Bandpass all-fiber acousto-optic tunable filter

Traditionally,acousto-optic tunable filters based upon single mode fiber are of band-stop spectrum.In this paper,a seldom-reported bandpass tunable optical filter is demonstrated.The bandpass bacousto-optic tunable filter is realized with a single mode fiber,on which special structure is designed.The band-pass filter with a wide tunable-range,zero frequency shift and low polarization sensitive characteristics.