Near-field electromagnetic “emission

Low-frequency electromagnetic waves (RE—for radiowave emission) were detected with coil antennas placed a few mm from the sample. Such an antenna couples to a changing B field. It should be emphasized that this arrangement detects the near-field electromagnetic emission because of the close proximity of the coils to the source. A simultaneous burst of visible photons coincident with the observed RE burst reinforces the interpretation that these signals are caused by microdischarges. 

RE is usually detected with a coil antenna, with or without a ferrite core, placed near the sample. This antenna couples to the changing B fields associated with electromagnetic emissions. RE is especially interesting, as it is often associated with electrical discharges within the crack and on the fracture surfaces. 

The electromagnetic nature of surface-enhanced Raman scattering (SERS) and plasmon-enhanced fluorescence (PEF) involves resonant excitations of localized plasmons (LPs) in the near-field of nanosized noble metal particles or films, coupling them with surrounding scatterers and detection of their secondary emission in the far field. Employment of these plasmonic phenomena are proposed, for example, as a new approach to increase brightness of heavily labeled macromolecules [1]. 

Several electromagnetic lenses the first lenses (or first lens in the case of a field emission microscope), known as ""condensers", reduce the size of the source. The last, so-called objective", lens, positioned near the sample, focuses the probe onto the specimen. 

Classical and quantum treatments of electromagnetic fields [7], near a plane dielectric interface, show that the probability of photo-ionization or photo-excitation of an atom exhibits a pronounced peak at the critical angle of incidence of a plane wave propagating in the dense medium. The probability of absorption or emission of a photon is proportional to the photometric intensity of the electromagnetic field. In particular, consider a plane wave propagating in the dense medium with refractive index /2i, at angle of incidence Ox. The intensity of the transmitted field at a distance dy from the interface is given by... 

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