Multifunctional Microwave Photonic Processor With Sideband-Dependent Filtering and Phase Shifting Based on Broadband Optical Source and Hybrid Spectrum Slicer

Generally, the previously reported microwave photonic processor realizes only one function. Here, a multifunctional microwave photonic processor that can realize reconfigurable filtering and phase shifting simultaneously is proposed and experimentally demonstrated. It is based on broadband optical source sliced by hybrid spectrum slicer (HSS) consisting of an optical spectrum slicer (OSS) followed by an equivalent electrical spectrum slicer (EESS). A Mach-Zehnder interferometer with an optical variable delay line inserted in one arm severs as the OSS, which is used for realizing a conventional filter response. A dual-polarization dual-parallel Mach-Zehnder modulator (DPol-DPMZM) is biased as an EESS, which is utilized to realize phase-tunable sideband-dependent filter response with the upper DPMZM generating different modulated sideband and the lower DPMZM biased for generating a phase-tunable optical carrier. The passband of the conventional filter response can be arbitrarily shifted after cascading the EESS. The dynamic range is increased due to the carrier-suppressed modulation, and the dispersion-induced power fading can be eliminated for the carrier-suppressed single-sideband modulation and can be alleviated or even fully eliminated for the carrier-suppressed double-sideband modulation. Theoretical analysis is presented and demonstrated by the simulation and the proof-of-concept experiment. The single-passband, dual-passband and triple-passband filters are experimentally demonstrated when selecting different modulated sidebands. The phase shifting with a tunable range from –180° to 180° is achieved, and the dynamic range is improved by 6 dB, compared to the conventional scheme. The simulated results and the experimental results are agreed with very well. This technique has an important application in microwave photonic phased array antenna.