Single-mode Nd:YAG laser with a self-pumped phase-conjugate loop cavity

Abstract

A repetitively pulsed Nd:YAG laser with a self-pumped phase-conjugate loop cavity is proposed. A Sagnac interferometer is used as the end reflector. Parametric feed-back is provided by a dynamic holographic gratings in the active elements and a passive LiF:F2− laser Q-switch. It is shown that an additional amplifier and a half-wave plate inside the interferometer can increase significantly the laser efficiency. An average radiation power of 120 W, a peak power of a single pulse of 6.9 MW, an experimentally achieved laser efficiency of 2%, an angular divergence of 0.5 mrad, and a spatial brightness of 1014 W cm-2 sr-1 are reported.