National Institute of Information and Communications Technology, Incorporated

National Institute of Information and Communications Technology, Incorporated Administrative Agency

Satoshi Shinada

Tetsuya Kawanishi

Shinya Nakajima

Naoya Wada

Masayuki Izutsu

Takahide Sakamoto

Ben Puttnam

Ruben Soares Luis

Georg Friedrich Rademacher

It is therefore an object of the disclosure of this document to attain a data transmission system with a simple transmitter implementing polarization multiplexing using either DML or EAM and a receiver with only one PD. A data transmission systemwhich comprises a transmitterand a receiver, wherein the transmittercomprises a first signal processorand an optical signal generator, the optical signal generatoroutputs an optical signal which comprises X and Y polarization components, e(t) and e(t), and wherein the first signal processorreceives a first data stream, S, and a second data stream, S, and controls the X and Y polarization components to reflect the first and the second data streams, respectively, wherein the receivercomprises only one photodetectorand a second signal processor

Polarization division multiplexing intensity modulation system and method using the system

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

Problem An object is to provide a method for evaluating characteristics of individual Mach-Zehnder (MZ) interferometers in an optical modulator which includes a plurality of MZ interferometers, Means for Solving Problems The method comprises a step for adjusting a bias voltage of the MZ interferometer, a step for eliminating zero-order components, a step for measuring an output intensity and a step for evaluating characteristics. An optical modulator () includes the first MZ interferometer () and the second MZ interferometer (). The first MZ interferometer () includes wave-branching section (). Two arms (), wave coupling section () and electrodes which is not shown in figures.

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

A photoelectric oscillator includes a laser beam projection unit; an optical modulator on an optical path extending from the projection unit, which optical modulator outputs a modulated signal or an optical signal containing a harmonic of the modulated signal and includes a modulation electrode whose resonant frequency band includes the frequency band of the modulation signal; a photoelectric converter for converting the output of the optical modulator to an electric signal; a feedback circuit for selecting from the radio-frequency electric signal obtained from the photoelectric converter an electric signal to be re-supplied to the optical modulator; and an output section for outputting an optical signal containing the modulation signal or a harmonic of the modulation signal or outputting the modulation signal or a harmonic of the modulation signal. A laser beam of sufficient intensity is input from the projection unit to produce a radio-frequency electric signal in the feedback circuit, and the radio-frequency electric signal or an optical signal containing the radio-frequency electric signal or the radio-frequency signal is output from the photoelectric oscillator.

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Tokyo, Japan

Satoshi Shinada