OPTICAL EXTERNAL MODULATOR FOR OPTICAL COMMUNICATION AND TWO-WAY OPTICAL COMMUNICATION SYSTEM USING THE SAME

摘要

PURPOSE:To provide the optical external modulator applying polarized plane modulation to an incident light without adjustment of the polarization state of 71 light made incident on the optical external modulator and the 2-way optical communication system using it. CONSTITUTION:The optical external modulator is provided with a polarization plane modulation section 11 in which a polarized state of light changes with a modulation signal through application of a stress to an optical transmission line 7, a phase change section 8 changing a phase difference between an X component and a Y component of the light propagated through the optical transmission line 7 by a value (2m-1)*pi/4 (m is a positive integer) and a reflecting section 20 reflecting the propagated light and they are arranged in this order. In the two-way optical communication system, the master station has a light source and an incoming signal use receiver and the slave station is provided with an outgoing signal use receiver receiving an outgoing signal sent from the master station and an incoming signal transmitter section and the incoming signal transmission section uses any of the optical external modulators described in the claims 1 to 12.