Two-Photon Interference

Abstract

Interferometry using various portions of the electromagnetic spectrum has a long history, extending back to the beginning of the nineteenth century in the optical case, and expanding far into other parts of the electromagnetic spectrum by the mid-twentieth century. During this time, interferometry has been used both as a probe for investigating the properties of light itself and as a practical tool for making high-precision measurements of other objects and phenomena. The applications range from measurement of lattice structures in solids and determination of stellar diameters to searches for gravity waves, a luminiferous ether, and extra space-time dimensions.