Power scaling of continuous-wave adaptive gain-grating laser resonators

We demonstrate a power-scaling strategy in a continuous-wave adaptive phase-conjugate oscillator power amplifier (PCO-PA) system that actively corrects, via phase-conjugation, for thermally induced phase-distortions introduced by a power-amplifier (PA) placed in the output arm of the phase conjugate oscillator (PCO). Phase-conjugation is achieved by saturable gain four-wave mixing in a PCO Nd:YVO4 amplifier. Single-longitudinal mode phase-conjugate (PC) outputs of almost 11.5 W with an M-x(2) = 1.4. M-y(2) = 1.2 have so far been achieved with a PCO operating at 6 W PC output, a power gain of two through the PA. The saturable gain four-wave mixing that takes place in the PCO-PA system has been modelled and the results can be used to predict how best to proceed with further increasing the PC output power from such a system. (C) 2002 Published by Elsevier Science B.V.