| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a relatively low-cost thermometric device constituted to make laser pulse beams from a light source device incident to the end part of a coated optical fiber and to measure the change of the laser beams by a measuring device. SOLUTION: Particles 8 of material with a high coefficient of thermal expansion are uniformly mixed in a primary coating layer 6 covering a bare optical fiber 5, and it is so constituted that when the thermal expansion change of the particles 8 occurs due to the change of temperature, pressure applied to the bare optical fiber 5 along its radial direction changes according to the temperature. The change of the pressure applied to the bare optical fiber 5 along its radial direction results in the corresponding change of bend loss, and the temperature change of that part can be calculated by measuring the bend loss.</p> |
