Kddi Corporation

Other

Kdd Submarine Cable Systems, Inc.

Kddi Submarine Cable Systems Inc.

Kosuke Nishimura

Masashi Usami

Hidenori Takahashi

Munefumi Tsurusawa

Masatoshi Suzuki

Shota Ishimura

Ryo Inohara

Kazuki Tanaka

Haruhisa Sakata

Reiko Takizuka

An optical transmission system in which a transmitting station and a plurality of receiving stations are connected via an optical splitter, wherein the transmitting station includes: a controller configured to determine whether to perform intensity modulation or phase modulation on optical signals based on information on transmission distances to the receiving stations and modulation bands; an intensity modulator configured to perform intensity modulation on an optical signal; and a phase modulator configured to perform phase modulation on an optical signal, and wherein one of an intensity modulation signal and a phase modulation signal is transmitted from the transmitting station to each of the receiving stations.

Optical transmission system, PON system, and transmission method

A terminal device usable in connection with an external display device is disclosed, which receives a plurality of sub-image data sets into which an original image data set has been divided, with each sub-image data set having a size within a display area size of the terminal device; converts an image format of the plurality of sub-image data sets into the same image-format as an image format of the external display device, on a per-sub-image-data-set basis; regenerates the original image data set from the plurality of format-converted sub-image data sets, such that the original image data set is formed in its entirety or in plural data blocks; and outputs the regenerated original-image-data-set to the external display device.

Terminal device capable of outputting image data to external display device in supported image format

A chromatic dispersion device according to the invention comprises an input/output waveguide, a plurality of first ring waveguides and a second ring waveguide. The plurality of first ring waveguides optically couple with the input/output waveguide through directional coupling and are disposed along an optical axis direction of the input/output waveguide, each ring waveguide having a predetermined FSR (free spectral range) and group delay characteristics with a peak value of the same polarity. The second ring waveguide optically couples with the input/output waveguide through directional coupling, the second ring waveguide having the predetermined FSR and group delay characteristics with a peak value of a polarity different from those of the first ring waveguides.

Chromatic dispersion device

An object of this invention is to improve coupling efficiency of a silica optical waveguide having a high relative refractive index difference and a single mode optical fiber. A silica optical waveguide ( ) consists of a single mode optical waveguide, and its core ( ) is originally a rectangle. A width of the core ( ) of the silica optical waveguide ( ) is tapered at a predetermined length part ( ) connecting to an optical fiber ( ). A thickness of the core ( ) in the tapered part ( ) is constant.

Optical coupling structure

An optical circulator outputs an optical signal entered through its port A from its port B. A fiber collimator makes the optical signal spread out from the port B of the optical circulator into a collimated beam and applies it to a beam splitter. The beam splitter is disposed at an angle of 45&deg; to the optical axis. Around of the beam splitter, total reflection mirrors are disposed in three directions per angle of 90&deg; except for the direction in which the fiber collimator is disposed. The distance between the total reflection mirrors and the beam splitter is adjustable.

Dispersion compensator

An optical gate according to the invention comprises a polarization divider to divide an optical signal into two orthogonal polarization components and to output them as a first polarization component which precedes in the time base and a second polarization component which follows the first one in the time base; a semiconductor optical amplifier to modulate the phase of the second polarization component output from the polarization divider according to a control light; an assist light supplier to supply to the semiconductor optical amplifier an assist light to help the recovery of the refractive index variation of the semiconductor optical amplifier caused by the control light; a polarization combiner to combine the first and second polarization components of the optical signal transmitting on the semiconductor optical amplifier so as to adjust them in the same time location; and a polarization extractor to extract a predetermined polarization direction component from the output from the polarization combiner.

Optical gate and optical phase modulator

An optical signal processor is disclosed comprising a first optical path having a first electroabsorption optical modulator to be applied with a constant voltage and to absorb light of a signal wavelength, a second optical path having a fixed phase relation with the first optical path relative to a probe wavelength, a probe light introducer for dividing probe light of the probe wavelength into two portions and feeding them respectively into the first and second optical paths, an original signal light introducer for introducing original signal light of the signal wavelength into the first electroabsorption optical modulator, and a combiner for combining both light of the probe wavelength passed through the first and second paths.

Growing community of inventors

Kamifukuoka, Japan

Kosuke Nishimura