High Temperature Accurate Monitoring Based on Phase-Shifting Grating and Photoelectric Oscillation

A high temperature real-time accurate monitoring system based on photoelectric oscillation had been proposed and demonstrated. We use the narrow bandwidth characteristics of phase-shifting fiber Bragg grating (PS-FBG) to generate stable photoelectric oscillation signals. After the PS-FBG is ceramic packaged to adapt to and apply to 500 °C high temperature, the wavelength shift caused by temperature change is precisely responded by narrow linewidth PS-FBG, so the change of photoelectric oscillation signal can be monitored in real time with high precision. The experimental results show that the sensitivity is −1.24 GHz/°C and the linearity is −0.99953. The system has a resolution of 0.0083 °C. The test system has excellent potential application value in precise control of high temperature environment such as metal smelting, crystal growth, chemistry and pharmaceutical engineering.