THE EFFECT of BIREFRINGENCE on POLARIZATION HOLE BURNING in ERBIUM DOPED FIBER AMPLIFIERS.

Polarization hole burning, PHB, has been observed in erbium doped fiber amplifiers[1]. PHB is an anisotropic saturation created when a polarized saturating signal is launched into the erbium doped fiber. A corresponding anisotropic gain is also created. The gain, measured with a weak probe, is found to be larger for a probe polarized orthogonal to the saturating signal compared to a probe polarized parallel to the saturating signal. The effect is typically expressed as the gain difference, δG, (in dB) for the two probe polarizations.