140km TOSLINK: Extending Audio Over Insane Distances

A hacker successfully transmitted a TOSLINK audio signal over 140km using SFP optical modules, far exceeding its 10-meter design limit. By creatively employing inexpensive TOSLINK ADCs/DACs, an SFP experimenter board, and DWDM fiber channels, he overcame signal attenuation and rate mismatch challenges, achieving inter-city audio transmission. While lacking practical applications, this experiment showcases deep understanding and innovative use of optical transmission technology, prompting reflection on the inner workings of optical components.