High precision frequency stabilization of an injection seeded Q-switched Nd:YAG ring oscillator thought for LIDAR-applications

Abstract

Frequency stabilized laser sources in the pulsed domain are of interest for a number of applications. The most prominent are probably LIDAR-measurements. Differential absorption LIDAR and Doppler wind LIDAR require frequency stabilities down to the sub-MHz range. The traditional standard method of pulsed frequency stabilization is the pulse build up time method [1]. During the past years other techniques like ramp and fire or dither lock have been applied. Especially the Pound-Drever-Hall (PDH) [2] technique known from cw injection locking offers the chance of high precision stabilization if the Q of the resonator is not too low. This has recently also been demonstrated in the pulsed regime for Nd:YAG oscillators [3]. We applied such a PDH stabilization modified by a sample and hold controller to an injection seeded Nd:YAG ring oscillator (see Fig. 1).