5-ps 10-GHz pulse generation from a new ring oscillator with an all-optical semiconductor switch

We observed the spontaneous generation of nearly transform-limited pulses (5 ps, 10 GHz, 1558 nm), for the first time, from a new semiconductor ring oscillator that we had proposed in a previous paper. This oscillator is completely different from conventional mode-locked lasers in that the pulse width is passively determined by a split delay time incorporated in its ring cavity. This is because the ring cavity includes an all-optical SOA-based switch whose switch-window width is determined by the split delay time.