OPTICAL QUADRATURE AMPLITUDE MODULATION CIRCUIT AND OPTICAL TRANSMITTER

摘要

PROBLEM TO BE SOLVED: To generate a multilevel quadrature amplitude modulation signal of eight values or more by one parallel type Mach-Zehnder type amplitude modulation circuit.;SOLUTION: D/A conversion is performed to a binary data signal, the binary data signal is output as two sets of parallel binary data signals of m system and n system (m, n≥2), analog signals at a 2^m level and a 2ⁿ level are generated from the parallel binary data signals of the m system and the n system, respectively and supplied as drive signals of a Mach-Zehnder type amplitude modulation part which superimposes an in-phase component of amplitude modulation to an optical signal and a Mach-Zehnder type amplitude modulation part which superimposes a quadrature component of amplitude modulation to the optical signal, respectively.;COPYRIGHT: (C)2008,JPO&INPIT