Monolithically Integrated Microwave Frequency Synthesizer on InP Generic Foundry Platform

A photonic integrated circuit for microwave generation is proposed and experimentally validated. On the microchip, two tunable monochromatic lasers spectrally separated by 0-10.7 nm are monolithically integrated with one high-speed photodiode in heterodyne configuration for enabling continuous RF synthesis from 2 to 42 GHz. Under free-running operation, the two lasers with 20-40 MHz optical linewidth produce RF beat note with ~90 MHz electrical linewidth at the on-chip photodiode. This is the first demonstration of such a fully integrated microwave photonic generator developed within an open-access generic foundry platform.