This is a study of elastic waves diffracted by corrugated metallic surfaces. The corrugations consist of triangular grooves with variable parameters. The results of the narrow band experiments show significant diffraction patterns depending on angle and frequency. In addition, a continuous schlieren system is used to visualize the diffracted orders. Measurements were also carried out using a br...

In this paper, a semi-analytical model is proposed to solve the diffraction problem from cylinder with moonpool. The and moonpool can be in arbitrary shapes. Linear potential flow theory eigenfunction matching method are adopted analytical model. After dividing fluid domain into three regions (i.e., region beneath cylinder; inner enclosed by exterior outer cylinder), diffracted spatial potentia...

The accuracy of depth estimation based on defocus effects has been essentially limited by the depth of field of the imaging system. We show that depth estimation can be improved significantly relative to classical methods by exploiting three-dimensional diffraction effects. We formulate the problem by using information theory analysis and present, to the best of our knowledge, a new paradigm fo...

All-reflective Michelson, Sagnac, and Fabry-Perot interferometers based on grating beam splitters are experimentally demonstrated at a wavelength of 1064 nm. A 1200-groove/mm grating diffracting 0 and -1 orders with an efficiency of 48.2% for each order was used as a near-50/50 beam splitter. The all-reflective Sagnac and Michelson interferometers were formed by reintroducing both of the diffra...

The spherical beam volume hologram, recorded by a plane wave and a spherical beam, is investigated for spectroscopic applications in detail. It is shown that both the diffracted and the transmitted beam can be used for spectroscopy when the hologram is read with a collimated beam. A new method is introduced and used for analysis of the spherical beam volume hologram that can be extended for ana...

A variable sensitivity displacement interferometer ~VSDI! used to monitor both normal and in-plane particle displacements in stress wave propagation experiments is introduced. The general system consists of two interferometers working in tandem. Normally reflected light is interfered with each of two symmetrically diffracted light beams generated by the specimen rear surface. In cases where the...

We investigate the geometric propagation and diffraction of singularities of solutions to the wave equation on manifolds with edge singularities. This class of manifolds includes, and is modelled on, the product of a smooth manifold and a cone over a compact fiber. Our main results are a general ‘diffractive’ theorem showing that the spreading of singularities at the edge only occurs along the ...

We report the development of a three view electronically scanned millimeter-wave interferometer for plasma electron density profile measurement on the H-1 heliac. The system utilizes an electronically tunable backward-wave oscillator whose output is incident on a fixed blazed diffraction grating such that sweeping the source frequency effects a spatial scan of the plasma cross section. Two diag...

In this paper, a wire mesh metallic photonic crystal is modelized as a stack of gratings of period d made of very thin infinitely metallic rods (the conductivity is assumed to be infinite) of radius a (a<<d) . This structure is illuminated by a s-polarized plane wave of wavelength lambda. First, we give the diffracted field in closed form for very large wavelengths compared to the period (lambd...