Direct wave face conversion scanner for direct sight synthetic aperture laser imaging radar emitting light beam

Abstract

The principle of a direct wave face conversion scanner for a direct sight synthetic aperture laser imaging radar emitting light beam is that a Mach-Zehnder polarized interferometer is adopted to divide an incident light beam into two cross-polarization separated space channels, each of the channel is internally provided with a track-along cylindrical mirror needed by phase quadratic term traversing and a track-crossing cylindrical mirror needed by phase line modulating, the track-crossing cylindrical mirror is provided with a scanning driver, and wave face conversion is performed on the light beam by combining the cylindrical mirrors of the two channels to generate two coaxial cross-polarization scanning emitting wave faces which are imaged to a target face by an emitting optical main mirror. The direct wave face conversion scanner for the direct sight synthetic aperture laser imaging radar emitting light beam has the advantages of simple and reliable structure, small size, small transmission loss, vibration resistance, realizing precise phase quadratic term by adopting a high-precision non-spherical optical element, and capability of changing the work mode and the running performance parameters of a radar by adopting the cylindrical mirrors with different focal lengths and different scanning directions without changing the whole structure.

Description

technical field [0001] The invention relates to a laser emission system for direct-looking synthetic aperture laser imaging radar, in particular to a system that directly uses optical elements to perform wavefront conversion and scanning of light beams. It has two structures of double-drive and single-drive scan. The structure of the Del polarization interferometer divides the incident beam into two spatial channels separated by orthogonal polarization. In each channel, the cylindrical mirror required for the quadratic term history of the along-track phase and the modulation of the cross-track phase linear term are placed in each channel. The required cylindrical mirror, the cross-track cylindrical mirror has a scanning driver, and the combination of the two channel cylindrical mirrors transforms the wavefront of the beam to generate two coaxial polarization orthogonal scanning emission wavefronts, which are transmitted through the emission optical primary mirror Imaging direc...

AI Technical Summary

Problems solved by technology

This wave-front transform scanner based on cylindrical mirror space propagation design has the following problems: (1) Due to the use of space diffraction propagation, the wave-front transform scanner of the entire emitted beam is bulky, with large transmission loss, and the vibration of the airborne platform is greatly affected ; (2) Since the quadratic term of the required phase is generated by the spatial diffraction of the cylindrical mirror, the error of the quadratic term of the obtained wavefront is large; (3) Direct-looking synthetic aperture laser with one-dimensional distance resolution / one-dimensional aperture synthesis Imaging radar and two-dimensional aperture synthetic direct-looking synthetic aperture laser imaging radar have different structures of wavefront transformation scanners based on space propagation design and lack of versatility; The phase distribution function of the field, at this time, the optical and mechanical structure of the entire wavefront transformation scanner must be changed, and the applicability is poor

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