Polarization-dependent gain in bismuth-doped phospho- and germanosilicate fiber amplifiers.

Polarization-dependent gain (PDG) effect was studied in a conventional core-pumping configuration of bismuth-doped fiber amplifiers (BDFAs) based on PANDA-type phospho- and germanosilicate core fibers. The PDG value was determined as the gain difference between the orthogonal signal polarizations, which was found to be in range of 2.5-3 dB at total gain of >20 dB in such BDFAs.