Low Cost Fiber Optic Cable Assemblies for Local Distribution Systems

This report describes the results of one year effort to develop a low cost fiber optic cable using plastic clad silica fibers. As part of the program, silica core and plastic cladding materials were evaluated with respect to optical attenuation, mechanical properties, chemical properties, and radiation hardness. Fabrication techniques were developed and means to minimize excess cable loss evaluated. Uncabled fibers were fabricated with attenuations as low as 5.5 dBkm at .79 micrometers. Three cable designs were developed one with central strength members, one with external strength members, and one with central strength members and an external braid. These designs, though developed for plastic clad silica fibers, are well suited to use with low loss doped silica fibers as well. The cables were fabricated in two phases. In the first phase, short lengths 13 km of the three designs were fabricated and subjected to optical and mechanical evaluations. Based on the results of these tests, the third design was eliminated since it was more costly and offered no advantages over other designs. In the second phase, final cable models of the central strength member and the external strength member designs were fabricated in lengths from 13 km to 1 km. The final models were subjected to optical, mechanical, environmental, and radiation evaluations. The cables met or exceeded most of the program goals.