Development and analysis of a fiber-optic temperature sensor based on a regenerated fiber Bragg grating

Abstract

Subject of study. A fiber-optic temperature sensor based on regenerated fiber Bragg gratings is studied. Aim of study. A high-temperature sensor based on a regenerated fiber Bragg grating is developed, and a thermal study of the sensor up to a temperature of 1000°C is performed. Method. The regenerated fiber Bragg grating was produced by annealing a “seed” fiber Bragg grating recorded on SMF-28 hydrogen-loaded optical fiber in a high-temperature muffle furnace at a continuously rising temperature from room temperature to 920°C (the regeneration temperature in the case of SMF-28 fiber). The reflection coefficient of the “seed” grating was as close to 100% as possible, with a structure length of 15 mm. The heating rate was 500 deg/h. Main results. During the work and thermal studies described above, which were performed over a temperature range from +25∘C to +1000∘C with steps of 100°C, a fiber-optic temperature sensor was developed based on a regenerated fiber Bragg grating with a reflectance of about 50% and a temperature sensitivity of 14.9 pm/°C. Practical significance. The proposed method for manufacturing regenerated fiber Bragg gratings enables them to be used as the sensing element in a temperature sensor. The ability to operate at such high temperatures opens up broad potential for application to a wide range of industrial applications (such as gas turbine engines, power plants, steel mills, etc.). This method enables a fiber-optic temperature sensor to be constructed without using additional equipment or materials.