Abstract

Laser-gain-controlled erbium-doped fiber amplifiers (EDFA), in which automatic gain control is achieved by introducing lasing at a particular wavelength in the optical amplifiers,^1,4 are very attractive for their application in multiwavelength optical networks. A number of experimental demonstrations using this automatic gain control scheme were reported.^1,4 This report presents for the first time a comprehensive theoretical study on the laser-controlled EDFAs. Explicit analytical expressions are derived for the calculation of amplifier gain and noise spectra, critical input signal power, and optimum amplifier length without resorting to any numerical methods of analysis. Based on these expressions, the issues of amplifier optimization for the critical input signal power maximization and gain spectral flattening are addressed.

© 1996 Optical Society of America