source localization is an essential part of array signal processing including radar, sonar, seismology and oceanography applications. the performance of the presented source localization methods are degraded substantially in practical situations. one of the conditions which decreases the performance o

We present a direct, room-temperature near-field optical study of light confinement by a subwavelength defect microcavity in a photonic crystal slab containing quantum-well sources. The observations are compared with three-dimensional finite-difference time-domain calculations, and excellent agreement is found. Moreover, we use a subwavelength cavity to study the influence of a near-field probe...

A near-field optical virtual probe (NFOVP) is a type of immaterial tip based on the principle of near-field evanescent wave interference. Evanescent wave interference and the aperture type play very significant roles in generating near-field optical virtual probes. Two evanescent waves, propagating in opposite directions, will interfere to generate the confinement field. The central peak of the...

The paper presents an iterative method for the computation of the near fields of single layer microstrip patch antennas. A judicious combination of the advantages of the MPIE (mixed potential integral equation) method, the FFT algorithm and the biconjugate gradient leads to an efficient numerical solution. The scheme can deal with patches of arbitrary shapes and is capable of dealing with a ver...

In this review we describe fundamentals of scanning near-field optical microscopy with aperture probes. After the discussion of instrumentation and probe fabrication, aspects of light propagation in metal-coated, tapered optical fibers are considered. This includes transmission properties and field distributions in the vicinity of subwavelength apertures. Furthermore, the near-field optical ima...

We use fluorescent nanospheres as scalar detectors for the electric-field intensity in order to probe the near-field of an optical tip used in aperture-type near-field scanning optical microscopy (NSOM). Surprisingly, the recorded fluorescence images show two intensity lobes if the sphere diameter is smaller that the aperture diameter, as expected only in the case of vector detectors like singl...

A full characterization of the far-field noise obtained from cylindrical nearto far-field transformation, for a white Gaussian, space stationary, near-field noise is derived. A possible source for such noise is the receiver additive noise. The noise characterization is done by obtaining the autocorrelation of the far-field noise, which is shown to be easily computed during the transformation pr...

Nanoscale ridge aperture antennas have been shown to have high transmission efficiency and confined nanoscale radiation in the near field region compared with regularly-shaped apertures. The radiation enhancement is attributed to the fundamental electric-magnetic field propagating in the TE(10) mode concentrated in the gap between the ridges. This paper reports experimental demonstration of fie...

Near-field optical probe is the key element of a near-field scanning optical microscopy (NSOM) system. The key innovation in the first two NSOM experiments (Pohl et al., 1984; Lewis et al., 1984) is the fabrications of a sub-wavelength optical aperture at the apex of a sharply pointed transparent probe tip with a thin metal coating. This paper discusses the routine use of focussed ion beam (FIB...

The near-horizon properties of a black hole are studied within an algebraic framework, using a scalar field as a simple probe to analyze the geometry. The operator H governing the near-horizon dynamics of the scalar field contains an inverse square interaction term. It is shown that the operators appearing in the corresponding algebraic description belong to the representation space of the Vira...