Fiber Optic Sensor for Cryogenic Liquids
摘要
Classical fiber optic physical sensors have intra-fiber structures that change the back-reflection response as environmental conditions change. These structures are often a modification of the fiber core glass. But, there are sensors that are the incorporation of a gas or liquid cell into the fiber core. Such a structure works as a Fabry–Pérot interferometer, it can also work as a threshold sensor when the aggregate state of the cell changes. This paper deals with the structure in the fiber created by the fuse effect. The cells of this structure contain oxygen at pressures from 4 atm. These cells work as a threshold sensor that can indicate the presence of cryogenic liquid. The purpose of the present study is to determine the dependence of the change in back reflection on temperature.