Fujikura Limited

Hirokuni Ogawa

Hideyuki Hosoya

Ken Sakuma

Akira Wada

Koji Omichi

Kenichiro Asano

Daigo Fujita

Shimon Ishikawa

Tomoko Shikata

Kouji Ohura

Katsutoshi Kohmoto

The present invention relates a method for manufacturing an optical coupler/splitter. A Y-shaped waveguide core is formed by focusing a laser beam into a cladding layer that is formed from a glass material. At least one portion of this Y-shaped waveguide core other than the input port and the output ports is treated as a refractive index adjustment area. After the portions of the Y-shaped waveguide core other than the refractive index adjustment area have been formed by focusing a laser beam, signal light is inputted into the input port of the Y-shaped waveguide core and the signal light outputted from the output ports of the Y-shaped waveguide core are monitored. The refractive index of the refractive index adjustment area is determined based on the result of the monitoring and is adjusted by focusing a laser beam repeatedly.

Manufacturing method for optical coupler/splitter and method for adjusting optical characteristics of planar lightwave circuit device

This two input two output type optical switch includes four one input two output type optical switches which are arranged to oppose one another, each of these one input two output type optical switches including a Y branch portion in which one optical waveguide is branched into two optical waveguides. And two refractive index adjustment means are provided in the vicinity of each Y branch portion. Switching over of the optical path is performed by half of the refractive index adjustment means functioning alternately. Moreover, a light output intensity variable attenuation function which attenuates by any desired amount the intensity of the light which is being outputted is implemented, at some input port and/or output port, by operating at least one of the refractive index adjustment means which is not currently being used for switching over of the optical path.

Optical switch, optical add-drop module, and optical communication system

In the manufacture of an arrayed waveguide grating type optical multiplexer/demultiplexer, respective slab waveguides are provided at input sides and output sides of a waveguide array in a cladding layer formed upon a substrate, which includes plural waveguides whose lengths differ and which are arranged in parallel; and an input waveguide is provided at the input side of the input side slab waveguide, while plural output waveguides are provided at the output side of the output side slab waveguide. The waveguides are made from a material for which the difference between the effective refractive indices for the two polarizations is large, and thereby, when multiplexed light which consists of plural lights of different wavelengths is inputted to said input waveguide, lights which have been separated by wavelength and by polarization are outputted from each of said output waveguides. As a result, it is possible to make a polarization/wavelength multiplex transmission circuit using fewer elements.

Optical multiplexer/demultiplexer

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Sakura, Japan

Hirokuni Ogawa