Diffraction losses for symmetrically perturbed curved reflectors in open resonators.

The diffraction power losses for slightly tilted (perturbed) open resonator reflectors with both circular and rectangular apertures are computed for several tilt angles and reflector radii of curvature. Computational results indicate that the power losses increase monotonically with increasing tilt angle for stable systems, while for unstable systems the power losses are hardly affected by the tilt angle. At a given tilt angle, the perturbation generated power losses are negligible for the confocal case but become significant as the geometry of the system approaches that of the concentric or plane-parallel resonator and fluctuate about the unperturbed values for an unstable geometry. This last result may have applications for unstable laser design.