Abstract

Linear folded cavities are widely used as they meet the requirements of a small spot size in the short arm needed for high gain, and a collimated beam in the long arm, allowing the insertion of different optical elements for wavelength selection or Q-switching. The spherical mirror used with an oblique angle of incidence introduces astigmatism, but as explained in the well-known paper of Kogelnik and al. [1], these distortions can be balanced by the astigmatism of a Brewster angle element Such a cavity should be designed not only for astigmatism compensation but also for minimal sensitivity to lengths fluctuations [2], that could generate output power variations.

© 1996 IEEE