Single-Photon Detector for Potential Encryption and Sensing

Light is widely used for communications, carrying phone conversations and video signals through fiber optic cables around the world in pulses composed of many photons. Single photons are the weakest signal that can be transmitted and they have a wide range of applications including implementing an encryption technique called quantum key distribution and creating high-resolution maps. Single photons of light typically have very little energy, making them difficult to detect.