Long-range active laser detection system based on cat’s eye effect

Abstract

In order to enhance the detection capability of “cat’s eye” effect existing in the photoelectronic equipment at long-range, we develop a laser active detection system in this paper. The parameters of laser transmitter and imaging system are well-designed based on the requirement of long-range active detection. The laser light is produced by a high energy pulsed laser at 532 nm, assembled with a beam expander which can achieve a tunable laser divergence angle from 0.03° to 5°, and the reflected light can be detected by a CMOS assembled with an long-focal-length optical lens. An experimental demonstration system is build up according to the system design, which can successfully detect a camera (Aperture-50 mm) at a detection range of 5.7 km, with no extra sophisticated signal processing schemes required. An evident “cat’s eye” target can be observed in the raw image from the digital camera (exposure time-3 ms) when the laser divergence angle is 3°, whose intensity is more than 3 times of the background. The results indicate that this work meets the demand of long-range laser active detection based on the “cat’s eye” effect.