Electromagnetic approach

The general description of electromagnetic waves is based on Maxwell s equations. For applications in optics, as that is important here, they reduce to the special case of charge- and current-free media. A subset of the solutions of the Maxwell equations can be assumed to be a harmonic wave of the form  

In the case of a planar waveguide with z as the direction of light propagation, the solutions to these equations can be described in the following form  

As stated earlier, the direction of light propagation is z, and the confinement of the waveguide is in the x-direction. It is assumed that the waveguide is not structured laterally, i.e., has an infinite extension in the y-direction. Then, without 

Inserting this boundary condition into (21)-(26) yields for TE  

To illustrate these results, Fig. 4 shows an example for a normalized field distribution Hy for a TM mode with index 0. 

---

Due to the symmetry constraints in a 2D electron system with a periodically modulated electron density, one can anticipate that strong chromatic conversion of the EW polarization will occur due to resonant coupling between the EW and plasma oscillations even without dc magnetic field applied. The theory of EW polarization conversion in the 2D electron system with a rectangular electron density profile was developed within the first principles electromagnetic approach... 

Scattering by an Isotmpic Particle—Extension to a Collection of Isotropic Independent Particles (Electromagnetic Approach). An electromagnetic wave interacting with matter and generating an electric field (E) can... 

In terms of their optical properties, a prominent feature of cholesterics is the helical stmcture of their director axes. Such helicity gives rise to selective reflection and transmission of circularly polarized fight. These processes may be quantitatively analyzed, using the electromagnetic approach given in the next section and in Chapter 7. We begin here with some general observations. 

As we mentioned in the beginning of the chapter, in the electromagnetic approach to nonhnear optics, the nonlinear response of a medium to an applied electromagnetic field is described by a functional dependence of the form... 

This paper compares experimental data for aluminium and steel specimens with two methods of solving the forward problem in the thin-skin regime. The first approach is a 3D Finite Element / Boundary Integral Element method (TRIFOU) developed by EDF/RD Division (France). The second approach is specialised for the treatment of surface cracks in the thin-skin regime developed by the University of Surrey (England). In the thin-skin regime, the electromagnetic skin-depth is small compared with the depth of the crack. Such conditions are common in tests on steels and sometimes on aluminium. 

In this section we consider electromagnetic dispersion forces between macroscopic objects. There are two approaches to this problem in the first, microscopic model, one assumes pairwise additivity of the dispersion attraction between molecules from Eq. VI-15. This is best for surfaces that are near one another. The macroscopic approach considers the objects as continuous media having a dielectric response to electromagnetic radiation that can be measured through spectroscopic evaluation of the material. In this analysis, the retardation of the electromagnetic response from surfaces that are not in close proximity can be addressed. A more detailed derivation of these expressions is given in references such as the treatise by Russel et al. [3] here we limit ourselves to a brief physical description of the phenomenon. 

Electromagnetic flow meters ate avadable with various liner and electrode materials. Liner and electrode selection is governed by the corrosion characteristics of the Hquid. Eor corrosive chemicals, fluoropolymer or ceramic liners and noble metal electrodes are commonly used polyurethane or mbber and stainless steel electrodes are often used for abrasive slurries. Some fluids tend to form an insulating coating on the electrodes introducing errors or loss of signal. To overcome this problem, specially shaped electrodes are avadable that extend into the flow stream and tend to self-clean. In another approach, the electrodes are periodically vibrated at ultrasonic frequencies. 

A second approach to the production of weapons material was the uranium electromagnetic separation process, based on research at the University... 

The radiation from a blackbody is conhnuous over the electromagnetic spectrum. The use of the term black in blackbody, which implies a particular color, is quite misleading, as a number of nonblack maferials approach blackbodies in behavior. The sun behaves almost like a blackbody snow radiates in the infrared nearly as a blackbody. At some wavelengths, water... 

All these multifarious activities took a lot of Einstein s energies but did not keep him from his physics research. In 1922 he published Ins first paper on unified field theoiy, an attempt at incorporating not only gravitation but also electromagnetism into a new world geometry, a subject that was his main concern until the end of his life. He tried many approaches none of them have worked out. In 1924 he published three papers on quantum statistical mechanics, which include his discoveiy of so-called Bose-Einstein condensation. This was his last contribution to physics that may be called seminal. He did continue to publish all through his later years, however. 

As the frequency of the incident electromagnetic radiation approaches that of die transition n m, the first term in the brackets of Eq. (86) dominates it... 

In LEIS, which is conceptually quite similar to PES, the sample is irradiated with a monochromatic electromagnetic radiation (e.g., a laser). Thus, it is possible to excite electrons from the sample to energy levels approaching or even surpassing the ionization barrier [94], The difference between LEIS and RIS is the mechanism... 

Barnes JD, Cardoso-Vilhena J (1996) Interaction between electromagnetic radiation and the plant cuticle. In Kerstiens G (ed) Plant cuticles an integrated functional approach. BIOS Scientific Publishers, Oxford UK, chap 7... 

---