Title :
Optical coherent broad-band transmission for long-haul and distribution systems using subcarrier multiplexing
Author :
Watanabe, Shigetaka ; Terahara, T. ; Yokota, I. ; Naito, Tomoyuki ; Chikama, T. ; Kuwahara, Hideo
Author_Institution :
Fujitsu Lab. Ltd., Kawasaki
fDate :
1/1/1993 12:00:00 AM
Abstract :
Signal multiplexing techniques for coherent optical transmission are compared, and appropriate application for a coherent subcarrier multiplexing (SCM) system is discussed. Optical frequency modulation (FM) using direct modulation of a distributed-feedback laser diode (DFB-LD) and a heterodyne detection is shown to be feasible. A transmission system using a local laser in the transmitter is unaffected by polarization and is cost effective. Phase noise can be suppressed by a phase-noise-canceling circuit (PNC) in a heterodyne receiver. This circuit can also effectively compensate for the frequency of instability of light sources. A theoretical simulation of a coherent SCM system showed that 100 channels of 30-MHz FM signal or 15 channels of 155-Mb/s signal can be distributed to 10000 subscribers using single-stage or double-stage optical amplifiers
Keywords :
broadband networks; demodulation; distributed feedback lasers; frequency modulation; optical communication equipment; optical links; optical modulation; optical receivers; semiconductor lasers; subcarrier multiplexing; 155 Mbit/s; 30 MHz; FM signal; SCM; broad-band transmission; coherent SCM system; coherent optical transmission; cost effective; direct modulation; distributed-feedback laser diode; distribution systems; double-stage optical amplifiers; frequency modulation; heterodyne detection; heterodyne receiver; light source frequency instability compensation; local laser; long-haul optical links; optical modulation; phase noise suppression; phase-noise-canceling circuit; single-stage; subcarrier multiplexing; subscriber loops; Circuits; Diode lasers; Frequency modulation; Laser noise; Laser theory; Optical mixing; Optical modulation; Optical noise; Optical receivers; Optical transmitters;
Journal_Title :
Lightwave Technology, Journal of
