OPTICAL TRANSMISSION SYSTEM

摘要

PURPOSE: An optical transmission system is provided to generate a duobinary optical signal without using an electrical low pass filter, and not to be influenced by a transmission characteristic for a PRBS(Pseudo Random Bit Sequence), thereby improving nonlinear and distributive characteristics. CONSTITUTION: A code conversion device converts an NRZ(None Return to Zero) signal into a duobinary signal, and outputs the converted duobinary signal. A modulator driving signal generation device inputs the duobinary signal, and generates a modulator driving signal. A Mach-Zehnder interferometer-type optical strength modulator(103) inputs the modulator driving signal, changes a phase of an optical carrier, and outputs an optical strength-modulated optical signal. An optical band pass filter(104) inputs modulated signal light from the Mach-Zehnder interferometer-type optical strength modulator(103), passes components only of a defined wavelength, and outputs a duobinary optical signal.