Tunable and switchable optical bandpass filters based on phase-shifted linear chirped fiber Bragg gratings

In this report, we present a novel tunable optical bandpass filters based on thermal induced phase-shifted linear chirped fiber Bragg gratings with /spl sim/0.15 nm bandwidth, /spl sim/15 nm tuning range and larger than 25 dB rejection ratio. As a bandpass filter, it improve the transmission characteristics of phase-shifted FBG, such as bandwidth and Lorentzian shape. We are working on improve the insertion loss and the ripple in the top of the filter.