This example demonstrates a temperature sensor based on fiber Bragg gratings (FBG). High-temperature measurements above 1000 °C are critical in harsh environments such as aerospace, metallurgy, fossil fuel, and power production. Fiber-optic high-temperature sensors are gradually replacing traditional electronic sensors due to their small size, resistance to electromagnetic. It is a single point contact temperature measurement system. A Fluorescent sensor is formed at the tip of the Optical Fiber. The light source is used to excite the Fluorescent material. The temperature-dependent change of the refractive indices of the fiber, consequently the shift of its Bragg wavelength, is used as a measure of the temperature.