All-optical clock division with mode-locked figure-eight laser based on the slow carrier recovery rate in semiconductor optical amplifier

With a mode-locked figure-eight laser, we demonstrate the clock division operation using a semiconductor optical amplifier (SOA) with a slow carrier recovery rate. We show stable clock division at 2.5 GHz and two output states at half the repetition rate of the 10 GHz input pulses. The forming pulses in the laser cavity will interact with each other at the onset of mode locking when the SOA in the laser has a relatively slow carrier recovery rate. A numerical model of the laser is built to simulate the generation of clock division.