title: Flexible all fiber Fabry-Perot filters based on superimposed chirped fiber Bragg gratings with continuous FSR tunability and its application to a multiwavelength fiber laser.
abstract: We proposed and experimentally demonstrate a simple and flexible scheme of all-fiber Fabry-Perot filter with continuous free spectral range tunability exploiting a superimposed chirped fiber Bragg grating. Then, we apply the proposed continuously tunable multichannel filter to a multiwavelength SOA ring laser at room temperature. The specially designed apparatus can induce the symmetrical strain gradient and modify the chirp ratio along the superimposed chirped fiber Bragg grating attached onto a flexible cantilever beam. Then the free spectral range of the all-fiber Fabry-Perot filter can be continuously controlled by the variation of reflection chirp bandwidth of the superimposed chirped fiber Bragg grating without center wavelength shift, which depends on the moving direction of translation stage. The proposed scheme can provide the effective multichannel filter with continuous free spectral range tunability. We successfully achieve the stable operation of a multiwavelength SOA laser with eleven lasing channels based on the proposed flexibly tunable multichannel filter at room temperature.
authors.forename: Young-Geun
authors.initials: YG
authors.lastname: Han
authors.forename: Xinyong
authors.initials: X
authors.lastname: Dong
authors.forename: Chang-Seok
authors.initials: CS
authors.lastname: Kim
authors.forename: Myung Y
authors.initials: MY
authors.lastname: Jeong
authors.forename: Ju Han
authors.initials: JH
authors.lastname: Lee