Gaussian beam superposition is applied to model representative standard transducers, which are used in aero engine disk inspection. Previously published approaches available in the literature have been applied and modified to account for rectangular and non-planar transducer apertures. Beam field calculation for both single and layered media is addressed.

This paper summarizes the theory of Fresnel diffraction by plane rectangular and circular apertures with a view toward numerical computations. Approximations found in the earlier literature, and now obsolete, have been eliminated and replaced by algorithms suitable for use on a personal computer.

A series of isostructural, noncatenated, zinc-pillared-paddlewheel metal-organic framework materials has been synthesized from 1,2,4,5-tetrakis(carboxyphenyl)benzene and trans-1,2-dipyridylethene struts. Substantial kinetic selectivity in the adsorption of propene over propane can be observed, depending on the pore apertures and the rectangular-plate morphology of the crystals.

We performed terahertz near-field experiments on single rectangular holes with various lengths grown on an electro-optic crystal substrate with lambda/100 resolution. We find that the near-field amplitude becomes proportionally larger as the rectangle becomes narrower, strongly suggesting that a constant energy passes through even for a very narrow slit. The occurrence of a large field enhancem...

This paper presents a theoretical study of stellar coronagraphy with apodized entrance apertures. The study is restricted to a perfect telescope operating in space, and a monochromatic on-axis unresolved star. It is shown that linear prolate functions are the optimal apodizers for rectangular apertures in stellar coronagraphy. With the phase mask technique (Roddier & Roddier 1997), prolate func...

Concentrating light into a nanometer domain is needed for optically based materials processing at the nanoscale. Conventional nanometer-sized apertures suffer from low light transmission, therefore poor near-field radiation. It has been suggested that ridge apertures in various shapes can provide enhanced transmission while maintaining the subwavelength optical resolution. In this work, the nea...