BraggSenz sensor system works on fiber Bragg grating (FBG) technology designed for multi-point temperature, strain, load, and vibration measurement over hundreds of meters of fiber optic cable in extremely harsh environments. This review provides a comprehensive overview of FBG sensor technology. Our Fiber Bragg Grating Arrays are available in a wide range of optical specifications. 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. It is suitable for temperature monitoring and fire alarm.