FIBER TYPE OPTICAL PARTS

摘要

PROBLEM TO BE SOLVED: To provide fiber type optical parts of simple constitution having sharp band-pass characteristics adequate for use in a WDM system by the fiber gratings alone. SOLUTION: The optical parts have a pair or plural pairs of the uniform type fiber gratings 11 and 12 which prohibit the passage of the light of the wavelength region on the outer side holding a prescribed wavelength region in-between with the breaking characteristics of a sharp inclination and a pair or plural pairs of the chirp type fiber gratings 13 and 14 which prohibit the passage of the light of the wavelength region on the outer side holding a prescribed wavelength region in-between with the prescribed breaking band characteristics, by which the band-pass filter of the prescribed wavelength region is built. The fiber type optical parts having the sharp band-pass characteristics are realized by integrally building multilayered dielectric film filters and array waveguide type diffraction gratings into the optical parts.