An introduction to quantum interferometry: Young's experiment with fock and coherent states

Abstract

Quantum interferometry uses the quantum properties of light to surpass the Rayleigh diffraction limit inherent in classical interferometry. We have used Fock and coherent states, which describe the electromagnetic input field, a multi-photon counting apparatus, and an operator-based approach to a multi-slit Young's experiment to present the principles behind quantum interferometry. Our calculations show interference fringes that depend on the wavelength of the source $ \lambda$, the number of slits in the Young's screen---both characteristics present in the classical scheme---, and the number of photons $m$, that the measurement apparatus detects. The latter dependence generates an effective de Broglie wavelength, $\lambda/m$, a phenomenon that can only be observed by taking advantage of the quantum properties of light.