HIGH-SPEED OPTICAL TIME-DIVISION DEMULTIPLEXER USING SEMICONDUCTOR OPTICAL AMPLIFIERS

A nonlinear model for the dynamic operation of semiconductor optical amplifiers has been developed using computer simulation techniques. The model is used to investigate the performance of semiconductor optical amplifier serving as an optical gate for a high-speed optical time division demultiplexer. The performance of the amplifier as an optical gate is also shown as a function of the input optical signal levels, frequency and amplitude of the sinusoidal driving signal, and the precise time delay between the input optical signal and the driving electrical signal. The simulation results indicate that maximum demultiplexing speed can be increased from the 6-Gb/s maximum speed achievable using a single amplifier gate, to 10-12 Gb/s by using an optical gate consisting of two cascaded amplifiers. Those satisfactory high speeds demultiplexing performances are also shown to be achievable over a wide range of input signal levels (-20 dB less-than-or-equal-to E(in)/E(sat) less-than-or-equal-to 0 dB), using an optical gate consisting of two cascaded TWSOA's, each with a 2:1 and/or 4:1 selection ratios.