Programmable Single-Bandpass Photonic RF Filter Based on Kerr Comb from a Microring

Microresonators with a high Kerr nonlinearity show great potential to generate optical frequency combs with ultrabroad spectra, high repetition rate, and high coherence between comb lines. The compact size and possibility of chip-level integration make the Kerr combs attractive for many applications, especially including photonic radiofrequency (RF) filters. In this paper we report the first demonstration of a programmable photonic RF filter based on the Kerr comb from a silicon nitride microring. A novel scheme enabled by the large frequency spacing of the Kerr comb is introduced in order to suppress unwanted RF passbands including the image and periodic passbands. As a result, a single passband is achieved. To the best of our knowledge, this is the first demonstration of a single-bandpass photonic RF filter employing a discrete-wavelength comb source.