We show by computer simulation that high beam quality can be achieved in high-energy, nanosecond optical parametric oscillators by use of image-rotating resonators. Lateral walk-off between the signal and the idler beams in a nonlinear crystal creates correlations across the beams in the walk off direction, or equivalently, creates a restricted acceptance angle. These correlations can improve the beam quality in the walk-off plane. We show that image rotation or reflection can be used to improve beam quality in both planes. The lateral walk-off can be due to birefringent walk-off in type II mixing or to noncollinear mixing in type I or type II mixing.
© 2001 Optical Society of America
Arlee V. Smith and Mark S. Bowers, "Image-rotating cavity designs for improved beam quality in nanosecond optical parametric oscillators," J. Opt. Soc. Am. B 18, 706-713 (2001)