DUO-BINARY OPTICAL TRANSMITTER USING A SEMICONDUCTOR OPTICAL AMPLIFIER, PARTICULARLY FOR HAVING SIGNAL-CROSSED PHASE CHARACTERISTICS OF A DUO-BINARY SIGNAL WITHOUT USING AN ELECTRIC LOW BAND PASS FILTER

摘要

PURPOSE: A duo-binary optical transmitter using an SOA(Semiconductor Optical Amplifier), particularly for having signal-crossed phase characteristics of a duo-binary signal without using an electric low band pass filter, is provided to enhance non-linear and distribution characteristics of NRZ(Non Return to Zero) transmission. CONSTITUTION: An optical source(101) outputs a carrier. A signal generator(102) generates an NRZ data signal. A duo-binary coding unit(103) codes the NRZ electric signal. An SOA(110) modulates a phase of the optical carrier by a gain change according to a bias current applied after being coupled with the coded signal. An optical band pass filter(104) receives a phase-modulated optical signal from the SOA(110), filters it according to a determined band, and outputs a duo-binary optical signal.