Abstract

For wind velocity measurements using direct/heterodyne detection Doppler techniques in a LIDAR system a pulsed laser with a single frequency is needed. The standard performance is to seed a high-power pulsed master oscillator with a continuous wave single frequency seed laser. The methods to control the cavity length to match the resonance criteria for the seed wavelength are either based on measurement of the pulse properties like pulse-built-up time as control signal or measurement of the transmitted/reflected cw seed-laser signal like cavity dithering, Pound-Drever-Hall method and ramp-fire method [1]. Either method operates via a servo system that adjusts the cavity length for the next pulse that occurs in the order of 10 to 100 ms later without an exact reliable single frequency operation.

© 2015 IEEE