Related papers: Spillover and diffraction sidelobe contamination i…
This paper is concerned with the diffraction of an electromagnetic wave by a perfectly conducting half-plane in a homogeneous bi-isotropic medium (asymptotically). Similar analysis in a source-free field is done in Asghar,S. and Lakhtakia,…
We used two novel approaches to produce sub-wavelength structure (SWS) anti-reflection coatings (ARC) on silicon for the millimeter and sub-millimeter (MSM) wave band: picosecond laser ablation and dicing with beveled saws. We produced…
Low wind and petaling effects, caused by the discontinuous apertures of telescopes, are poorly corrected -- if at all -- by commonly used workhorse wavefront sensors (WFSs). Wavefront petaling breaks the coherence of the point spread…
The Simons Observatory (SO) will measure the cosmic microwave background (CMB) in both temperature and polarization over a wide range of angular scales and frequencies from 27-270 GHz with unprecedented sensitivity. One technology for…
Recently a hypothesis explaining the non-resonant mechanism of subwavelength imaging granted by a dielectric microsphere has been suggested. In accordance to the hypothesis, the far-field image of a subwavelength scatterer strongly coupled…
This dissertation is concerned with understanding and analyzing some of the effects of diffraction in the near field. The contributions of homogeneous and of evanescent waves to two-dimensional near-field diffraction patterns of scalar…
(Abridged) Atmospheric dispersion and field differential refraction impose severe constraints on widefield MOS observations. Flux reduction and spectral distortions must be minimised by a careful planning of the observations -- which is…
Layered materials (LMs) are at the centre of an ever increasing research effort due to their potential use in a variety of applications. The presence of imperfections, such as bi- or multilayer areas, holes, grain boundaries, isotropic and…
Diffraction microtomography in coherent light is foreseen as a promising technique to image transparent living samples in three dimensions without staining. Contrary to conventional microscopy with incoherent light, which gives…
Next-generation centimeter to sub-millimeter telescopes require exquisite control over instrumental far-sidelobe response to accurately measure faint signals like the Cosmic Microwave Background B modes. Because existing electromagnetic…
The diffraction of a scalar plane wave from a doubly-periodic surface on which either the Dirichlet or Neumann boundary condition is imposed is studied by means of a rigorous numerical solution of the Rayleigh equation for the amplitudes of…
This work presents a wideband tri-band shared-aperture antenna array covering the 5G mid-band and 6G centimetric band. The challenge of scattering and coupling suppression is holistically addressed across the wide bands. Guided by…
LiteBIRD, a forthcoming satellite mission, aims to measure the polarization of the Cosmic Microwave Background (CMB) across the entire sky. The experiment will employ three telescopes, Transition-Edge Sensor (TES) bolometers and rotating…
Geometric environment information aids future distributed radio infrastructures in providing services, such as ultra-reliable communication, positioning, and wireless power transfer (WPT). An a priori known environment model cannot always…
With the deployment of large antenna arrays at high-frequency bands, future wireless communication systems are likely to operate in the radiative near-field (NF). Unlike far-field beam steering, NF beams can be focused on a spatial region…
When subjected to monochromatic incident light a nanoparticle will emit light which then interferes with the incident beam. With sufficient contrast and sufficiently close to the particle this interference pattern may be recorded with a…
Terahertz frequencies are an untapped resource for providing high-speed short-range communications. As a result, it is of interest to study the propagation characteristics of terahertz waves and to develop channel models. In previous work…
X-ray dark-field or ultra-small angle scatter imaging has become increasingly important since the introduction of phase-based x-ray imaging and is having transformative impact in fields such as in vivo lung imaging and explosives detection.…
Precession of a converged beam during acquisition of a 4D-STEM dataset improves strain, orientation, and phase mapping accuracy by averaging over continuous angles of illumination. Precession experiments usually rely on integrated systems,…
In this research, we report the experimental evidence of the directional Fano resonances at the scattering of a plane, linearly polarized electromagnetic wave by a homogeneous dielectric sphere with high refractive index and low losses. We…