This paper proposes a novel high-contrast grating (HCG) element that simultaneously has two distinct functions; focusing and polarizing. The phase front distribution of a diffracted wave is fitted to that of an ideal conventional lens through properly controlling only the thicknesses of each grating bar. Finally, it is confirmed that the properly designed HCG can be a polarizer as well as a len...

[1] Seismic phases diffracted around Earth’s core contain information about lowermost mantle wave speeds. By measuring the slowness of incident diffracted energy from array recordings, seismic velocity along the diffracted path can be estimated. Here we apply this principle to diffraction of the major arc seismic phase PKKPab recorded at the Canadian Yellowknife array to estimate P wave velocit...

Void detection is challenging due to the complexity of near-surface materials and the limited resolution of geophysical methods. Although multichannel, high-frequency, surface-wave techniques can provide reliable shear (S)-wave velocities in different geological settings, they are not suitable for detecting voids directly based on anomalies of the S-wave velocity because of limitations on the r...

Closed-form solutions have been derived for the diffraction patterns at the focal plane of (1) a convergent wave of unit amplitude illuminating a segment of a circular aperture and (2) a convergent wave of Gaussian amplitude diffracted by an infinite edge. Photographs showing the main features of these edge transform patterns are presented together with computer-generated graphs.

A fully analytical theory is developed to derive the field diffracted by an infinitely long circular cylinder made of an arbitrary anisotropic homogeneous material, illuminated by an arbitrary plane wave.

A mathematical model for describing a holographic coupler-optical fiber system is considered. The object wave to be recorded in the hologram is assumed to be a polarized wave which is scattered by the optical fiber. In the reconstruction the optimal condition for the diffracted wavefront to be coupled to a second fiber is obtained and numerically analyzed.

In this Letter, a collimated light acoustooptic lateral shearing interferometer (AO/LSI) capable of variable shear is described for use with either visual or ac electronic real-time phase measurements. The principle of operation of the AO/LSI is shown in Figs. 1 and 2. An input beam of diameter W is incident at Bragg’s angle upon two acoustooptic modulators (AOM’s) in series. They are shown sch...

Profiles of SH waves diffracted around the core (Sd) for three deep events at stations across North America and the Atlantic (4 = 92 ° to 152 °) are used to determine the properties of the lower mantle in the vicinity of the core-manUe boundary (CMB). The S-wave velocity above the CMB is found to be tic = 7.22 __ 0.1 km/sec, in agreement with gross earth models, but higher than previously repor...