ALL-FIBER ACOUSTOOPTIC TUNABLE NOTCH FILTER WITH ELECTRONICALLY CONTROLLABLE SPECTRAL PROFILE

We demonstrate a novel all-fiber acousto-optic tunable notch filter ba sed on coupling to cladding modes in a single-mode fiber. The device h as the advantage of low loss (<0.1 dB) and low polarization dependence . By coupling input light to multiple cladding modes by use of multipl e acoustic waves, we achieved an electronically controllable variable spectral profile without a significant coherent cross-talk problem. (C ) 1997 Optical Society of America.