Nec Corporation

Tadahiko Hanada

Yutaka Urino

Takashi Saito

Kouichi Suzuki

Shigeru Yoneda

Akio Furukawa

Hikaru Kouta

Mikio Oda

Taro Kaneko

Toshiyuki Kambe

Yuko Seki

Naoki Ofusa

Bent waveguide partsandon a substrateof an arrayed waveguide chiphave a core dimension allowing multi-mode operation, but they are adapted to constitute higher order mode filters with adequate combination of the relation of the height and width of waveguides and the minimum radius of curvature. Thus, with the multi-mode as preamble it is possible to cut off higher order mode light propagation by setting a small minimum radius of curvature, thus realizing single-mode light propagation and reducing the optical coupling loss through optical fibersandThus, it is possible to realize a waveguide chip and a waveguide device with the minimum radius of curvature of bent waveguides and less optical coupling loss in connection parts to optical fibers.

Waveguide device

The present invention relates to a device and a method for monitoring each of the propagated light beams that are propagated in each waveguide of an arrayed waveguide device and a method of fabricating the device. In the prior art, problems were encountered in deriving monitor light and photodetecting the derived monitor light within the waveguide substrate. In the present invention, waveguide directional couplers are formed in the spaces between the arrayed waveguides to derive a portion of the propagated light as monitor light. Cavities are provided at the ends of auxiliary waveguides connected to the directional couplers, and monitor light is guideded into these cavities. The monitor light, after being reflected upward or downward of the substrate by optical path conversion elements installed inside the cavities, is photodetected by photodiodes. The optical path conversion elements can be fabricated by inserting metal bumps into the cavities and then forming the bumps with a mold.

Optical circuit element and production method therefor, array-form optical circuit element, optical circuit device using it

An optical coupler comprises a tapered waveguide formed so that a waveguide width may be narrower as going from a predetermined starting position toward an emission end of a light signal. A difference between a first coupling factor and a second coupling factor is set within a predetermined range. The first coupling factor is the coupling factor to a waveguide having the same width as that in a first position in an inherent mode in the case where the tapered waveguide is cut in the first position. A second coupling factor is the coupling factor to a waveguide having the same width as that in a second position where is separated at a predetermined distance from the first position along a direction toward the emission end in an inherent mode in the case where the tapered waveguide is cut in the second position.

Optical coupler

An integrated type optical waveguide device includes an input section which contains at least one first optical waveguide and has at least one input end and a plurality of output ends. A phase shifter section has a plurality of second optical waveguides, each of which has one output end and one input end coupled with a corresponding one of the plurality of output ends of the input section. An output section contains at least one third optical waveguide and has at least one output end and a plurality of input ends, each of which is coupled with the output end of a corresponding one of the plurality of second optical waveguides. A material of each of the plurality of second optical waveguides is different from a material of each of the first and third optical waveguides.

Integrated type optical waveguide device

A waveguide optical switch has a waveguide whose refractive index changes can be controlled by an electro-optic effect and an UV guide waveguide for coupling an ultraviolet radiation to the waveguide. A portion of the waveguide and a portion of the UV guide waveguide make up a directional coupler.

Optical waveguide device to be optically poled, method of manufacturing optical waveguide device to be optically poled, and method of optically poling optical waveguide device

A method for fabricating an optical waveguide, comprising the following steps. That is, forming an optical waveguide on surface of a substrate via an atmospheric pressure chemical vapor deposition (AP-CVD) method using a silica raw material containing an organic material, and irradiating ultraviolet light on at least a portion of that optical waveguide. The refractive index of the portion of the optical waveguide irradiated with ultraviolet light increases. Since changing the refractive index in this way enables the formation of a diffraction grating, it is possible to manufacture optical filters and wavelength dispersion devices.

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Tokyo, Japan

Tadahiko Hanada