Nonlinear diffuse reflection and transmission of radiative energy by a layer of finite thickness

V.M. Agranovich, С. А. Киселев, D. L. Mills

We consider the theory of transmission of electromagnetic radiation through a superlattice of finite length, in which the size of the unit cell is small compared to an optical wavelength. One film in each unit cell is assumed to exhibit an optical nonlinearity of Kerr form. We show that a slow spatial modulation of the thickness of the layers leads to a structure with a low threshold for optical bistability.

Nikolay N. Rosanov

Dmitrii I. Sementsov, В. В. Ефимов

The interference of two opposing coherent waves in a thin layer was studied. Expressions for energy fluxes outside and inside the layer are obtained for normal incidence. It is shown that the interference flux, whose magnitude and direction vary markedly with layer parameters, amplitude and phase of incident waves may be derived together with incident, transmitted and reflected wave fluxes. The distribution of the total energy flux by thickness inside absorbing and amplifying layers was examined for single incident wave. The dependence of transmission and reflection energy coefficients, T and R, on the thickness of a layer with negative absorption has been studied numerically in detail for the case of normal incidence.

M. B. Gornyi, D. L. Markman, Boris G. Matisov

Zai-Cheng Xiao, Li-Ping Yang

Two-dimensional atomic arrays provide versatile free-space quantum optical interfaces by coupling photons to collective lattice modes. Here we show that the Rayleigh--Wood anomaly provides a sharp control mechanism for both linear and nonlinear photon scattering from a single atomic layer. As the lattice spacing crosses the diffraction threshold, newly opened radiative channels rapidly broaden the dominant collective modes, converting specular reflection into diffuse off-axis scattering. In transmission, momentum-space Fano interference between the incident and collectively scattered fields produces single-photon intensity zeros that strongly reshape the momentum-space correlation pattern. An integrated nonlinear contrast reveals a pronounced channel asymmetry: upon opening the Rayleigh channels, the connected two-photon contribution drops by several orders of magnitude relative to the factorized background in transmission, while remaining close to unity in reflection. These results establish radiative diffraction thresholds as a control principle for quantum nonlinear optics in single-layer atomic arrays.

B. A. Veklenko, Ganna Tkachuk