can be behind the primary mirror, thus facilitating an infrared detector to be placed at the position of the focus. The optical antenna system has very high practical value in the laser radar field.

Description

technical field [0001] The invention relates to a 2 μm coherent laser wind measuring radar optical antenna system, in particular to a 2 μm coherent laser wind measuring radar off-axis Cassegrain optical antenna system with combined transceiver. Background technique [0002] The optical antenna is one of the key systems in the laser wind radar system. It is not only an effective medium for transmitting and receiving the beam, but also has a great influence on the performance of the system. [0003] The optical system is an essential part of the entire laser radar system. The optical system of the laser radar is used to complete the transmission, reception and coherent mixing of the signal beam with the local oscillator beam. The optical antenna system of lidar mainly includes two parts, the transmitting optical system and the receiving optical system. The transmitting optical system is composed of a laser, a beam expander, and a telescope; the receiving optical system is com...

AI Technical Summary

Problems solved by technology

Compared with the Karl's system, the disadvantage of the Grignard system is that its length is longer. If both sides of the Grignard system use ellipsoidal surfaces, the system can have neither spherical aberration nor coma

[0011] An obvious disadvantage of the coaxial double reflection system is that the secondary mirror blocks a part of the beam at the center of the system, and as the field of view and relative aperture become larger, the image quality deteriorates rapidly

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