PHASE-MODULATED FIBER OPTIC TELECOMMUNICATIONS SYSTEM

摘要

A fiber optic data transmission system includes a transmitter (10) having a laser (12) emitting a continuous wave light, the transmitter including a phase modulator (16) phase modulating the continuous wave light and a control circuit (18) controlling the phase modulator as a function of an electronic input data stream having a time delay, so as to create a phase-modulated optical signal. An optical fiber (20) transmits the phase-modulated optical signal (22). A receiver (30) includes an interferometer (40) for receiving the phase-modulated optical signal, the interferometer having a first arm and a second arm, the second arm being longer than the first arm. The interferometer thus has an interferometric delay corresponding to the time delay and a phase difference imparted by the first and second arms. The control circuit can impart a phase to represent a binary zero or one as a function of the phase difference.