Application of high power solid state lasers to remote sensing

The paper investigates the applicability of a laser radar system employing high-power solid-state lasers to the remote sensing of oil pollution. The system consists of second and fourth harmonic generators of a repetitively Q-switched Nd-3+:YAG laser that generate laser pulses used for excitation, a Cassegrainian telescope, a gated optical multichannel analyzer, a system controller, and a data processor. The theoretical performance of a laser radar with a continuous-wave laser or a pulsed laser for the detection of Raman backscattering of oil is discussed, and several methods for producing high power laser pulses are described, including the generation of tunable ultraviolet radiation due to the mixing of ruby and dye laser beams. Results of a field experiment indicate that the radar system is capable of remotely detecting oil pollutants present in sea water. The operation of the system in the synchronous gated detection mode with pulsed light sources, decreases the noise from the background light to allow operation in the daytime.