Simulation of 12.5 Gb/s lightwave optical time-division multiplexer using semiconductor optical amplifiers as external modulators

Using computer simulation techniques, a nonlinear model is developed for the use of traveling-wave semiconductor optical amplifiers as external modulators for multigigabit per second optical time-division multiplexed (OTDM) lightwave systems. The simulation results indicate that the modulation performance is sensitive to the precise time delay between the incident optical pulse and the electrical injection current pulse required to drive the traveling-wave semiconductor optical amplifier (TWSOA) external modulator. It is found that satisfactory modulation performance is obtained when the peak of the input optical pulse p/sub in/(t) coincides with the trailing edge of the injection current pulse I(t). The simulation results then indicate that, under this condition, adequate modulation performance at 2.5 Gb/s per channel, over a practically useful range of input signals, is possible provided that -10 dB>