Abstract

Recent experiments have proven the feasibility of EDFA’s in long–span optical transmission systems. In several experiments, thousands of kilometers of transmission has been demonstrated, indicating the possibility of trans–oceanic links using this technology [1]. However, some problems related to the polarization of the signal light still remain unsolved. One of them is the change in the optical signal to noise ratio [2, 3] induced by the active polarization hole burning (PHB) which gives rise to at polarization dependent gain (PDG) in the EDFA’s. In reference [4] the PDG is measured to be in the order of 0.1 dB for an individual EDFA at a gain compression level of 3 dB, and both signal and pump state of polarization (SOP) is shown to be important for the PDG level.

© 1994 Optical Society of America