980-nm pump-band wavelengths for long-wavelength-band erbium-doped fiber amplifiers

The impact of pump wavelength and input signal power on the output signal and backward spontaneous emission noise power of L-band erbium-doped fiber amplifiers is examined. It is shown experimentally that tuning the pump wavelength /spl plusmn/30-nm away from the 980-nm absorption peak provides 3-5-dB improvement in pump-to-signal conversion.