Spectral consequences that result from using birefringent media with broadband gain inside of laser cavities containing polarizing elements are described. We show that the laser intensity is modulated as a function of the output frequency unless the cavity elements are carefully aligned so that their polarization axis coincides with a principal optical axis of the gain medium. Analysis of the tuning characteristics of a birefringent polarizationdependent gain medium is exploited to provide a simple method for line narrowing the laser output. By introduction of an intracavity birefringent compensator the narrow-band output can be continuously tuned. Experimental results for alexandrite lasers are presented.
© 1989 Optical Society of America
J. S. Krasinski, Y. B. Band, T. Chin, D. F. Heller, R. C. Morris, and P. A. Papanestor, "Birefringence of solid-state laser media: broadband tuning discontinuities and application to laser line narrowing," Opt. Lett. 14, 393-395 (1989)