English: See how the light changes as it travels through the polarizer. Scientists can make devices that emit photons one at a time, all with the same polarization. They can also use a combination of lenses (similar to those in eyeglasses), mirrors and crystals to manipulate and measure photon polarization. It turns out that polarization is one of the simplest properties of light to work with and so it is commonly used for storing a quantum bit, entangling photons and processing quantum information.