A Variable-Gain Optical Amplifier for Metro WDM Networks With Mixed Span Losses: A Gain-Clamped Semiconductor Optical Amplifier Combined With a Raman Fiber Amplifier

摘要

We propose a variable-gain optical amplifier that exhibits excellent performance in metro wavelength-division-multiplexing networks containing mixed span losses. The amplifier consists of a variable-gain Raman fiber amplifier and a gain-clamped semiconductor optical amplifier. Each span of different loss is exactly compensated by adjusting the pump power of a Raman laser diode to have the maximum optical signal-to-noise ratio. Sixteen channels of 10-Gb/s signals were successfully transmitted over 170 km of mixed span losses (total, 87 dB) under dynamic additions/removals situations.