A little-used interferometric modification to the classical Hartmann optical test is being used for active optics corrections at the 6.5-m Multiple Mirror Telescope (MMT) Observatory. The technique produces compact interference spots whose positions depend on discrete wave-front phase-difference errors. A diffraction model illustrates the formation of interference spots. The limitations on wave...

We use Fraunhofer diffraction theory and meterological data to determine the nature of cloud-particle distributions and the mean particle sizes required for interpreting photographs of coronas and iridescence in mountain wave clouds. Traditional descriptions of coronas and iridescence usually explain these optical phenomena as diffraction by droplets of liquid water. Our analysis shows that the...

Although inherently a wave phenomena, diffraction can be implemented in a ray tracer by taking advantage of a combination of Geometric Diffraction Theory and the Huygens’-Fresnel Principle. In this paper we show how to implement interference and diffraction in a computationally tractable manner, while retaining the properties of the full volume integration solution.

The measurement of the acoustic pressure of a planar ultrasonic wave by light diffraction is well established. The ability to do similar measurements in the case of spherical waves has been doubted However, we show that the range of validity can be extended to the focal region of a spherical concave piezoelectric transducer. Light is passed through the focal plane of a spherical concave transdu...

Different electromagnetic theories have been applied in order to understand the interaction of the electromagnetic radiation with diffraction gratings. Kogelnik’s Coupled Wave Theory, for instance, has been applied with success to describe the diffraction properties of sinusoidal volume gratings. Nonetheless the predictions of Kogelnik’s theory deviate from the actual behaviour whenever the hol...

The Huygens-Fresnel diffraction integral has been formulated for incident spherical waves with use of the Kirchhoff obliquity factor and the wave front as the surface of integration instead of the aperture plane. Accurate numerical integration calculations were used to investigate very-near-field (a few aperture diameters or less) diffraction for the well-established case of a circular aperture...

Diffraction of multi-level atoms by an evanescent wave reflective diffraction grating is modeled by numerically solving the time-dependent Schrödinger equation. We are able to explain the diffraction observed in experiments with metastable Neon. This is not possible using a two-level atom model. The multi-level model predicts sensitive dependence of diffraction on the laser polarization and on ...

Substrate guided-wave (SGW) holograms are recorded by guiding the reference wave to the hologram using an optical substrate.1'2 As compared to conventional holographic recording systems, SGW systems are compact, portable, robust, and easy to align. Since the illuminating beam is encapsulated within the substrate and only the holographic image is diffracted, the hologram can be viewed close to t...

A linear three-dimensional problem of hydroelastic wave diffraction by a bottom-mounted circular cylinder is analysed. The fluid is of finite depth and is covered by an ice sheet, which is clamped to the cylinder surface. The ice stretches from the cylinder to infinity in all lateral directions. The hydroelastic behaviour of the ice sheet is described by linear elastic plate theory, and the flu...

We observe experimentally a novel type of nonlinear diffraction in the process of two-wave mixing on a nonlinear quadratic grating. We demonstrate that when the nonlinear grating is illuminated simultaneously by two noncollinear beams, a second-harmonic diffraction pattern is generated by a virtual beam propagating along the bisector of the two pump beams. The observed diffraction phenomena is ...