Phase-shifted Brillouin dynamic gratings using single pump phase-modulation: proof of concept.

ABSTRACT

Two novel phase-shifted Brillouin dynamic gratings (PS-BDGs) are proposed using single pump phase-modulation (SPPM) in a polarization maintaining fiber (PMF) for the first time to our knowledge. Firstly, based on the stimulated Brillouin scattering (SBS), a transient PS-BDG with a 3-dB bandwidth of 354MHz is written by a 2-ns pump1 pulse and a 100-ps pump2 pulse, where the phase of pump1 pulse is shifted with π from its middle point through phase modulation. Then, with a high repetition rate of 250MHz for both pump pulses, an enhanced PS-BDG with a deep notch depth is obtained and its notch frequency can be easily tuned by changing the phase shift. We demonstrate a proof-of-concept experiment of the transient PS-BDG and show the notch frequency changing by tuning the phase shift. The proposed PS-BDGs have important potential applications in microwave photonics, all-optical signal processing and RoF (radio-over-fiber) networks.