Widely tunable single bandpass microwave photonic filter based on dual-fiber stimulated Brillouin scattering

A new technique to achieve a single bandpass microwave photonic filter (MPF) with wide tunability based on stimulated Brillouin scattering is proposed. The MPF cascades the Brillouin frequency shifter and amplification based on a dual-fiber structure. The experimental results present a single bandpass MPF located at 21.4 GHz with a 3-dB bandwidth of 38 MHz and an out-of-band rejection ratio over 30 dB. The proposed single bandpass MPF also successfully demonstrates a wide-band tuning over 40 GHz, which is achieved by employing a frequency shifter based on carrier suppressed single-sideband modulation scheme in the structure.