ELECTRIC FIELD-DETECTING OPTICAL DEVICE AND TRANSCEIVER

摘要

PROBLEM TO BE SOLVED: To prevent deterioration in communication quality even in an electric field-detecting optical device using a light intensity modulator for electric field detection. SOLUTION: An electric field-detecting optical unit 115a includes: a laser diode 121; a polarization beam splitter 139 for splitting a laser beam emitted from the laser diode 121 into different first and second laser beams; and a light intensity modulator 124 to which an electric field of an object to be detected is coupled and which modulates a light intensity of the first laser beam based on the coupled electric field. A light-receiving circuit 152a includes: a first photodiode 143a for converting the light intensity of the first laser beam modulated by the light intensity modulator 124 into a voltage signal; a second photodiode 143b for converting the intensity of the second laser beam split by the polarization beam splitter 139 into a voltage signal; and a differential amplifier 112 for differentially amplifying the voltage signal converted by the first photodiode 143a and the voltage signal converted by the second photodiode 143b. COPYRIGHT: (C)2007,JPO&INPIT