Reliability of v-grove optical fiber mass splice. improvement of splice loss temperature characteristics

• Published in: Electronics & communications in Japan. Part 1, Communications Vol. 68; no. 1; pp. 63 - 72
• Main Authors: Nagasawa, Shinji, Sankawa, Izumi
• Format: Journal Article
• Language: English
• Published: New York Wiley Subscription Services, Inc., A Wiley Company 01.01.1985
• ISSN: 8756-6621; 1520-6424
• DOI: 10.1002/ecja.4410680108

With the development of multiple optical cable and its high‐density assembly technology, the need for establishment of a technology for the mass splice of optical fibers has become urgent. Although the V‐groove mass splice method has been investigated, it has a special problem in terms of reliability because of the splice loss change with temperature. This paper proposes to determine the mechanism of change of the splice loss in order to solve this problem. The investigation has been carried out with the V‐groove mass splice which has been considered to be an important component for the mass splice of a high‐density ribbon fiber, and by examining in detail the splice‐loss temperature characteristic experimentally. The main cause of the variation of the splice loss has been found to be the change of the distance between the ends of two fibers due to the temperature change of the dimensions of the V‐grooved substrate. Although there is a slight effect due to the change of dimensions of the adhesive, it is useful to: 1) employ a material for the V‐grooved substrate which can form the substrate precisely and at the same time has a low thermal‐pansion rate; 2) to minimize the irregularity of the cut‐end surface of the fibers; and 3) to use an adhesive having a low thermal expansion rate. It has been found that even with the maximum initial cut‐end distance of 40 μm, the variation of the splice loss can be reduced to less than 0.05 dB against a temperature change between ‐30°C and +60°C by choosing the thermal expansion rate of the substrate to less than 3.3 × 10‐6/°C. This has been confirmed by the experiments with a prototype splicer using a ceramic V‐grooved substrate and epoxy‐based adhesive.