Light by light diffraction in vacuum

Negative refraction of light by vacuum

Propagation of electromagnetic plane waves in some directions in gravitationally affected vacuum over limited ranges of spacetime can be such that the phase velocity vector casts a negative projection on the time–averaged Poynting vector. This conclusion suggests, inter alia, gravitationally assisted negative refraction by vacuum.

Light bullets by synthetic diffraction-dispersion matching.

We put forward a new approach to generate stable, fully three-dimensional light bullets, which is based on the matching of the intrinsic material dispersion with a suitable effective diffraction. The matching is achieved in adequate waveguide arrays whose refractive index is periodically modulated along the direction of light propagation. We show that by using nonconventional, out-of-phase long...

Fraunhofer diffraction of light by human enamel.

Fraunhofer diffraction patterns of human enamel samples were photographed with a helium-neon laser beam (lambda = 633 nm). The first-order diffraction angle was in reasonable agreement with a prediction based upon enamel prisms acting as a two-dimensional grating. These results support the hypothesis that enamel diffracts light because of the periodic structure of enamel prisms with interprisma...

Light diffraction by a subwavelength circular aperture

Diffraction of normally incident light by a subwavelength circular aperture is calculated analytically. The aperture is opened on a perfectly conducting planar screen with infinitesimal thickness. In our model, the aperture is replaced by uniform magnetic currents and charges. The model allows one to obtain the normalized cross section for the aperture radius up to half of the wavelength, which...

Light Diffraction by Single Striated Muscle Fibers