title: Narrowband, polarization insensitive all-fiber acousto-optic tunable bandpass filter.
abstract: We demonstrate an all-fiber acousto-optic tunable bandpass filter exhibiting narrow optical bandwidth and negligible polarization dependence by employing a novel ultraviolet (UV)-induced core-mode blocker written in a high numerical aperture (NA) fiber. It was demonstrated that the device had the measured 3-dB optical bandwidth of 0.65 nm, the polarization-dependent center-wavelength splitting of 0.05 nm and the extinction ratio of -22dB at the wavelength around 1550 nm. The details of the transmission characteristics and the loss mechanism of the core-mode blocking element inscribed in the high NA fiber are discussed.
authors.forename: Kwang Jo
authors.initials: KJ
authors.lastname: Lee
authors.forename: Dong-Il
authors.initials: DI
authors.lastname: Yeom
authors.forename: Byoung Yoon
authors.initials: BY
authors.lastname: Kim