Gain characteristics and femto-second optical pulse response of 1550 nm-band multi-stacked QD-SOA grown on InP(311)B substrate

In this paper, we demonstrated 155 nm-band multi-stacked QD-SOA grown by the strain-compensation technique on an InP(311)B substrate, and evaluated the fundamental gain characteristics and the femto-second optical pulse response, for the application to ultra-fast all-optical logic gate devices. The device length was 1650 μm, and a maximum gain of 35 dB was obtained under an injection current of 500 mA. We also input two serial femto-second duplicated pulses into the QD-SOA by changing the duration and observed the output auto-correlation waveforms. As a result, an effective carrier transition time was estimated to be about 1 ps.