Abstract

An Er doped fiber amplifier (EDFA) is drawing much attention as an optical amplifier. For practical use of this amplifiers, laser diode(LD) pumping is the most important requirement. At present, we have two choices of LD wavelength, 0. 98um and 1.48um[1,2]. In the case of pumping by a 0.98um strained quantum well (QW) LD, high efficiency, large unsaturated gain and low noise characteristics are obtained because of large absorption coefficient and complete three level operation. However since the absorption band is extremely narrow in this wavelength range, we must maintain the pumping wavelength within 4nm, Wavelength control leads not only to cost enhancement of the EFDA but also to a hindrance when the EDFA is operated under the automatic gain control (AGC) or automatic level control (ALC).

© 1990 Optical Society of America