This paper describes a newly developed fully automatic arc-fusion splice machine, by which all splice processes such as stripping, cutting, alignment, fusion, and reinforcement are carried out sequentially without human intervention. Fibers are aligned by using movable arms with 2 µm position accuracy controlled by microscopic image processing. Spliced portion is reinforced by a pair of plates with hot-melt adhesive. By using the new machine, an average splice loss of 0.07 dB and a median tensile strength of 2.6 GPa with reinforcement are obtained for graded-index multimode fibers.

This paper describes a new single-unit underground radar for detecting underground buried pipes. The pipe depth can be calculated from the hyperbolic shape in the cross-sectional image of radar echoes. The edge contour of the image is extracted, and the buried depth is judged from the similarity between the extracted hyperbolic curve and the theoretical curve. A suitable amplification rate is estimated by choosing the best image from numerous cross-sectional images formed during one antenna movement repeated at different amplification rates. The best image has few pixels corresponding to weak and saturated signals. The new radar is very compact, so it can be operated by one person. Objects buried up to 2.0m deep can be detected.

A demountable optical connector for a single-mode fiber-ribbon has been developed, using a multi-V-groove molding method. The connecting loss due to the errors in ferrule fabrication has been analyzed in detail. The fabricated 5-fiber connector exhibited an average connecting loss of 0.5 dB.