Silicon nitride waveguides for nonlinear optics and frequency comb generation

Optical frequency comb generation has attracted significant interest, particularly for applications in spectroscopy, precision frequency metrology, metrology and optical clocks. Recently, high-quality-factor optical microcavities have shown enormous potential as a platform for efficient nonlinear optical processes. Here we describe recent results results on the use of the silicon-based platform for generating high-precision frequency combs via the process of cascaded parametric four-wave mixing. We demonstrate comb generation that can span more than an octave which represents a significant step towards a stabilized, integrated frequency comb source.