National Institute of Information and Communications Technology, Incorporated

National Institute of Information and Communications Technology, Incorporated Administrative Agency

Sumitomo Osaka Cement Co., Ltd.

Communications Research Laboratory, Independent Administrative Institution

Waseda University

Other

University of California

National Institute for Materials Science

Optoquest Co., Ltd.

National Institute of Information and Communication

Naitonal Institute of Information and Communications Technology

Tetsuya Kawanishi

Masayuki Izutsu

Takahide Sakamoto

Masahiro Tsuchiya

Atsushi Kanno

Kaoru Higuma

Satoshi Shinada

Shinya Nakajima

Naokatsu Yamamoto

Satoshi Oikawa

Junichiro Ichikawa

Shingo Mori

Toshimasa Umezawa

Akito Chiba

Keizo Inagaki

Hiroshi Harada

Kenji Kitamura

Ryo Takahashi

Takuro Sato

Sunao Kurimura

Shingo Takano

Yu Kataoka

Futoshi Yamamoto

Youichi Hosokawa

Seiji Nishi

Yoshinari Awaji

Ben Puttnam

Masaaki Sudo

Paul Kit Lai Yu

Yuya Yamaguchi

Jianxiao Chen

Sze Yun Set

Mark Kenneth Jablonski

Yuuichi Tanaka

Yoshiro Matsuo

Kenichi Kubodera

Masaru Fukumitsu

Kazuhiko Tamesue

An optical waveguide element includes a substrate, an optical waveguide disposed inside the substrate or on the substrate, and an electrode provided along the optical waveguide, working on the optical waveguide to generate a phase change in a light wave propagating through the optical waveguide. The electrode is a traveling-wave electrode. In a modulation section where the light wave is controlled by the electrode, the electrode and the optical waveguide are configured so that the phase change generated in a first modulation section located within a predetermined distance range from a downstream side end portion along a propagation direction of a traveling wave of an electrical signal propagating through the electrode has a sign opposite to a sign of the phase change generated in a second modulation section located within a predetermined distance range from an input end of the electrical signal on an upstream side along the propagation direction.

Optical waveguide element, optical waveguide device, and optical transmission apparatus

The first conductor plate has a groove portion that has a rectangular cross section and is formed in parallel with a first main surface such that the longitudinal direction becomes a first direction, and a first vertical tube portion formed in a direction away from the second conductor plate in a second direction orthogonal to the first direction and the first main surface, with a branch position in the groove as a starting point. The second conductor plate includes a reflection portion that is inserted into the groove portion in a manner protruding from a second main surface, which is a flat surface of the second conductor plate in contact with the first main surface, and has a reflection surface that reflects the radio wave, propagated along the groove portion, toward the first vertical tube portion.

Waveguide, method of manufacturing waveguide and antenna

To provide a foreign-object system which uses a plurality of radars, and which can detect a foreign object that is present on a runway or the like and which can suppress interference between radars. A foreign-object detection system including a first radar, a second radarconnected to the first radar via a network, and a signal sourcefor transmitting a synchronization signal to the first radar and the second radar via the network, said foreign-object detection system wherein interference generated due to a radar signal outputted from the second radar being reflected by a reflective body and inputted to the first radar is prevented by controlling a delay time that corresponds to |τ−τ|, where τis the time taken for the synchronization signal to be transmitted from the signal source to the first radar, and τis the time taken for the synchronization signal to be transmitted from the signal source to the second radar.

Foreign-object detection system

[Problem] To provide a camera with high sensitivity even if an output to the outside is weak. [Solution] This camera includes a light source, a demultiplexing unitwhich demultiplexes light from the light sourceinto first demultiplexed light and second demultiplexed light, a first modulatorwhich modulates the first demultiplexed light to obtain a modulated signal, an emission unitwhich emits the modulation signal modulated by the first modulator, and a phase imparting meanswhich imparts a plurality of types of phase shifts to the second demultiplexed light to obtain phase-imparted local light. The camera further includes a multiplexing unitwhich multiplexes light incident from the outside of the camera and the phase-imparted local light and obtains multiplexed light, a light receiving elementwhich detects the multiplexed light, and includes a light receiving unit, and an analysis processing unitwhich, on the basis of the multiplexed light received by the light receiving element, analyzes the position of a subject or the distance between the subject and the camera.

TOF camera

[Problem] To provide a novel optical network which can be used as an in-vehicle optical backbone network and exhibits high capacity, low delay, low power consumption, low noise and low cost. [Solution] An optical network system, wherein: a signal processing unitcontrols a light source, and generates an optical signal which includes an information portion to be read by one of the gateway units, and a continuous light portion to be written thereby; a network control unitgenerates an electrical signal which designates a gate y unitand pertains to whether the information incorporated into the optical signal is to be read or written; and when designated by the electrical signal, each of the gateway unitstransfers information to and from an electronic control unit, and reads information included in the corresponding optical signal or writes information in the continuous light portion, on the basis of the information included in the electrical signal about whether to read or write information.

In-vehicle optical network

To provide a photodetector which enables reception of massively parallel optical communication, and with which a large volume of data for multi-mode transmission or multi-core transmission can be received instantaneously at once. A photodetector comprising a two-dimensional photodetector array in which a plurality of photodetectorsare arranged in a two-dimensional array, and which includes a wirehaving a width of not more than 4 &#x3bc;m between the plurality of photodetectors. Each of the photodetectors has a light reception area with a side measuring not more than 100 &#x3bc;m. The plurality of photodetectors arranged in a two-dimensional array are spaced apart from each other by not less than 20 &#x3bc;m.

High-speed photodetector array

An extravisual obstacle detecting system includes: a radio wave receiving unitconfigured to receives a radio wave from a radio wave sourceattached to an object; one or a plurality of external sensorsattached to the vehicleand configured to detect an external obstacle; an alarm generating unitconfigured to generate a predetermined alarm, and, when the radio wave receiving unitreceives the radio wave from the object, and the external sensorsdo not detect the object, the alarm generating unitgenerates the first alarm.

Extravisual obstacle detecting system

To provide a method and device capable of easily measuring the CMRR vs. frequency characteristics of an optical receiver. Light having a measurement frequency (&#x3c9; [hz]) is split into two different paths, and a first optical two-tone signal, which is signal light and has a frequency difference (&#x3c9;&#x2212;&#x394;&#x3c9; [hz]), and a second optical two-tone signal, which is local light and has a frequency difference (&#x3c9;+&#x394;&#x3c9; [hz]), are obtained and input into a coherent receiver to be measured, wherein electrical signals output from the receiver are measured to obtain both the ratio of the intensity of a signal component having the frequency &#x3c9;&#x2212;&#x394;&#x3c9; [hz] to the intensity of a signal component having the frequency &#x3c9; [hz], which corresponds to the CMRR on the signal light side, and the ratio of the intensity of a signal component having the frequency &#x3c9;+&#x394;&#x3c9; [hz] to the intensity of the signal component having the frequency &#x3c9; [hz], which corresponds to the CMRR on the local light side.

Common mode rejection ratio measurement device for coherent optical receiver, and measurement method

To provide a method whereby a bias voltage capable of easily realizing a required extinction ratio can be controlled by utilizing a high-extinction ratio modulator even when a generic AD converter/control board is used, and a device for realizing the method. In the present invention, the step quantity (variation quantity) &#x394;V of a control voltage is no more than 0.1 times the half-wave voltage V[V]. For example, in the case of searching for the minimum point, the light intensity is measured when a bias that is larger by the step voltage &#x394;V and a bias that is smaller by the step voltage &#x394;V are applied, the current bias voltage being used as a reference, and the bias voltage is moved toward the smaller of the measured light intensities. The process of setting the moved bias voltage as a reference, comparing the light intensities for the bias points in both neighboring positions, and changing the reference bias voltage is then repeated. A configuration may be adopted whereby &#x394;V then gradually decreases in accordance with a predetermined algorithm.

Method for generating optical signal, and device for generating optical signal

To provide a self-homodyne detection communication system capable of using a space-division multiplexing signal as a signal for communication. The present invention relates to a space-division multiplexing apparatusincluding a multi-core fiberhaving multiple cores. The space-division multiplexing apparatususes cores other than a corefor self-homodyne detection among the multiple cores included in the multi-core fiberas coresfor communication. The space-division multiplexing apparatus is configured to include a pilot-tone guiding unitand a self-homodyne detection unit

Space division multiplexing apparatus including multi-core fiber and selfhomodyne detection method

The optical modulator includes optical modulation units. The plurality of optical modulation units is disposed in parallel on the same substrate. One input waveguide branches off to be connected to the Mach-Zehnder type optical waveguide of each optical modulation unit, and an entire optical waveguide is formed such that outputs from the Mach-Zehnder type optical waveguides are combined and output through one output waveguide. A modulation signal with the same intensity is applied to a modulation electrode of each optical modulation unit. In at least some of the optical modulation units, mechanical structures including the modulation electrodes of the optical modulation units are configured such that an amplitude value of an optical output modulated by the modulation signal of the optical modulation unit is &#xbd;(n is a natural number) of a maximum amplitude value in other optical modulation units.

Optical modulator

A high-speed communication control system is provided to resolve the problem of transmission delay, while a communication capacity is ensured. A communication system includes a transmission stationand a reception station. A communication systemincludes an optical fiber lineand a wireless paththat connect the transmission stationto the reception stationso that information is transmitted and received. The transmission stationincludes a communication control unitthat controls a communication path. The reception stationis able to communicate with the transmission station. The communication control unitcontrols whether the information is transmitted to the reception stationvia one of the optical fiber lineand the wireless path

High-speed communication control system

A method for evaluating a characteristic of, especially, each of Mach-Zehnder interferometers (MZIs) of an optical modulator. The method includes a step of measuring the intensity of the output of the optical modulator containing MZIs and a step of evaluating a characteristic of each MZI by using the sideband. The output intensity measuring step is the one of measuring the intensity Sof the sideband signal contained in the output light from the optical modulator. The characteristic evaluating step is the one of evaluating a characteristic of the MZIby using the S.

Method for evaluating characteristic of optical modulator having mach-zehnder interferometer

An object of the present invention is to provide a radio-on-fiber unit and a radio-on-fiber system which can transmit/receive signals at adequate rates especially, to/from a mobile device. A first aspect of the present invention relates to a radio-on-fiber unit () which includes an antenna array () and a light modulator array (). The light modulator array () comprises antenna elements () and light modulators () that are connected with the respective antenna elements via electric circuits. The optical waveguide () is composed of linear optical waveguides () that are arranged along the light modulators () included in certain lines among the light modulators (). The light modulator array () comprises reflection units () for connecting two adjacent linear optical waveguides with each other. Consequently, a signal light inputted to a light input unit () is outputted from a light output unit () via each linear optical waveguide ().

Radio-on-fiber unit and radio-on-fiber system

Problems To provide a method for evaluating characteristics of MZ interferometers in an optical modulator having a plurality of MZ interferometers. Means for Solving Problems When an optical modulator includes a plurality of MZ interferometers, the 0-degree component contains a signal derived from an MZ interferometer other than the MZ interferometers for evaluating the characteristic. For this, it is impossible to accurately evaluate the characteristic of the MZ interferometers. The present invention does not use the 0-degree component normally having the highest intensity. That is, the characteristic of the MZ interferometers are evaluated by using a side band intensity of the component other than the 0-degree component.

Method for evaluating characteristics of optical modulator having Mach-Zehnder interferometers

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Koganei, Japan

Tetsuya Kawanishi