We have observed, for the first time to our knowledge, residual stress-induced birefringent dual-polarization modes in a diode-pumped, single-frequency, microchip cw 2.0914-μm Ho,Tm:YAG laser. The two orthogonally polarized modes were separated in frequency by approximately 12 MHz and, when photodetected, produced a 12-MHz self-heterodyne beat signal. The self-heterodyne signal could be eliminated by an external λ/4 plate and a polarizer to filter out one of the modes, but this required regulation of the pump laser power to better than 1%. These results have important implications for use of the microchip Ho,Tm:YAG laser in a heterodyne detection coherent lidar.
© 1994 Optical Society of AmericaFull Article | PDF Article
Adelbert Owyoung and Peter Esherick
Opt. Lett. 12(12) 999-1001 (1987)
J. J. Zayhowski and A. Mooradian
Opt. Lett. 14(12) 618-620 (1989)
Christian Pedersen, Peter Lichtenberg Hansen, Preben Buchhave, and Torben Skettrup
Appl. Opt. 36(27) 6780-6787 (1997)