<title>The design of active laser detection system based on nonlinear optical effect</title>

Abstract

A design is described for photoelectric equipment reconnaissance using an active laser detection system based on the 'cat's eyes' effect of optical windows and the technique of non-linear Optical Phase Conjugation (OPC). With 'cat's eyes' effect, the detection of uncooperative target can be translated into one of a cooperative target, so the ratio of returned laser for remote target can be increased. The receiver used for receiving retro-reflection laser employs a laser amplifier, a Phase Conjugating Mirrors (PCM) based on Stimulated Brillouin scattering (SBS), as it allows for compensation of spatial non-uniformity on the laser pass coming from atmospheric turbulence. The system is thus composed of a laser emitter, a laser receiver and an information processing subsystem. The light reflected by the optical window of target acts as the beacon light. The phase conjugate light which is produced by the laser receiver according to the wavefront aberration of the beacon light is emitted to the target, and reflected by the target to the receiver and information processing subsystem separately. This system is capable of sustaining oscillation between target and laser receiver, locks onto a target and then detects its position and velocity accurately.