Polarization-Insensitive Clock Recovery Operation in a Monolithic Passively Mode-Locked Distributed-Bragg-Reflector Laser Integrated With a Tensile-Strained Multiple-Quantum-Well Saturable Absorber

A 40-GHz monolithic mode-locked laser diode integrated with a tensile-strained multiple-quantum-well saturable absorber was developed for the purpose of polarization-insensitive all-optical clock recovery in a single chip of a semiconductor device. Clock recovery with small polarization sensitivity less than 0.2 dB was successfully achieved. We also demonstrated a stable clock recovery from polarization-scrambled data signals.