Arc‐fusion splice of multimode optical fibers using pre‐fusion method

Abstract

In optical fiber splicing, the fusion technique using gas discharge heating is considered a practical method from the viewpoints of operation and reliability. The fusion by which the splicing is made after pre‐shaping by a gas discharge on the optical fiber ends, has excellent features of low loss and stable splices. However, the splicing mechanism and the optimum splicing condition have not yet been analyzed sufficiently. This paper studies splicing conditions such as the pre‐fusion time, optical fiber stuffing length and shape‐up time of the optical fiber splicing by pre‐fusion method from the viewpoint of splicing shape, splice loss and core distortion. The optimum conditions for realizing a low‐loss splice are then determined. As a result, it is clarified that although the pre‐fusion method essentially becomes a mechanism for increasing the splice loss due to core distortion caused by pre‐fusion, there exists an optimum stuffing length for minimizing its effect. It is also shown that for performing stable, low‐loss splicing (even in the case where the condition of the optical fiber end is bad), it is proper to have a pre‐fusion of 0.3 ∼ 0.4 second. A foundation for the design of the splicing apparatus is obtained.

Fundamental study on optical fiber direct transfer splicing

“…To obtain a stable fiber end fixed in the holder, the length of the V groove is required to be 3 mm; and, therefore, the length of the fixed end becomes 3 mm. In arc fusion splicing, the required fixed end separation is reported to be about 5 mm [9]. Further, in this method, concerning the linked part, the fusion splicing with shielded heating in relation to the intensity distribution has been investigated; and it is reported that the separation between the ends can be as short as 1.5 mm [lo].…”