WAVELENGTH SELECTING OPTICAL DELAYING ELEMENT AND TIME DIVISION OPTICAL EXCHANGER

摘要

PURPOSE:To obtain the element which varies in the delay time of the light signals propagating in an optical waveguide with each of wavelengths by adjusting the reflection wavelengths of respective Bragg reflectors in such a manner that the plural light rays of different wavelengths inputted to the optical waveguide are reflected by the respectively different Bragg reflectors. CONSTITUTION:The optical waveguide 2 and the plural Bragg reflectors 3a to 3d optically coupled to the optical waveguide 2 are provided. The Bragg reflectors 3a to 3d are disposed apart intervals in a waveguide direction. The reflection wavelengths of the respective Bragg reflectors 3a to 3d are variable. The delay corresponding to the distance of twice the distance between the Bragg reflectors 3a to 3d which make reflection between the light rays of the different wavelengths is, therefore, given by previously adjusting the reflection wavelengths of the respective Bragg reflectors 3a to 3d in such a manner that the plural light rays of the different wavelengths inputted to the optical waveguide 2 are reflected by the respectively different Bragg reflectors 3a to 3d. The delay time is optically varied in this way and the optical delay element varying in the delay time with each of the wavelengths is obtd.