Continuously tunable microwave phase shifter based on a tilted fiber Bragg grating

A continuously tunable microwave phase shifter implemented using a tilted fiber Bragg grating (TFBG) written in an erbium/ytterbium (Er/Yb) co-doped fiber is proposed and experimentally demonstrated. By optically pumping the TFBG, the magnitude and phase responses of the cladding mode resonances are changed, which is used to introduce a tunable phase shift to the optical carrier of a single-sideband with carrier (SSB+C) modulated signal. A tunable phase shifter with a tunable phase of 280⁰ at a microwave frequency tunable from 24 to 36 GHz is experimentally achieved.