GAIN FLATTERING FILTER OF OPTICAL FIBER AMPLIFIER USING OPTICAL COUPLER OF ASYMMETRIC STRUCTURE

摘要

PURPOSE: A gain flattering filter of an optical fiber amplifier using an optical coupler of an asymmetric structure is provided to allow the gain flattering without the operation condition of the optical fiber amplifier since the gain flattering spectrum is varied in response to the parameter control of the optical coupler. CONSTITUTION: A gain flattering filter(6) of an optical fiber amplifier by using an optical coupler of an asymmetric structure includes a first optical waveguide(2), a second optical waveguide(4) and an optical waveguide moving member. The first optical waveguide(2) transmits a portion of wavelength components among the optical signals inputted thereto and outputs the remaining wavelength components to the second optical waveguide(4). The second optical waveguide(4) is placed adjacent to the first optical waveguide(2) and it connects the wavelength components transmitted thereto. And, the optical waveguide moving member is selectively mounted on the first optical waveguide(2) or the second optical waveguide(4) and it selectively performs the vertical distance control between the central waveguide axis to vary the optical coupling degree between the first optical waveguide(2) and the second optical waveguide(4) or the horizontal distance control between the central waveguide axis to vary the size of the bandwidth on the gain flattering spectrum.