Tunable optical microwave bandpass filter with negative coefficients using an optical phase modulator and chirped fiber Bragg gratings

Abstract

A novel approach to implementing a tunable optical microwave bandpass filter with positive and negative coefficients based on an optical phase modulator and chirped fiber Bragg gratings is proposed and experimentally demonstrated. The positive and negative coefficients are generated through optical phase-modulation to intensity-modulation (PM-IM) conversion using linearly chirped fiber Bragg gratings (LCFBGs) with opposite dispersions. By changing the wavelength of the optical carrier within the chirp range of the LCFBGs, the tunability of the filter response is realized. A two-tap tunable microwave bandpass filter is experimentally demonstrated.