Gain characteristics and femto-second optical pulse response of 1550nm-band QD-SOA for ultra-fast all-optical logic gate devices

We fabricated the QD-SOA, which was composed of 20-layer-stacked InAs quantum dots structure with the strain-compensation technique grown by MBE, and evaluated the fundamental gain characteristics and ultra-fast optical pulse response for all-optical logic gate devices at a wavelength range around 1550nm. For the device length of 1650 μm, the maximum gain of 34.7 dB was obtained for TE mode. And we also measured femto-second optical pulse response by auto-correlation waveforms to observe a slight pulse broadening of about 55 fs.