Abstract

Frequency-division-multiple-access systems arranged in central passive-star configurations have emerged as a promising means of building communications networks. The necessary devices and systems issues have recently undergone rapid development. Distributed feedback lasers, either fixed-frequency or frequency-tunable, generally serve as transmitters. Although amplitude shift keying is simple, it appears that the modulation format of choice may be frequency-shift keying (FSK), implemented by direct modulation of the laser injection current. FSK systems not only require smaller bias currents but also yield low-chirp compact spectra that are conveniently demodulated and demultiplexed using tunable fiber Fabry-Perot interferometers. If each channel is modulated at 1 Gbit/s, such networks can attain throughputs of several hundred Gbit/s.

© 1991 Optical Society of America