| 摘要 |
PURPOSE:To decrease an excessive loss and the change of a light distribution deviation against a temp. fluctuation and to prevent the drift fluctuation of a light signal so as to obtain high reliability by covering a glass tube and adhesive agent part with a cushion material. CONSTITUTION:The glass tube 2 and the adhesive agent part 4 are covered with the cushion material 5. Soft and spongy materials such as, for example, polyurethane, polystyrene, phenolic resin and urea resin and heat insulating and heat keeping high-polymer materials such as soft vinyl chloride, vinylidene chloride and cellulose acetate are usable for the cushion material. The cushion material 5 is further covered with a heat shrinkable tube consisting of a high- polymer material. The cushion material 5 improves the low-temp. characteristic in the temp. characteristics of an optical start coupler having the twisted, fused and stretched parts of optical fiber bundles 1a, 1b in the glass tube 2. |
