The optical transmission through a subwavelength aperture in a metal film is strongly enhanced when the incident light is resonant with surface plasmons at the corrugated metal surface surrounding the aperture. Conversely, the aperture acts as a novel probe of the surface plasmons, yielding useful insights for optimizing the transmission enhancement. For the optimal corrugation geometry, a set ...

Many high-energy lasers (HELs) have noncircular output apertures. Some are rectangular in shape with or without a central or noncentral (up to 30%) obscuration. However, most high-energy laser propagation codes (especially those developed for systems analysis) model the aperture as either an unobscured circle or as a circle with fixed (e.g., 10%) obscuration. We present a beam-quality/aperture-...

The main purpose of this paper is to develop the method of characteristic functions for calculating the detection characteristics in the case of the object surrounded by rough surfaces. This method is to be implemented in synthetic aperture radar (SAR) systems using optimal resolution algorithms. By applying the specified technique, the expressions have been obtained for the false alarm and cor...

Across two experiments, this study found that the barber pole illusion (i.e. grating pattern appearing to move in the direction of the long axis of a rectangular aperture) is perceived with stereoscopic (cyclopean) motion. The grating and aperture comprising the barber pole display were created from binocular disparity differences embedded in a dynamic random-dot stereogram or from luminance di...

1 Work supported by the U.S. Department of Energy * [email protected] Abstract One of the straightforward ways towards the higher luminosity in the LHC is a replacement of the present 70mm NbTi quadrupoles with Nb3Sn quadrupoles which would provide the same field gradient but in a larger aperture. Conceptual designs of such magnets with 90 mm aperture have been developed and studied. This paper d...

A crucial issue in coherent x-ray diffraction imaging experiments is how to increase the signal-to-noise ratio when measuring relatively weak diffraction intensities from a nonperiodic object. A novel crystal guard aperture is described that makes use of a pair of multiple-bounce crystal optics to eliminate unwanted parasitic scattering background. This background is often produced by upstream ...

The "just noticeable difference" (JND) represents the minimum amount by which a stimulus must change to produce a noticeable variation in one's perceptual experience (i.e., Weber's law). Recent work has shown that within-participant standard deviations of grip aperture (i.e., JNDs) increase linearly with increasing object size during the early, but not the late, stages of goal-directed grasping...

This paper considers the higher-order scattered and transmitted wave fields that result when an acoustic wave from a point source impinges at an arbitrary angle on a rectangular aperture in a rigid, thick wall. In this analysis, it is assumed that free field conditions exist on both sides of the aperture. Although the full scattered and transmitted pressure fields contain both modal sum and mod...

The spectrum of the Dirichlet Laplacian on conical layers is analysed through two aspects: the infiniteness of the discrete eigenvalues and their expansions in the small aperture limit. On the one hand, we prove that, for any aperture, the eigenvalues accumulate below the threshold of the essential spectrum: For a small distance from the essential spectrum, the number of eigenvalues farther fro...

University of Illinois, USA We will report the design and performance of a MR-compatible SPECT system that utilizes a dual-FOV aperture design for microscopic SPECT imaging of small animals inside an pre-existing MR scanner. The MRC-SPECT-DF system consists of a full ring of high resolution CdTe detectors and an aperture that consists of dual-FOV aperture system design that has two sets of aper...