Abstract

Previous calculations of the stability of the polarization modes of lasers, including their stability, bistability and curious catastrophes^1,2 have invoked the mean field approximation. Since the cavity anisotropies and losses are approximated by distributed quantities, the polarization of the laser is the same throughout the cavity. In general then, one expects such an approximation to be valid only for cavities with small anisotropies. Such cavities are appropriately described as quasi–isotropic. We have succeeded in breaking this mean field approximation by propagating a plane wave around a linear cavity with strong optical anisotropies and a saturable gain medium. The calculations allow for the modification, of the saturation induced anisotropy, due to distinct states of polarization for the forward and backward propagating fields. Results are presented both for strongly anisotropic cavities and for quasi-isotropic cavities where mean field and non mean field calculations may be compared. This work was supported by the Natural Sciences and Engineering Research Council of Canada and the Province of Ontario through the Ontario Laser and Lightwave Research Centre.

© 1993 Optical Society of America