TABLE OF CONTENTS You've probably heard the saying, "A chain is only as strong as its weakest link." In fiber optics, any splice is potentially the weakest link. Performed properly, the splice will attenuate the signal only slightly from about 0.05 dB to 0.15 dB, typically. Performed poorly, a splice can leak light, reflect a signal back down the transmission path, or separate completely, requiring expensive troubleshooting and repair.
In this chapter, we will discuss fiber optic splices. We will describe the factors that affect the way a splice carries optical signals and the effects on the signals themselves. We will also describe different tools and methods used to splice optical fibers as well as standards used to gauge splice performance.
A splice is a direct, permanent connection between two optical fiber ends. As with electrical wire splices, optical fiber splices may be used to add length to an existing fiber or to repair a broken or damaged fiber. However, while electrical splices only require firm, clean contact between two pieces of wire and permanent fastening using solder or a crimp connector, optical fiber splices require a great deal of precision and careful preparation of the fiber ends if they are to be spliced properly. The fiber cores must align precisely to prevent any loss of light across the splice.
Considering the size of most fibers in use and the tolerances required to align the fiber cores with each other, each successful splice is a triumph of training and technology. There...
