Nippon Telegraph and Telephone Corporation

Keita Yamaguchi

Kenya Suzuki

Takashi Go

Osamu Moriwaki

Ai Yanagihara

Seiji Okamoto

Shuto Yamamoto

Tetsuro Inui

Hideki Nishizawa

Shunichi Soma

Seiki Kuwabara

Mitsumasa Nakajima

Kazunori Seno

Kazunori Senoo

Yutaka Miyamoto

Toshikazu Hashimoto

Takashi Goh

Masashi Miyata

Hirotaka Ono

Yuzo Ishii

Etsu Hashimoto

Shingo Kawai

Mitsunori Fukutoku

Yuko Kawajiri

Koichi Hadama

Joji Yamaguchi

Naru Nemoto

Yoshito Jin

A waveguide bend which has low loss while keeping the curvature radius small in a waveguide with a given A is realized. An optical waveguide has a straight waveguide and a waveguide bend connected to each other, and tapered waveguide bends inserted between the straight waveguide and the waveguide bend, a curvature radius of the tapered waveguide bend being equal to a curvature radius of the waveguide bend, a waveguide width of the tapered waveguide bend changing continuously from the waveguide width of the straight waveguide at the connection point to the waveguide width of the waveguide bend. A waveguide width of the waveguide bend is larger than a waveguide width of the straight waveguide at a connection point and the tapered waveguide bend and the straight waveguide are connected with an optical axis of the tapered waveguide bend and an optical axis of the straight waveguide being offset.

Optical waveguide

A high-performance optical and electronic integrated switch capable of effectively extending the transmission distance includes a network processor that controls the functions of the packet switch, a plurality of optical transceivers provided near the processor and having a photoelectric conversion function, and an optical relay switch. A plurality of optical waveguides are connected to the input and output sides of the optical relay switch. Each optical transceiver has a regeneration function that performs optical-electrical conversion on inputted optical signals, then turns back the converted signals, and performs signal conversion on them, and its input side is connected with a routing optical waveguide included in the optical waveguides on the output side of the switch and its output side is connected with a routing optical waveguide included in the optical waveguides on the input side of the switch. The optical waveguides include ones for connecting to an external communication counterpart.

Optical and electronic integrated switch

In a waveguide having a given Δ, a low-loss waveguide bend is realized while the curvature radius is kept small. In an optical waveguide in which a first waveguide and a second waveguide are connected, a clothoid tapered waveguide bend is inserted between the first waveguide and the second waveguide. In the clothoid tapered waveguide bend, the waveguide width continuously changes from a first waveguide width at a connection point of the first waveguide to a second waveguide width at a connection point of the second waveguide, the curvature radius continuously changes from a first curvature radius at the connection point of the first waveguide to a second curvature radius at the connection point of the second waveguide, the first waveguide width and the second waveguide width are different from each other, and the first curvature radius and the second curvature radius are different from each other.

The present invention realizes an optical signal processing device that enables using a thermal oxidation silica film as the under clad of a silica PLC while also increasing the thickness of the under clad and reducing the time required for film growth during manufacturing. The optical signal processing device is formed as a planar optical circuit that includes an optical waveguide formed on a silicon substrate, and has a phase modulation element that employs a thermo-optical effect. A plurality of silica films are provided between a core of the optical waveguide and the silicon substrate, and at least one of the silica films was formed by thermal oxidation.

Optical signal processing apparatus and manufacturing method thereof

In order to reduce the number of power driving elements, an optical signal processing device includes a control unit, a current generation unit, a connection portion, and an optical signal processing unit, the current generation unit includes one or a plurality of power driving elements s, the optical signal processing unit is an optical waveguide on a substrate, and a plurality of driven elements are connected in parallel to an identical one of the plurality of power driving elements and are driven.

Optical signal processing apparatus

To provide an optical signal processing device capable of reducing the crosstalk while narrowing the space between switch elements for downsizing, the optical signal processing device includes a plurality of input optical waveguides, a plurality of output optical waveguides, a plurality of optical waveguide elements arranged between the plurality of input optical waveguides and the plurality of output optical waveguides, and a connection optical waveguide. The connection optical waveguide positioned closely to the optical waveguide element is differentiated in propagation constant from the optical waveguide configuring the closely arranged optical waveguide element. The connection optical waveguide positioned closely to the optical waveguide element is a connection optical waveguide having one end or both ends connected to the optical waveguide element, or a connection optical waveguide having both ends not connected to the optical waveguide elements.

An optical and electronic integrated switch includes a network processor that controls the functions of the packet switch, a plurality of optical transceivers having photoelectric conversion functions, and a plurality of optical switches. The optical switches include different types of optical core switch and a plurality of optical-path selection switches. The optical transceivers provided near the processor have a regenerative relay function that regenerates optical signals and turns back the optical signals, and perform optical communication with a communication counterpart via the optical switches. In the optical communication, optical switches of the different types can cooperate to set paths for optical cut-through in which path selection is performed such that inputted optical signals are outputted without the intervention of the processor. This optical cut-through can be effectively performed without imposing a signal processing burden that consumes electric power on the processor.

The positions at which electrode pads are arranged can be made more flexible, and electrical interconnects to be installed can be reduced. In addition, the degree of integration of a chip increases, making it possible to realize a large-scale device (optical switch etc.). In an optical module of the present invention, an interposer (an electrical connection intermediary component with electrode pins attached onto upper and lower faces in an array) is laid over a chip that includes a device configured by using a planar lightwave circuit (PLC) fixed onto a fixing metal plate, and a control substrate for driving the device is laid over the interposer. These components are mechanically fixed by a fixing screw or the like, and the electrode pads of the chip and the control substrate are connected to each other via the interposer.

Optical module

A photonics-electronics convergence switch with which, even if an optical network system is built by combining a plurality of packet switches, the amount of processing in the packet switches does not increase, the optical network system operates with low electric power consumption, and this enables wide-range optical communication between the nodes of a communication origin and of a communication partner, includes a network processor that is an electronic circuit configured to control the functions of the packet switch, a plurality of optical transmitter-receivers having photoelectric conversion functions, and a plurality of optical switches. Different types of optical switches cooperate to select a path through which inputted optical signals or optical signals inputted from a different packet switch connected to the packet switch are outputted to a different packet switch without passing through the processor and a path through which inputted optical signals or optical signals inputted from a different packet switch pass through the processor and are subjected to photoelectric conversion.

A photo-electron fusion switch that can perform optical communications without any trouble, even when nodes of a communication source and a communication partner that are large in transmission capacity are connected, and makes it possible to realize a concentrated arrangement of devices having similar functions and reduce the communication processing time is connected to communication source's information processing devices and communication partner's information processing devices and information processing devices that are each different in transmission speed so as to configure an optical network system. The photo-electron fusion switch includes a network processor of an electronic circuit for controlling packet switch functions, a plurality of optical transmitter/receivers that can support coherent communications and has a photoelectric conversion function capable of transmitting and receiving optical signals different in transmission speed, an optical line switching device, and a plurality of multiplexing/separators. Each multiplexing/separator simultaneously transmits and receives respective optical signals different in transmission speed to and from the nodes via optical waveguides.

Optical and electronic integrated switch and optical network system

An optical switch is configured by providing a planar lightwave circuit layer on a top surface of a Si substrate. The circuit layer forms, on the top surface of the substrate, an optical waveguide including an underclad layer, an optical waveguide core, and an overclad layer. The optical waveguide is provided to have a structure configuring a Mach-Zehnder interferometer. A heater is provided at a position just above an arm of the core on the top surface of the clad layer, and power supply electric wires are electrically connected to both ends of the heater. In a local portion including an interface between the clad layer and the top surface of the substrate, trench structure portions as concave grooves are provided.

Optical module and manufacturing method thereof

An optical signal processing device is described herein for reducing electric wirings in an optical switch or an optical filter realized using an optical waveguide. The optical signal processing device includes an optical waveguide formed on a substrate. In the optical signal processing device, the optical waveguide includes at least one input port and at least one output port, a plurality of driven elements are provided including a phase shifter that produces a phase shift to an optical signal from the input port, each of the driven elements includes at least two control terminals, control wirings are provided to have control signals being time-division synchronized applied between the two control terminals, and the control wiring for accessing the driven element is shared by the plurality of driven elements.

Optical signal processing device and method for controlling same

In an optical switch array on which optical switches that require individual electric wires are integrated, the present invention provides an optical switch array and a multi-cast switch in which the electric wires are shortened by optimizing the arrangement of the optical circuit portion. In the optical switch array in which three arrays of 1&#xd7;4 switch circuits are disposed in parallel, the position where each optical switch is disposed is sequentially shifted by Dy in the y axis direction. That is, in the case where an adjacent 1&#xd7;4 optical switch circuit exists on both sides, the 1&#xd7;4 optical switch located there between is located at the center of the two 1&#xd7;4 optical switch circuits, which are adjacent in the y axis direction. Each of the three 1&#xd7;4 optical switch circuits that are arrayed are disposed at a position shifted from the adjacent 1&#xd7;4 optical switch circuit by Dy in the y axis direction, in accordance with the positional coordinate in the x axis direction, and the electric wires at the ground side are shared such that each optical switch circuit is located sequentially shifted by Dy in the &#x2212;y axis direction.

Optical switch array and multicast switch

Provided is a variable wavelength filter having a wide variable wavelength range. In the variable wavelength filter, a slab waveguide that is a component of an arrayed-waveguide grating has a groove into which a resin is inserted. The groove intersects with a plurality of line segments A joining a place of connection between an input light waveguide and the slab waveguide to places of connection between respective array waveguides and the slab waveguide. The groove is formed such that a total length LA of an intersection of the groove and each of the line segments A monotonously increases or decreases between the adjacent line segments A with a difference in the total length LA between the adjacent line segments A being constant.

Variable wavelength filter

An optical node device includes: a multicore optical amplification unit that amplifies collectively light transmitted along a multicore fiber; a separation unit that inputs the amplified light in each core to each of a plurality of input-side single-core fibers; an optical cross-connect switch that attenuates the light input from each of the plurality of input-side single-core fibers through an optical attenuator, separates the light in accordance with a wavelength, and outputs the separated light to an output-side single-core fiber of a plurality of output-side single-core fibers related to a respective output destination; a plurality of single-core optical amplification units that amplify the light transmitted along the corresponding output-side single-core fibers; and an output unit that outputs the light transmitted along each of the plurality of output-side single-core fibers to a multicore fiber. A control unit controls the optical attenuator and the single-core optical amplification unit based on input signal optical power and output optical signal power.

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Musashino, Japan

Keita Yamaguchi