A 2 km Optical Fiber Communication Trial

This paper describes a recent field trial of an optical fiber communication link. The fixed point-to-point full duplex link used low loss multi-mode fibers fabricated by the CVD process in a simple cable structure. Fiber loss was approximately 4 dB/km before cabling and up to 7 dB/km after cabling. Digital 5 Mbit/s throughput TDM terminals were used to multiplex a variety of signal sources, including voice and data onto the fibers. Cabled fiber losses over 2.3 km were low enough to permit the use of incoherent infrared LED's as sources and silicon PIN photodiodes as receivers. 'Vee' groove splices were employed to connect fibers in the field. Installation was by standard cable laying techniques and no special problems were encountered.