Polarization spectroscopy applied to the frequency stabilization of rare-earth-doped fiber lasers: a numerical and experimental demonstration

摘要

The frequency response of a unidirectional ring laser containing a linear polarizer and a weakly birefringent etalon is analyzed numerically. The data obtained indicate that by sensing the changes in the polarization state of the light that is coupled from the etalon, a suitable error signal can be derived that can be used to prevent longitudinal mode hops. This idea is verified experimentally by configuration of an erbium ring fiber laser with a nonplanar 3 x 3 fused-fiber coupler to form the intracavity etalon. When the longitudinal mode hops are inhibited and the oscillating frequency of the fiber laser is locked to a reference confocal etalon, the resulting radiation has a linewidth of 14 kHz with an associated rms frequency jitter of 2 kHz. (C) 1997 Optical Society of America.