| 摘要 |
PURPOSE:To provide the integrated wavelength filter by which a signal light intensity is increased while suppressing production of noise by a spontaneous emission light. CONSTITUTION:The integrated wavelength filter consists of a tuning variable wavelength optical filter 1, and wavelength selection couplers A, B placed in front and at the back of the optical filter. A light from an input guide path passes through a beam splitter 2a and is reflected in a distribution reflector 3a, but only a wavelength at a prescribed band depending on a pitch of grating and the shape of the guide path is reflected, the light is amplified by the optical filter 1 for a narrow band and the result is coupled with a beam splitter 2b. Only the wavelength at the tuning band of the optical filter 1 is reflected in a distribution reflector 3b, the result passes through the beam splitter 2b and is coupled with an output side guide path. Thus, a spontaneous emission light or the like with a wavelength at the outside of the tuning range caused by the optical filter 1 when the transmitted wavelength is tuned is eliminated. |
