Multifunctional microwave photonic processor based on Brillouin selective sideband amplification and carrier phase shift

A multifunctional microwave photonic signal processor based on Brillouin selective sideband amplification and carrier phase shift is proposed and experimentally demonstrated. Using the stimulated Brillouin scattering (SBS) to selectively amplify a carrier-suppressed single-sideband (CS-SSB) signal generated in one dual-parallel Mach-Zehnder modulator (<i>X</i>-DPMZM). The phase of the optical carrier is shifted in the other DPMZM (<i>Y</i>-DPMZM). The amplified CS-SSB signal in joint with the phase-tunable optical carrier can realize the filtering and phase shifting simultaneously. The suppression ratio exceeding 32 dB and a 3 dB bandwidth below 90.5 MHz are achieved. The central frequency of the filter can be finely tuned through an electro-optic frequency shifter, and the frequency tuning range can be extended up to 20 GHz by alternately using the upper sideband and lower sideband as the pump light, breaking through the bandwidth limitation of the processor. At the same time, full-range (0°-360°) phase shifting for the filtered microwave signal is realized through adjusting the phase of the optical carrier, independent of the filtering function. In addition, the third-order intermodulation distortion (IMD3) is suppressed by 10.8 dB compared to the traditional one.