Three-dimensional subwavelength confinement of light with dielectric microspheres

Abstract

International audienceDielectric microspheres are shown to be capable of confining light in a three-dimensional region of subwavelength dimensions when they are illuminated by tightly focused Gaussian beams. We show that a simple configuration, not involving resonances, permits one to reach an effective volume as small as 0.6 (l/n)3. It is shown that this three-dimensional confinement arises from interferences between the field scattered by the sphere and the high angular components of the incident Gaussian beam passing aside the sphere