Fujitsu Corporation

Kaori Odate

Motoyoshi Sekiya

Takeshi Hoshida

Olga I Vassilieva

Ryosuke Goto

Takuya Miyashita

A control method, which is applicable to a variety of network configurations, controls an optical transmission system to determine optimum optical input power to a transmission path for increased optical transmission quality. The optical transmission system has terminal stations, repeaters, dispersion compensation modules, and a dispersion compensation controller. The terminal stations transmit and receive an optical signal through an optical fiber transmission path. The repeaters are disposed in the optical fiber transmission path for amplifying the optical signal. The dispersion compensation modules are disposed in the terminal stations and the repeaters for compensating for dispersion of the optical signal. The dispersion compensation controller determines a target value for a nonlinear phase shift, which is an indication of a self-phase modulation caused by a transmission medium of the optical fiber transmission path, to have a maximum residual dispersion tolerance, and adjusts at least one of the input powers applied to transmission paths connected to the terminal stations or the repeaters and the input powers applied to the dispersion compensation modules to equalize the nonlinear phase shifts of paths in the optical transmission system to the target value.

Optical transmission system and method of controlling optical transmission system

A method is provided for transmitting information in an optical communication system that includes transmitting an optical information signal at a wavelength over an optical link with a first and second end. The optical information signal is pre-distorted for dispersion proximate the first end of the optical link. The optical information signal is then compensated proximate the second end of the optical link for dispersion, wherein the pre-distortion and the compensation have opposite polarity at the transmitting wavelength.

Method and system for transmitting information in an optical communication system with low signal distortion

In an Raman amplification control apparatus, a plurality of excitation light pulses respectively having a plurality of different wavelengths are generated; and the plurality of excitation light pulses are injected into a predetermined optical transmission line in turn at such timings that the plurality of excitation light pulses do not overlap even after propagation of a predetermined effective length of the predetermined optical transmission line. In addition, the plurality of excitation light pulses may be injected into the predetermined optical transmission line in such an order that the difference between propagation velocities (or wavelengths) of each pair of ones of the plurality of excitation light pulses successively injected into the predetermined optical transmission line is minimized.

Growing community of inventors

Kawasaki, Japan

Kaori Odate