Audio signal distribution circuit for local optical fiber communication

Audio signal and address distribution circuits are established to construct a local optical fiber communication system. During the time of distributing an audio signal from the transmitter to the specified receiver, a series of multiple frequency address signals are issued together with the audio signal in a specific frequency domain. Since the system has an isolated transmission path actualized by optical fibers in an extremely wide frequency bandwidth, the audio signal and address can simultaneously be sent on a GI optical fiber after they are modulated by an FM square-wave