| 摘要 |
<p>PURPOSE:To detect the generation of heat with high sensitivity by transmitting polarized light to an optical fiber and detecting the change of light output accompanied by the rotation of the plane of polarization of light caused by the bending of the optical fiber due to the thermal deformation on the shape memory alloy arranged in the vicinity of the optical fiber. CONSTITUTION:The polarized light emitted from an LED is transmitted using an optical fiber 1 such as a single mode fiber and the plane of polarization of the polarized light in the optical fiber 1 is certainly kept. A heat detecting shape memory alloy 2 is arranged in the vicinity of the optical fiber 1. When the shape memory alloy 2 is deformed by a fire or other heat, bending is generated in the optical fiber 1 and the plane of polarization of the polarized light is rotated. Light output is detected by a photodetector PD through an analyser 3 and the output fluctuation due to the rotation of the plane of polarization is detected to detect the generation of heat. Since the plane of polarization is rotated even by slight bending, the life of the optical fiber 1 is extended and detection sensitivity also becomes high.</p> |
