Abstract

Frequency division multiple access (FDMA) optical networks can efficiently distribute information to many users within a local environment.¹ We use frequency tunable two-electrode distributed feedback (DFB) lasers for this system because of their potential for Gbit/s frequency modulation; these lasers are modulated by frequency shift keying (FSK) to avoid the large modulating current and excessive frequency chirp associated with amplitude shift keying (ASK). A tunable fiber Fabry-Perot (FFP) optical filter is employed to demodulate/demultiplex the signal, selecting one tone and rejecting all others²; the FSK signal is thus converted into the ASK format for direct detection. The above optical demodulation technique has been used to operate a single channel at 8 Gbit/s using a single electrode DFB laser and bulk FP.³

© 1990 Optical Society of America