A Narrow-Passband and Frequency-Tunable Microwave Photonic Filter Based on Phase-Modulation to Intensity-Modulation Conversion Using a Phase-Shifted Fiber Bragg Grating
A novel approach to implementing a narrow-passband and frequency-tunable Microwave Photonic Filter (MPF) based on phase-modulation to intensity-modulation conversion in a Phase-Shifted Fiber Bragg Grating (PS-FBG) is proposed and experimentally demonstrated. In the proposed MPF, a phase-modulated signal is sent to a PS-FBG. If one of the sidebands falls in the notch of the PS-FBG, the phase-modulated signal is converted to an intensity-modulated signal. Due to the ultra-narrow notch of the PS-FBG, a microwave filter with an ultra-narrow passband is realized. The tunability of the microwave filter is achieved by tuning the wavelength of the optical carrier.