A scanning near-field optical microscope (SNOM) is a powerful tool to investigate optical effects that are smaller than Abbe’s limit. Its greatest strength is the simultaneous measurement of high-resolution topography and optical near-field data that can be correlated to each other. However, the resolution of an aperture SNOM is always limited by the probe. It is a technical challenge to fabric...

current research, that involves laboratory investigations into the phenomena of solubility, uses circulation equipment that has been developed to study the enlargement of joint aperture. this paper describes the preliminary results of laboratory experiments on ten different length and width of samples, which show that the flow rate through the fissures increases with time as the fissures enlarg...

Recent evidence suggests that normal aging is typically accompanied by impairment in the ability to perceive the global (overall) motion of visual objects in the world. The purpose of this study was to examine the interplay between age-related changes in the ability to perceive translational global motion (up vs. down) and important factors such as the spatial extent (size) over which movement ...

We study the interpixel cross talk introduced to digital holographic data storage by use of a multilevel phase mask at the data-input plane. We evaluate numerically the intensity distribution at the output detector for Fourier plane hologram storage in a limited-aperture storage medium. Only the effect at an output pixel of interpixel cross talk from the four horizontal and vertical neighboring...

Irradiance fluctuations of an infrared laser beam from a shore-to-ship data link ranging from 5.1 to 17.8 km are compared to lognormal (LN), gamma-gamma (GG) with aperture averaging, and gamma-Laguerre (GL) distributions. From our data analysis, the LN and GG probability density function (PDF) models were generally in good agreement in near-weak to moderate fluctuations. This was also true in m...

The use of synchrotron radiation ~SR! as a farand mid-infrared source in the measurement of photoacoustic Fourier transform infrared spectra of solids is demonstrated for the first time in this work. Initial experiments were performed at beamline U10A at the National Synchrotron Light Source, Brookhaven National Laboratory. For synchrotron photoacoustic spectroscopy to be feasible, it must yiel...

A system of two probes is designed for terahertz (THz) time-domain spectroscopy of sub-wavelength size objects. A twin-needle probe confines broadband THz pulses spatially by means of surface plasmon waves to a sub-wavelength spot smaller than 10 microns. The confined pulses are detected within the near-field zone of the twin-needle probe by a sub-wavelength aperture probe. The system allows TH...

The feed for reflectarrays and transmitarrays is crucial determining the overall antenna aperture efficiency, gain, power handling. In past, several methods, such as altering horn shape to achieve higher modes, have been employed modify radiation pattern improve these key parameters. However, another approach use gradient index (GRIN) lenses, which offer unprecedented control over can be used s...

Scattering from man-made objects in SAR imagery exhibits aspect and frequency dependencies which are not well modeled by standard SAR imaging techniques. If ignored, these deviations will reduce recognition performance due to the model mismatch, but when appropriately accounted for, these deviations from the ideal point scattering model can be exploited as attributes to better distinguish scatt...

The active control of an incident sound field with an array of secondary sources is a fundamental problem in active control. In this paper the optimal performance of an infinite array of secondary sources in controlling a plane incident sound wave is first considered in free space. An analytic solution for normal incidence plane waves is presented, indicating a clear cut-off frequency for good ...