| 摘要 |
PURPOSE:To obtain an optical wavelength multiplexer/demultiplexer with a wide transmission band width in each wavelength channel by arranging a dispersing/dividing grating having 60 deg. vertical angle and formed like steps between diffraction gratings on an optical path. CONSTITUTION:In the multiplexer/demultiplexer for wavelength-selectively coupling one optical fiber 1 with plural optical fiber arrays 5 through diffraction gratings, two diffraction gratings 2, 3 for passing light beams are arranged in an optical path from an input fiber to an output fiber and the dispersing/ dividing grating 3 having 60 deg. vertical angle and formed like steps is arranged between the two diffraction gratings and the incident/outgoing direction of light to/from the grating 3 is parallel with respective inclined surfaces of grooves of the dispersing/dividing grating 3. The size of wavelength dispersion of the 2nd diffraction grating 4 is the same as that of the 1st diffraction grating 2 and respective wavelength dispersion is constituted so as to be canceled with each other. Thereby, light beams transmitted through a lens 9 and converted on respective optical fibers of the optical fiber arrays 5 arranged in respective wavelength bands include light with a wide band out of light beams in the same wavelength band. |
