Quantum optics

Abstract

Quantum optics is the study of the quantum theory of light at low energies and interactions with bound electronic systems. We discuss physically achievable states of the electromagnetic field, including squeezed states and single photons states, as well as schemes by which they may be generated and measured. Measured systems are necessarily open systems and we discuss how dissipation, noise and decoherence is treated in quantum optics in terms of Markov master equations, quantum trajectories and quantum stochastic differential equations. Quantum optics has recently proved a valuable test-bed to implement new communication protocols such as teleportation and quantum information processing and we discus some of these new schemes including ion traps and linear optics quantum computing.