Microwave Photonic Bandpass Filter Based on Carrier-Suppressed Single Sideband Injected Distributed Feedback Laser

A novel microwave photonic filter (MPF) based on carrier-suppressed single sideband (CS-SSB) injected distributed feedback (DFB) laser is proposed. The proposed MPF system exploits the frequency selective gain feature of optical injected DFB lasers, which can be tuned by adjusting the optical injection parameters or the working conditions of the laser. Therefore, the proposed MPF system can be tunable. The proposed system is verified by a proof-of-concept experiment, and the results show that the passband of the proposed MPF can be tuned by tuning the injection ratio and bias current of the slave laser, where the tuning range of 9–39 GHz is realized. At the same time, the out-of-band rejection of the proposed MPF can reach to 32 dB. Moreover, a dual-passband MPF response is also realized by the proposed system with a couple of master lasers, and the two passbands can be tuned independently from 10 to 39 GHz.