A four-arm grazing-incidence cavity (GIC) is demonstrated. It ensures stable single-mode operation in a pulsed laser system by interferometrically enhancing mode selection; the corresponding standard GIC operates on five modes. We show that the four-arm GIC gives the best overall performance in terms of mode selectivity and threshold when compared with the standard GIC or with three-arm GIC's. In addition, an analysis of the interference effect is detailed that allows the four-arm GIC to be optimized for mode selection. Threshold gain and cavity losses are calculated, and the predicted mode spacing and complex reflectance are experimentally verified.
© 1998 Optical Society of America
(140.3410) Lasers and laser optics : Laser resonators
(140.3540) Lasers and laser optics : Lasers, Q-switched
(140.3570) Lasers and laser optics : Lasers, single-mode
(140.3600) Lasers and laser optics : Lasers, tunable
D. J. Binks, D. K. Ko, L. A. W. Gloster, and T. A. King, "Laser mode selection in multiarm grazing-incidence cavities," J. Opt. Soc. Am. B 15, 2395-2403 (1998)