Fiber optic sensors use optical principles to detect physical quantities. Fiber optic current sensors are revolutionizing the way electrical currents are measured, providing high sensitivity, immunity to electromagnetic interference (EMI), and the ability to function in harsh environments. Sensing is achieved by. Jose Miguel Lopez-Higuera: Handbook of Optical Fiber Sensing Technology, John Wiley & Sons, 2002. P 603 Radiation absorption excites an orbital electron to a higher energy level. Salih, Monserrat Gutiérrez Muñoz, Fahad Alam, Bader.