Polarization effects in a high-birefringence elliptical fiber laser with a Bragg grating in a low-birefringence fiber

The polarization characteristics of a fiber laser cavity that combines a high-birefringence Er(3+)-doped elliptical core fiber with a Bragg grating fabricated in a low-birefringence (Low-Bi) fiber are studied. It is shown that, by use of an adequate length of Low-Bi fiber and an intracavity polarization controller, the dependence of the fiber laser's state of polarization on the pump's state of polarization can be altered. This fiber laser cavity design allows for the realization of a double-frequency, orthogonally polarized single-mode fiber laser source insensitive to the polarization parameters of the pump source.