Design, Construction, and Test Results for Three Different Fiber Optic Tow Cables

The design, manufacture, and testing of three armored fiber optic tow cables is discussed. The motivation for these developments was the technical need to have low-loss high-bandwidth transmission lines, that function with negligible crosstalk and absence of ground loops, placed within the limited core space of the cable. General guidelines for avoiding serious microbending loss in this type of cable structure are reviewed, and different methods of implementing the design principles are demonstrated by way of discussions specific to the three electrooptic core designs that were manufactured. A discussion is given regarding some of the practical problems associated with manufacturing. For two of the cable designS, measurements of optical attenuation with a Tektronix model 150 optical time-domain reflectometer are presented for several stages of manufacture, and approximate changes in attenuation are given for a tension loading of 33kN.