DUO-BINARY OPTICAL TRANSMITTER

摘要

PURPOSE: A duo-binary optical transmitter is provided to generate a duo-binary RZ(Return to Zero) optical signal without using an electric low band pass filter. CONSTITUTION: A light source(50) generates and outputs carrier that is able to carry information. A differential precoder(110) codes an inputted NRZ(Non Return to Zero) electric signal. A modulator driving amplifier(120) amplifies and outputs the coded binary signal. A Mach-Zehnder interferometer type optical phase modulator(130) phase-modulates the carrier and outputs it. A broadband pass filter(140) limits a bandwidth of the phase-modulated duo-binary optical signal. An RZ pulse generator(200) converts the NRZ-modulated signal into an RZ signal, and includes a Mach-Zehnder interferometer type optical intensity modulator(210) and a clock generator(220).