| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a water immersion detection device and a method in which loss wavelength dependency is reduced. <P>SOLUTION: The water immersion detection device includes an optical fiber on which test light is incident for detecting water immersion, a water absorption medium disposed near the optical fiber, and a bend forming part forming the bend of the optical fiber when the water absorption medium is expanded by the absorption of water. The optical fiber 300 includes a W-type profile in which a ring-type low refractive index layer 303 having a refractive index lower than that of a clad 302 is adjacent to a core 301 in the clad 302, in addition to the core 301 and the clad 302. Because a light wave propagated in the optical fiber is spread as it approaches the long-wavelength side, the effect of the low refractive index layer 303 is increased in the optical fiber 300 so that confinement is intensified as it approaches the long-wavelength side. Thus, the difference in the bending loss between different wavelengths is reduced more than that of a step index type SMF. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
