Laser Nano-Fields For Atom Optics
1. Nano-fields with the Fresnel hole
Laser light incident from the left on a conductive screen with a circular aperture of radius a is about of the light wavelength (the Fresnel hole). The figure shows the electric energy as a function of transverse coordinates. The characterictic features of the field is smaller than the wavelength [1].
Electric field energy density for the Fresnel hole at distance z=0.5a (a is a radius of the hole) |
Electric field energy density for the Fresnel hole at distance z=a (a is a radius of the hole) |
Electric field energy density for the Fresnel hole at distance z=5a (a is a radius of the hole) |
2. The Bethe hole
Laser light incident from the left on a conductive screen with a circular aperture radius a is smaller than the light wavelength (the Bethe hole). The figure shows the electric density as a function of transverse coordinates. The characterictic features of the field is considerably smaller than the wavelength [1,2].
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Electric field energy density in the case of incidence of circularly polarized light wave for the Bethe hole at distance z=0.05a (a is a radius of the hole) |
Electric field energy density in the case of incidence of circularly polarized light wave for the Bethe hole at distance z=0.1a (a is a radius of the hole) |
Electric field energy density in the case of incidence of circularly polarized light wave for the Bethe hole at distance z=0.5a (a is a radius of the hole) |
3. The photon hole
Two plane conductive plates spaced at a distance d of the order of or smaller than the wavelength of light apart form a plane waveguide for the laser light coupled into it from one side. If the electric field vector of the laser light is normal to the plane of the waveguide, the light can propagate through the waveguide, no matter how thick it is. Two small coaxial apertures is made in the conductive screens. If the diameters of these apertures are less than the wavelength of the light coupled into the waveguide, small part of the light escapes from the waveguide through the apertures, but the light field near them is strongly modified. There is a light field intensity minimum in the direction normal to the plane of the waveguide. Such a field configuration may be called a photon hole. Its characteristic size is determined by the size of the apertures, the thickness of the waveguide and its volume V << λ3 [3].
Electromagnetic-field intensity for a photon hole with a/d = 1.
4. The photon dot
Two conductive screens with coaxial apertures are spaced a distance of d = λ /2 apart and the electric field strength vector is parallel to the waveguide plane. The intensity distribution in such a light field is presented in Figure. The field drops off rapidly outside the waveguide in the direction normal to the waveguide and has its maximum at the center of the waveguide. Such a light field configuration occupy volume V << λ3 can be called a photon dot [3].
Electromagnetic field intensity for a photon dot with a/d = 0.5
