Microwave photonic filter with a continuously tunable central frequency using an SOI high- Q microdisk resonator

Utilizing a high- Q microdisk resonator (MDR) on a single silicon-on-insulator (SOI) chip, a compact microwave photonic filter (MPF) with a continuously tunable central frequency is proposed and experimentally demonstrated. Assisted by the optical single side-band (OSSB) modulation, the optical frequency response of the MDR is mapped to the microwave frequency response to form an MPF with a continuously tunable central frequency and a narrow 3-dB bandwidth. In the experiment, using an MDR with a compact size of 20 × 20 μm 2 and a high Q factor of 1.07 × 10 5 , we obtain a compact MPF with a high rejection ratio of about 40 dB, a 3-dB bandwidth of about 2 GHz, and a frequency tuning range larger than 12 GHz. Our approach may allow the implementation of very compact, low-cost, low-consumption, and integrated notch MPF in a silicon chip.