A semiclassical optics derivation of Einstein's rate equations Am. J. Phys. 80, 882 (2012) On energy transfers in reflection of light by a moving mirror Am. J. Phys. 80, 684 (2012) Analysis of light scattered by a capillary to measure a liquid's index of refraction Am. J. Phys. 80, 688 (2012) Cavity quantum electrodynamics of a two-level atom with modulated fields Am.An optical vortex is a screw dislocation in a light field that carries quantized orbital angular momentum and, due to cancellations of the twisting along the propagation axis, experiences zero intensity at its center. When viewed in a perpendicular plane along the propagation axis, the vortex appears as a dark region in the center surrounded by a bright concentric ring of light. We give detailed instructions for generating optical vortices and optical vortex structures by computer-generated holograms and describe various methods for manipulating the resulting structures.

We show that a laser beam which propagates through a cubic-quintic nonlinear optical material may reach, for a given power, a condensed state with a collisional dynamics resembling a liquid drop. We qualitatively describe the analogies between this system and the usual fluids and show them by simulating numerically total reflections of these beams with planar boundaries and localized defects. We use the analogy "liquid light" to stress the connections with the dynamics of quantum fluids, including Bose-Einstein condensates.

Metal Halide Perovskites (MHPs) have arisen as promising materials to construct cost-effective photovoltaic and light emission devices. The study of nonlinear optical properties of MHPs is necessary to get similar success in nonlinear photonic devices, which is practically absent in the literature. The determination of the third order nonlinear coefficients is typically done by the Z-scan technique, which is limited by the scattering of polycrystalline thin films. In this work, we have studied nonlinear optical properties of polycrystalline CH3NH3PbX3 (MAPbX3) thin films and colloidal CsPbX3 nanoparticles with three different bandgaps (X3 = I3, Br3, and Br1.5I1.5). Their bright generation of photoluminescence under infrared illumination demonstrates an excellent efficiency of multiphoton absorption. The nonlinear absorption coefficient (β) was studied by analyzing the transmitted light through the samples, observing the expected Eg−3 dependence with values as high as β = 1500 cm/GW. In addition, we proposed the use of a modified Z-scan technique with imaging processing to analyze the nonlinear refraction coefficient (n2) under the laser damage threshold. Our experimental data agree quite well with theoretical predictions, demonstrating the accuracy of the method and potential applications to other thin films. Moreover, n2 parameter reaches values of 3.5 cm2/GW, indicating the suitability of MHPs for nonlinear photonics.

The zone plates ͑diffractive lenses͒ are not commonly used as image formation systems owing to their low efficiency and multifocal characteristics. In this paper we make a revision of the Fresnel zone plate principles, and present various kinds of zone plates designed to solve the problem of obtaining a limited number of foci with higher efficiency. The purpose of this work was to design, by using Fermat's principle, a zone-plate profile with high focusing efficiency in only one or two foci, while maintaining a low efficiency in the others. Applying Fermat's principle to this task results in the kinoform profile of the plate. Calculation of the kinoform profile efficiency reveals that it is the best possible solution to this problem. ©

A study on the nonlinear modes of plasmonic directional couplers created by two nonlinear dielectric slot waveguides with metallic claddings is presented. The calculated power diagram shows substantial differences from the case of nonlinear dielectric couplers. The power-dependent switching and the effect of losses on the coupler performance are studied using finite-difference time-domain numerical simulations.