Eur. Phys. J. D (2015) 69: 44
https://doi.org/10.1140/epjd/e2014-50693-1

Regular Article

The quantum optical description of three experiments involving non-linear optics using a graphical method

ECE Paris, 37 Quai de Grenelle, Batiment Pollux, 75015 Paris, France

^a e-mail: ataman@ece.fr

Received: 21 September 2014
Received in final form: 8 December 2014
Published online: 12 February 2015

Abstract

In this paper we describe and thoroughly discuss three reported experiments in quantum optics (QO) involving interferometers and non-linear crystals. We show that by using a graphical method and an over-simplified model of the parametric down-conversion process, we arrive to explain all the important results reported in the respective papers. Indistinguishability is discussed in the case of separable/non-separable (i.e. entangled) quantum systems and our interpretation is sometimes at variance with the one given by the authors reporting the experiments.