10-Gb/s subcarrier multiplexed transmission over 490 km of ordinary single-mode fiber without dispersion compensation

This letter describes the results of a field trial in which four 2.5-Gb/s data channels were transmitted around the San Francisco Bay over ordinary telephone company fiber at 1550 nm with negligible dispersion penalty using subcarrier multiplexing (SCM). Using off-the-shelf microwave components and a lithium niobate external modulator having a modulation bandwidth of around 20 GHz, we were able to multiplex four tightly spaced high-speed data channels at a single wavelength. At the receiving end, we optically demultiplexed the data using optical filters and OC-48 clock recovery receivers.