Amplification and shaping of picosecond gigabit optical pulse by using traveling-wave semiconductor optical amplifier

The amplification of picosecond optical pulse train with Gigabit repetition rate by using a traveling-wave semiconductor optical amplifier (TWSOA) is studies. The effect of driven current and operating temperature on the performance of TWSOA in amplification of picosecond negatively chirped optical pulses from gain-switched laser diode (GSLD) are characterized. The maximum output peak power and gain of the TWSOA operated at pulse mode are determined. The distortion in trailing edge of pulse shape is significant under the TWSOA operating at higher driven levels, such a nonlinear phenomenon inherent with the TWSOA leads to the broadening of pulsewidth and the saturation of peak power and gain of optical pulses. The optimized operating parameters such as the driven levels and temperatures of TWSOA and GSLD for generating and amplifying shorter optical pulse with higher gain are obtained, which are at below threshold and lower than room temperature conditions. The shortest pulse generated from GSLD and amplified by the TWSOA are 13 ps and 17 ps, respectively.