Mitsuru Miyauchi

Design and development of an automatic cutting tool for optical fibers

A new type of automatic cutting tool for obtaining good fiber end-surface has been proposed. In principle, a bare fiber is scored by rotating a broadaxe-shaped blade, while the fiber is supported by two magnetic clamps. The fiber is then fractured by applying bending and tensile stresses. The tool is 10 cm wide, 7.5 cm high, 9 cm long, weighs about 500 g, and is battery-driven. Optimum cutting conditions have been investigated, revealing that the blade pressure should be 10 g, bending stress should be 15 kg/mm2, and tensile stress should be 6 kg/mm2. Under these conditions, an average endface inclination of 0.42 ° is easily obtained. Stable cutting is confirmed during 1000 cutting trials, with a failure rate of 0.3 percent.

Design and characteristics of reinforcement method for fusion spliced optical fiber

In developing a reinforcement method, optimum material and structure must be selected to prevent optical-fiber failure. This paper discusses a splice reinforcement element to compensate for shrinkage of the plastic coating due to aging and thermal cycling. In prior designs, shrinkage causes buckling and increases the failure probability of the reinforced section. Also, torsion propagation, introduced during fabrication of the splice, shows an adverse effect. These concepts have not been considered up to now and the new reinforcement method, using a heat shrinkable tube, shows good performance. The loss increase at a spliced portion without nylon coating, where a heat shrinkable tube is used, is below 0.02 dB at -70°C. It has also been verified that proof testing with approximately 15-kg/mm2proof stress is necessary for long-term durability of a spliced portion with a reinforcement element.