title: Two-stage hybrid optimization of fiber Bragg gratings for design of linear phase filters.
abstract: We present a new hybrid optimization method for the synthesis of fiber Bragg gratings (FBGs) with complex characteristics. The hybrid optimization method is a two-tier search that employs a global optimization algorithm [i.e., the tabu search (TS) algorithm] and a local optimization method (i.e., the quasi-Netwon method). First the TS global optimization algorithm is used to find a "promising" FBG structure that has a spectral response as close as possible to the targeted spectral response. Then the quasi-Newton local optimization method is applied to further optimize the FBG structure obtained from the TS algorithm to arrive at a targeted spectral response. A dynamic mechanism for weighting of different requirements of the spectral response is employed to enhance the optimization efficiency. To demonstrate the effectiveness of the method, the synthesis of three linear-phase optical filters based on FBGs with different grating lengths is described.
authors.affiliation: Photonics Research Center, School of Electrical and Electronic Engineering, Nanyong Technological University, Singapore 639798.
authors.forename: Rui Tao
authors.initials: RT
authors.lastname: Zheng
authors.forename: Nam Quoc
authors.initials: NQ
authors.lastname: Ngo
authors.forename: Nguyen
authors.initials: N
authors.lastname: Le Binh
authors.forename: Swee Chuan
authors.initials: SC
authors.lastname: Tjin