Photonic microwave phase shifter based on dual-sideband phase-control technique

An all-optical photonic microwave phase shifter that can realize a continuous 0 degrees-360 degrees phase shift is presented. The phase-shifting operation is implemented by controlling the phase of the two RF phase-modulation sidebands while keeping the optical carrier phase fixed. The use of two RF modulation sidebands, instead of a single sideband used in most conventional phase shifters, has the advantage of high-output RF signal power, and consequently high signal-to-noise ratio performance. Experimental results demonstrate the full -180 degrees to +180 degrees phase shift over a wide microwave frequency range from 11 to 26.5 GHz, and 14 dB increase in the output RF signal power compared to a conventional phase shifter. (C) 2015 Optical Society of America