Reflectivity and Bandwidth Modulation of Fiber Bragg Gratings in a Suspended Core Fiber by Tunable Acoustic Waves

The acousto-optic modulation of fiber Bragg gratings in a four-hole suspended core fiber is experimentally demonstrated. Strong modulations with a reflectivity amplitude decrease by up to 67% and a 57% bandwidth increase in the Bragg resonance are obtained for gratings of 0.26- and 1-nm 3-dB bandwidths, respectively. The reduction of the required acoustic power for achieving the acousto-optic modulation compared to conventional solid-core single-mode fibers points to more efficient modulator devices in suspended core fibers.