| 摘要 |
PURPOSE:To increase a noise margin by sealing a substance, changing in phase from a solid to a liquid according to the ambient temperature, and a liquid of refractive index close to that of an optical fiber in the connection parts of optical fibers and by turning on-off an optical path with the liquid according to the transformation of the substance. CONSTITUTION:End parts of a couple of optical fibers 1a and 1b conected coaxially with the end surface opposing closely to each other are fitted in coupling container 2 in a liquid-tight state. Solid substance 3 changing in phase from a solid to a liquid at the transformation point is arranged to be filled the gap between the opposing end surfaces of optical fibers 1a and 1b, and liquid 4 having refractive index close to those of optical fibers 1a and 1b and stable to fluctuations of temperature is sealed with a slight gap left in coupling container 2. Up to the temperature of the transformation point of solid substance 3, the optical fibers are off and at when exceeding transformation point, solid substance 3 is liquefied and disconnected from the optical fiber end surfaces to fill the gap with liquid 4, thereby turning on the optical path. |
