We show that thermally induced birefringence in an electro-optical crystal can play an important role in Q-switched Nd:YAG lasers with a high average power output. A compensation of the thermal effects in both active-element and electro-optical crystals is achieved by employing two identical Pockels cells instead of one, with a π/2 polarization rotator between them in the so-called ring modulator. Experiments that are carried out show that undesirable thermopolarization effects are essentially eliminated by using this new optical configuration. A detailed description in terms of Jones matrices of the properties of the proposed resonator is also included.
© 1993 Optical Society of America
Original Manuscript: September 10, 1990
Published: January 20, 1993
S. Z. Kurtev, O. E. Denchev, and S. D. Savov, "Effects of thermally induced birefringence in high-output-power electro-optically Q-switched Nd:YAG lasers and their compensation," Appl. Opt. 32, 278-285 (1993)