Phase-tunable Microwave Photonic Filter Based on DPol-DPMZM and Microfiber Ring Resonator

A phase-tunable microwave photonic filter is proposed and experimentally demonstrated. The filter is based on a dual-polarization dual-parallel Mach-Zehnder modulator (DPol-DPMZM) and a microfiber ring resonator. The X-DPMZM is properly biased to serve as a carrier-suppressed single sideband (CS-SSB) modulator driven by the RF signal, while the Y-DPMZM is properly biased to sever as an optical phase shifter. The CS-SSB signal and the phase tunable optical carrier are polarization multiplexed and converted into a linear polarization signal by a polarizer, and then sent into a dispersion component. After photodetection, a phase-tunable single-passband filter is obtained. A proof-of-concept experiment is carried out, and the filtered microwave signals can be phase shifted continuously within 360° phase range.