Single Passband Microwave Photonic Filter With Continuous Wideband Tunability Based on Electro-Optic Phase Modulator and Fabry–Pérot Semiconductor Optical Amplifier

We propose and experimentally demonstrate a microwave photonic filter based on an electro-optic phase modulator (EOPM) and a Fabry-Pérot semiconductor optical amplifier (FP-SOA). A microwave photonic filter with a single passband between 0 and 40 GHz is obtained. In the single passband microwave photonic filter, the microwave subtraction effect is introduced in optical domain to improve the performance. A theoretical model is established to describe the operation principle of the microwave photonic filter, and the predicted results show good agreement with the experimental results. In the experiment, the center frequency and the 3-dB bandwidth are 18.3 GHz and 99.5 MHz, respectively, with the corresponding Q factor of 184, and the rejection ratio and shape factor are 34.3 dB and 5, respectively. The continuous wideband tunability of the microwave photonic filter is also demonstrated by adjusting the bias current of FP-SOA.