The Arago–Poisson Spot: New Applications for an Old Concept

Abstract

Herein, we report some specific properties and applications of the so-called Arago–Poisson spot in optics. This spot results from the diffraction of a plane wave by an occulting disk that leads to a small bright spot in its shadow. We discuss some of the properties of such beams. In particular, we focus on the ultimate size that can be reached for these beams, which depends on the diameter of the disk, the wavelength, and the distance from the disk. We also highlight self-healing and faster-than-light properties. Applications are then proposed. The applications mainly deal with new traps with nanometer sizes dedicated to the trapping of nanoparticles. We also discuss beams that change frequency during propagation and their application for signal delivery in a precise and determined area.