The study of the interaction between electromagnetic waves and matter in cavity atomic systems is at the heart of many developments such as atom-field entanglement and the development of atomic memories

The study of the interaction between electromagnetic waves and matter in cavity atomic
systems is at the heart of many developments such as atom-field entanglement and the
development of atomic memories . These phenomena have been observed in the situation
of strong coupling between the photons and atoms in the cavity . Such a system offers
fascinating nonclassical features of light: saueezing and antibunching. The first occurs when
some noise component in the field is below the standard quantum limit and the second
corresponds to a light with photons more equally spaced than a coherent field. These
concepts have been revisited in the field of condensed matter thanks to the development of
new growth technologies for semiconductor heterostructures.In semiconductor structures, fundamental excitation is composed of an electron and a hole bound by Coulomb interaction, forming an exciton. This particle can be created by the absorption of one or more photons
and may become excited radiatively. This exciton interacts with photons which themselves
can be confined in a cavity. By confining excitons and photons in one system, it is possible
to increase their mutual interactions and observe the regime of strong coupling, where the
interaction gives rise to a quasi-particle called polariton. The polariton is composed of a
photonic part, the photon of the cavity, and an excitonic part; it is therefore both light and
matter. Semiconductor microcavities in strong coupling regime have been since the subject
of intense research