Dressed Photons

Gabriel Molina‐Terriza, Juan P. Torres, Lluís Torner

Suguru Sangu, Hayato Saigo

Several interesting physical phenomena and industrial applications explained by the dressed photon have been reported in recent years. These require a novel concept in an off-shell science that deviates from the conventional optics, satisfying energy and momentum conservation laws. In this paper, starting from an original model that captures dressed-photon characteristics phenomenologically, the dynamics of the dressed photon in a nanomatter system and the mechanism for extracting internal degrees of freedom of the dressed photon to an external space have been examined by theoretical and numerical approaches. Our proposal is that basis states of the dressed photon can be transformed to the form that reflects the spatial distribution of the dressed-photon steady state in the system, and some of basis states with predetermined spatial distribution can relate to the dissipation components in the external space by means of the renormalization technique. From the results of numerical simulation, it is found that quasi-static states are regarded as the photon with light mass or massless, and the extraction of active states strongly affects the spatial distribution in a new steady state. The concept for extracting dressed-photon energy to an external space will contribute to a detailed understanding of dressed-photon physics and future industrial applications.

Ze Cheng

Bose–Einstein condensation (BEC) of dressed photons in a Kerr nonlinear optical microcavity is investigated. Our experimental scheme is based on an optical microcavity filled with a Kerr nonlinear nonpolar crystal. The pump photons interact with the Raman phonons in the crystal and hence are converted into new quasiparticles, which we refer to as dressed photons. A dressed photon is a photon dressed with a cloud of virtual transverse-optical phonons. The first main finding is that two-dimensional (2D) dressed photons have an increased inert mass. The second main finding is that the lower cutoff frequency of a nonlinear optical microcavity becomes larger. The third main finding is that the incident laser intensity is a moderate laser intensity ([Formula: see text]10[Formula: see text] W/cm2). The fourth main finding is that the critical optical power of a nonlinear optical microcavity is increased. The fifth main finding is that the radiation emitted by 2D dressed photons has an ultrahigh intensity.

Motoichi Ohtsu

Luca Leonforte, Angelo C. M. Carollo, Francesco Ciccarello

We identify a class of dressed atom-photon states forming at the same energy of the atom at any coupling strength. As a hallmark, their photonic component is an eigenstate of the bare photonic bath with a vacancy in place of the atom. The picture accommodates waveguide-QED phenomena where atoms behave as perfect mirrors, connecting in particular dressed bound states (BSs) in the continuum with geometrically confined photonic modes. When applied to photonic lattices, the framework establishes a one-to-one correspondence between topologically robust dressed states and topologically robust photonic BSs seeded by a vacancy. This is used to predict new classes of dressed BSs in the photonic Creutz-ladder and Haldane models. In the latter case, states with nonzero local photon flux occur in which an atom is dressed by a photon orbiting around it.

M. Bertolotti