Patent ID: 6549328
Filing Date: 2003-04-15
Classification: G02F

Abstract:
An acousto-optic tunable filter in which a plurality of areas, each provided with an optical filter configuration capable of varying a selected wavelength, for performing selection of optical signals based on mode conversion using the acousto-optic effect, are respectively connected via a mode branching device,wherein at least one area of the plurality of areas functions as a mode coupling section that mode converts an optical signal corresponding to the selected wavelength, at least one of other areas functions as a wavelength characteristic flattening section that again mode converts only the optical component of a part of the selected optical signal mode converted by said mode coupling section in the vicinity of a center wavelength thereof, and said mode branching device connected to an output side of said wavelength characteristic flattening section, branches said selected optical signal except for the optical component mode converted by said wavelength characteristic flattening section, to output the branched selected optical signal, to thereby perform flattening of the wavelength characteristics in the vicinity of the center wavelength of the selected optical signal.