Abstract

Adaptive optics and phase-conjugate-mirrors are usually treated as single element optics. Superior performance in the presence of nonreciprocal aberrations can be achieved using compound elements. In this work it is shown that relay imaging between the nonreciprocal aberrator (thermally stressed laser rod= thick birefringent lens) and the retroreflecting I phase-conjugating element results in much better retracing of the laser beam. We applied these techniques to flashlamp pumped Nd:Cr:GSGG oscillators and show that systematic correction of thermal focusing and astigmatism requires three sets of elements which, when dynamically corrected, allows high beam quality operation over very broad average pump power ranges. It has not yet been found necessary to correct for thermo-optically induced spherical aberration.

© 2000 Optical Society of America