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V. Klimov

Publications and source records attributed to V. Klimov.

2 recordsLinked to original sources

Spatial Fano resonance of a dielectric microsphere impinged by a Bessel beam

General concept of Fano resonance is considered so that to show the possibility of this resonance in space. Using a recently found solution for a Bessel wave beam impinging a dielectric sphere, we analyze the electromagnetic fields near a microsphere with different optical size and permittivity values. We theoretically reveal a spatial Fano resonance when a resonant mode of the sphere interferes with {an amount of } non-resonant modes. This resonance results in a giant jump of the electric field behind the sphere impinged by the first-order Bessel beam. The local minimum of the electromagnetic field turns out to be noticeably distanced from the rear edge of the microsphere. However, this is a near-field effect and we prove it. We also show that this effect can be utilized for engineering a submicron optical trap with unusual and useful properties.

physics.optics

Subwavelength effects near a dielectric microcylinder illuminated by a diffraction-free beam

Generation of a photonic nanojet by a linearly polarized wave beam or a plane wave impinging a dielectric microcylinder implies partial conversion of the propagating waves into the evanescent ones. This conversion is manifested in nanojet waist of subwavelength effective width. However, this known near-field effect is relatively weak. We theoretically show that the incidence of a wave beam formed by two plane waves enables much stronger near-field effects: a deeply subwavelength focusing of the incident beam and a strong enhancement of the electric field on the whole cylinder surface and near it. The domination of the evanescent waves in the vicinity of the cylinder results from the destructive interference of the propagating spatial harmonics of the scattered field dictated by the incident wave beam.

physics.optics