POWERFUL SINGLE-MODE Nd LASERS WITH SELF-PHASE-CONJUGATION

摘要

The pulse-periodic Nd: YAG laser with self-pumped phase-conjugate multiloop cavity is developed. A Sagnac interferometer as the laser cavity rear mirror is applied. The parametric feedback is realized by dynamic holographic gratings in the active Nd:YAG rods and LiF:F_2~- passive Q-switcher. It is shown that the additional amplifier and half-wave plate placed in the interferometer can increase significantly the lasing efficiency up to 2 %. Laser operates with 120 W average output power and 6.9 MW peak power at beam divergence 0.5 mrad and spatial brightness 1:10~(14) W/cm~2sr. The similar multiloop laser scheme is experimentally investigated for Nd:YAP laser crystals. To realize the single-mode generation, the additional thermolenses compensation was applied by optimization of distances between active elements, forming telescopic system at powerful pumping. In case of Nd:YAP active rods we get 51 W average output power and 2.8 MW peak power at beam divergence 1.2 mrad.