Modes and states in quantum optics

Abstract

Quantum states of light are at the same time endowed with two superposition principles: the one of the classical Maxwell waves and the one of the quantum states occupying these waves. This article reviews the interplay between these two aspects of quantum optics. A summary of the description of multimode quantum states is presented along with an example of the characterization of correlations and entanglement with applications in metrology and quantum computation.