Abstract

The excellent performance of the Er-doped fiber amplifiers has been demonstrated in diverse fields so far. Reliability and compactness of the EDF, however, are still key issues for practical applications of EDFAs. To make a compact EDF coil, it is necessary to reduce the EDF length and the coil diameter. Reduction of the EDF length is achieved by high Er-concentration. We have tried a high temperature plasma for high concentration Er-doping for the first time as far as we know. Small diameter coil winding degrades the mechanical reliability of the EDF. We have applied the hermetic carbon coating [1] on the EDF and additional metal coating on the carbon layer [2].

© 1992 Optical Society of America