Emitter-receiver laser device and its application with a system of distant detection

摘要

An emitter-receiver laser device with heterodyne detection comprises a laser emitter (1), an optical separating lamina (6), a rotary shutter (11) and an optical system (10), aligned successively on the same axis (2), in order to form a beam of impulses (29) illuminating the target, and on the return axis (13) of the separating lamina (6) it has a crystal (14) which produces frequency shifting of the radiation (reference beam) and which is followed by a photoelectric detector (16) which also receives an echo (30) of the laser impulses returned by the target. The output of detector (16) is amplified by amplifier (22) and passed through an envelope detector (23) and amplifier (24) to undergo a syndronous detection at the modulation low frequency produced by the shutter (11). Parasitic retroreflections of the laser impulses from the optical system (10) do not confuse the detector (16) in this arrangement. IMAGE