Tunable Single-Notch Microwave Photonic Filter Based on Nonsliced ASE Source

We propose a novel single-notch microwave photonic filter (MPF) using a nonsliced amplified spontaneous emission (ASE) source and a laser diode (LD). The nonsliced ASE is used for implementation of a phase tunable bandpass MPF, where the participation of an LD enables the simultaneous realization of an allpass MPF, without adding more devices into the system. By destructive interfering between the bandpass MPF and the allpass MPF, a single-notch MPF can be achieved with tunable center frequency. Compared with previous approach based on ASE source, the proposed approach has a broader tunable frequency range and a much simpler configuration since it is free from both the wavelength-division-multiplexer (WDM) and polarization processing. The proposed method is theoretically analyzed and experimentally demonstrated.