High-Speed Switchable Dual-Passband Microwave Photonic Filter With Dual-Beam Injection in an SMFP-LD

In this paper, a high-speed switchable dual-passband microwave photonic filter (MPF) using a single mode Fabry-Perot laser diode (SMFP-LD) is proposed and experimentally demonstrated. Benefiting from the wavelength selective amplification in the SMFP-LD, the +1
^st
sideband of two external beams injected after phase modulation can be amplified in the gain spectrum of the SMFP-LD. Hence, an MPF with two tunable passbands is generated. The switching of the generated passbands is obtained through the switching signal of 1 Gbps applied to the modulator, which controls the power of one of the external beams. By properly setting the external beams’ injection parameters, the passbands of MPF can switch from single passband to no passband, single passband to dual passband, and one passband to another passband. In this experiment, the maximum center frequency and tuning range of the passbands is 45.0 GHz and 35.0 GHz, respectively. The out-of-band rejection ratio and 3 dB bandwidth of the proposed filter are 29.62 dB and 83 MHz, respectively.