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.