Heterogenous integrated silicon-photonic module for producing widely tunable narrow linewidth RF

Generating RF signals over the entire spectrum, from hundreds of MHz into the hundreds of GHz, has previously required the use of special oscillators designed only for specific bands of operation within that spectrum. An optoelectronic system based on side-band-injection-locked lasers is capable of generating RF frequencies tunable over a span of more than 7 octaves with extremely low phase noise. [1] Here we present the results of our efforts to develop a heterogeneously integrated version of this system based on a silicon-photonic integrated circuit coupled to III-V semiconductor gain chips. Towards that effort, we have successfully demonstrated an integrated module and shown tunable RF generation with a ~1 Hz linewidth.