Stability of polarized modes in a quasi-isotropic laser
Abstract
The polarization states of quasi-isotropic lasers are highly sensitive to residual cavity anisotropies and to weak (parasitic) anisotropic feedback. Internal anisotropies are usually constant, whereas the effective mirror anisotropy produced by feedback is strongly frequency (phase) dependent. A model for such a laser is developed, and analytic steady-state solutions are obtained for the case when both anisotropies are parallel. The linear stability analysis is also analytic. For the 3.39-micron He-Ne laser, the theory explains the previously observed variations with frequency of the intensity of the laser, the regions of monostable linear polarization, and in the bistable region the inverse dependence of the width of the hysteresis loop on the low-signal net gain. In contrast to Lamb's (964) theory, the calculations show that the polarization flip arises from an instability in the relative phase between the vector components of a mode.
- Publication:
-
Journal of the Optical Society of America B Optical Physics
- Pub Date:
- December 1989
- DOI:
- 10.1364/JOSAB.6.002355
- Bibcode:
- 1989JOSAB...6.2355M
- Keywords:
-
- Helium-Neon Lasers;
- Laser Stability;
- Linear Polarization;
- Optical Bistability;
- Optical Polarization;
- Polarized Light;
- Anisotropy;
- Feedback;
- Infrared Lasers;
- Laser Modes;
- Lasers and Masers