Physical optics

About: Physical optics is a research topic. Over the lifetime, 5342 publications have been published within this topic receiving 101388 citations. The topic is also known as: wave optics.

Reflection dyadic for the soft and hard surface with application to the depolarising corner reflector

Abstract: Applying scalarisation of the plane-wave fields, an expression for the reflection dyadic corresponding to the soft and hard surface (SHS) is derived, applicable for both the electric and magnetic fields of the plane wave. Eigenvectors and eigenvalues of the reflection dyadic allow one to express the dyadic in a particularly simple form in terms of circularly polarised unit vectors. The expression can be effectively applied to problems involving consecutive reflections from many SHS surfaces. As an example, reflection of a plane wave from a corner reflector involving three SHS faces is studied. The total reflection dyadic has a simple form showing that the handedness of a circularly polarised wave is not changed in the reflection. The reflection phase angle of rays after different reflection paths is given a simple formula readily applicable for a physical optics analysis of the totally corrugated corner reflector.

A radio-coverage prediction model in wireless communication systems based on physical optics and the physical theory of diffraction [Wireless Corner]

Abstract: In this paper, a two-dimensional (2D) simulation method for the calculation of radio coverage in urban-area sites is presented, based on the analytical methods of physical optics (PO) and the physical theory of diffraction (PTD). The method takes into account the electromagnetic field at the receiving antenna due to first- and higher-order propagation mechanisms. Emphasis is given on the computation of the scattered near or Fresnel-zone field using numerical techniques, since in a typical urban environment, the scattered near or Fresnel-zone field occupies a large percentage of the area under investigation. The high resolution radio-coverage plots are computed by complex vector addition of all of the received signals for several values of the channel parameters. Finally, a comparison of the radio-coverage results obtained through this method with the corresponding results based on different electromagnetic methods and measurements, previously published in the literature, is presented.

Experimental demonstration of an intensity minimum at the focus of a laser beam created by spatial coherence: application to the optical trapping of dielectric particles

Abstract: In trying to manipulate the intensity distribution of a focused field, one typically uses amplitude or phase masks. Here we explore an approach, namely, varying the state of spatial coherence of the incident field. We experimentally demonstrate that the focusing of a Bessel-correlated beam produces an intensity minimum at the geometric focus rather than a maximum. By varying the spatial coherence width of the field, which can be achieved by merely changing the size of an iris, it is possible to change this minimum into a maximum in a continuous manner. This method can be used, for example, in novel optical trapping schemes, to selectively manipulate particles with either a low or high index of refraction.

Design of an ultra-broadband V antenna for microwave detection of breast tumors

Abstract: sEarr s Egrp s where Earr and Egrp are the fields scattered from the array of microstrip patches and from the finite ground plane, respectively. The first term is computed with the use of the MoM code, and the second is evaluated with the physical optics theory. The results given by this method (crossed curve) are in good agreement with the measured ones. 3. CONCLUSIONS In this Letter an experimental analysis of the phase of the scattered field from a patch embedded in an array environment has been presented. An hybrid moment method—physical optics technique has been proved to be an effective method of analysis with a reduced computational effort. This approach permits the phase relation to be calculated by a standard commercial full wave code, saving a large amount of computational time.