OPTICAL TEMPERATURE DETECTOR

PURPOSE:To attain self-recovery by temperature effect, and to reduce an artificial adjustment by measuring a transfer loss by using a separating/resetting means with respect to an axial cross section of an optical fiber, and detecting a prescribed temperature. CONSTITUTION:In a state that a device has reached a prescribed temperature, a shape memory effect of a compression spring A3 works, and the expanding force by this shape recovery is larger than the usual expanding force of a compression spring B4, therefore, by overcoming this force, an optical fiber 1-1 and an optical fiber 1-2 are separated together with a ferrule 2-1 and a ferrule 2-2. At the time point of the expanding force of shape recovery of the compression spring A3, and the expanding force which increases as the compression spring B4 contracts are balanced to obtain a separated distance W, the separating movement stops. A light beam projected to the optical fiber 1-1 is brought to a connection less by the separated distance W and photodetected by the optical fiber 1-2, therefore, by comparing this photodetecting quantity with a photodetecting quantity being below a prescribed temperature, a temperature detection is attained.