High-Quality Microwave Signal Generation With a Photonic Integrated Asymmetric Mode-Locked Laser

In this work we report an asymmetric mode-locked photonic integrated circuit (ML-PIC) with a 33 GHz fundamental repetition rate (RR) frequency. The device has been fabricated in an Indium Phosphide (InP) photonic integrated Multi-Project Wafer (MPW) run. The design in an on-chip mode locked laser diode using a pair of on-chip reflectors, two semiconductor optical amplifier sections and one saturable absorber section, asymmetrically located with respect to the reflectors. The ML-PIC pulses are generated at the 33GHz fundamental frequency exhibiting a 3dB-linewidth around 417 kHz with a drift around 1 MHz measured over 5 minutes in passive operation regime.