m-z type electro-optical scanning direct-looking synthetic aperture laser imaging radar launch system

Abstract

An M-Z (Mach-Zehnder) electrooptical-scanning orthophoria synthetic aperture laser imaging radar transmitting system comprises a laser, a half wave plate, an aperture diaphragm, a first polarization beam splitter, a first reflection plate, a first electrooptical scanner, a first cylindrical mirror, a second reflection plate, a second electrooptical scanner, a second cylindrical mirror, a second polarization beam splitter, a transmitter-telescope primary mirror, a high-voltage power source and a control computer, wherein the first polarization beam splitter, the second polarization beam splitter, the first reflection plate and the second reflection plate are mutually parallelly arranged to form a Mach-Zehnder structure. The laser imaging radar transmitting system is capable of realizing parabolic equipotential line difference of two polarization orthogonal light beams at a far-field target, is used for scanning targets, simple in structure, free of mechanical scanning, small in size, light in weight, and particularly suitable for onboard or satellite-borne high-speed operating carrying platforms, and response speed for electrooptical phase modulation wave surfaces is fast and up to nanosecond level.

Description

technical field [0001] The invention relates to laser radar, in particular to a Mach-Zehnder type (abbreviated as M-Z type) electro-optic scanning direct-looking synthetic aperture laser imaging radar transmitting system. Background technique [0002] The principle of synthetic aperture laser imaging radar is taken from the principle of synthetic aperture radar in the radio frequency field, and it is the only optical imaging observation method that can obtain centimeter-level imaging resolution at long distances. Traditional synthetic aperture laser imaging radars transmit light waves and receive data under the condition of side view, and adopt optical heterodyne reception, which is greatly affected by atmospheric disturbance, vibration of moving platform, target speckle and phase change of the laser radar system itself. , it also requires the initial phase of the beat signal to be strictly synchronized and a long-distance delay is required to control the phase change, which...

AI Technical Summary

Problems solved by technology

However, the launch system proposed by the direct-looking synthetic aperture lidar uses two beam deflectors to scan the two beams in opposite directions so that the light field distribution of the inner launch field is in the form of a quadratic spatial phase. At this time, only precise synchronization is required. In order to obtain the linear phase modulation in the cross-track direction, it is difficult and complicated to make the precise synchronization of the two beams scanning oppositely. At the same time, the beam deflector generally uses mechanical deflection scanning, which has slow response speed and large moment of inertia, which is not conducive Loading and other high-speed carrying applications on the platform

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