A novel method of a gain-enhanced long-wavelength band (L-band) erbium-dope
d fiber amplifier is presented utilizing a gain-clamped amplifier based on
a ring-laser feedback. The laser output is used as a seed signal into a sec
ond-stage amplifier, and has improved the L-band gain for higher dense wave
length-division multiplexed channels. (C) 2001 John Wiley & Sons, Inc.