The group velocity of electromagnetic waves diffracted by a small aperture

✍ Scribed by Anthony A. Ruffa

• Publisher: Elsevier Science
• Year: 2002
• Tongue: English
• Weight: 58 KB
• Volume: 35
• Category: Article
• ISSN: 0165-2125
• DOI: 10.1016/s0165-2125(01)00088-9

✦ Synopsis

Diffraction of electromagnetic waves by an aperture in an infinite opaque screen is approached using an integral expression characterized by the spatial Fourier transform at the aperture. The group velocity of the field propagated from the aperture assumes a continuous distribution of values corresponding to the distribution in transverse wavenumber. The gravitational Doppler shift is computed for an aperture that is small compared to a wavelength. It is found that the integral expression can be evaluated analytically, leading to a distribution of Doppler shifts; the minimum Doppler shift is on the order of one part in 10 15 . Every additional order of magnitude increase in the Doppler shift results in a decrease in amplitude by two orders of magnitude.