Wavelength division multiplexing all-fiber hybrid devices based on Fabry-Perot's and gratings

In this paper, we propose and experimentally demonstrate a series of new al l-fiber, tunable, and highly selective filters based on fiber gratings and Fabry-Perot's, The structures combine high fiber Fabry-Perot (FFP) selectiv ity and fiber Bragg grating (FBG) bandpass nature and presents high flexibi lity in the response by using nonuniform gratings. An ultraselective filter (a few MHz in range) is also addressed by cascading two FFP.