10 Gb/s 120-km Bidirectional Repeaterless Transmission over Single-Mode Fiber

A successful repeaterless 10 Gb/s bidirectional transmission experiment is demonstrated at the 1550 nm wavelength through 120 km of single-mode fiber. Fiber chromatic dispersion compensation in both transmission directions is realized by insertion of the same dispersion compensating fiber in the transmission fiber span. Excellent long-term error rate performance (BER < 10-¹⁴) is achieved by suppression of the Rayleigh backscattered signal power with low loss narrow-band fiber grating reflection filters.