The performance of a traveling-wave-type semiconductor laser amplifier as a booster in multiwavelength simultaneous amplification

In this study, the theoretical worst and the average interchannel crosstalk are shown as a function of normalized input power. The validity of normalization by saturation input power is confirmed by experimental data. This normalized input power must be set below -20 and -10 dB for multiwavelength numbers of 20 and 4, respectively, to attain an average interchannel crosstalk of under -10 dB. The optical loss, including interchannel crosstalk, that can be compensated by a traveling-wave-type semiconductor laser amplifier (TWA) is analyzed. The experimental results indicate that the compensable optical loss could be evaluated by using the average interchannel crosstalk in multiwavelength transmission system design. Applying a TWA as a preamplifier is more effective in systems that include excess optical loss in the receiver