Loose Tube Splices for Optical Fibers

Abstract

A technique for splicing optical fibers has been developed that uses a self-aligning square cross-section tube, with inner dimensions slightly larger than the optical fiber. A total loss of 0.58 dB was obtained for eight splices connected in series using a graded-index fiber with a 68-µm core diameter. The splices were made one at a time without the use of microscopes or micromanipulators; however, the fabrication process could be mechanized and extended to groups of fibers. A holding fixture could be added to adapt this technique to a connect-disconnect type splice. The size of the splice is presently 0.012 in. square, making it suitable for use within cables. Measurement set refinements that were needed to measure individual splice losses as low as 0.05 dB include an improved detector and means for better control of launching conditions.