Basic design for highly stable mechanical optical fiber splice and its development

In mechanical splice technology, one of the basic problems is the slippage between fibers and fiber-holding substrates. We analyzed the relationship between the dimensions and material constants of a splice in a fiber butt-joint region and the force distributions along fibers, when external tensile forces or thermal stress acted on the fiber joint region. We evaluated factors relating to the slippage and these effects quantitatively. We then designed the joint region largely based on this analysis. We confirmed the joint characteristics using a temperature cycling test in accordance with the relevant Telcordia Technologies (formerly Bellcore) test specification and microscope observations of the damage to the fiber ends after the test. We achieved a highly stable mechanical splice for single fibers and four-fiber ribbons with an insertion loss change of less than /spl plusmn/0.1 dB during the test and with no damage to the fiber ends.