Radiation near-infrared

Luminescence can be defined as the emission of light (intended in the broader sense of ultraviolet, visible, or near infrared radiation) by electronic excited states of atoms or molecules. Luminescence is an important phenomenon from a basic viewpoint (e.g., for monitoring excited state behavior) [1] as well as for applications (lasers, displays, sensors, etc.) [2,3]. 

Burke, A. et al. (2009) Long-term survival following a single treatment of kidney tumors with multiwalled carbon nanotubes and near-infrared radiation. Proceedings of the National Academy... 

A. Photoluminescence An excited state is produced by the absorption of ultraviolet, visible, or near-infrared radiation... 

Chemiluminescence (CL) is the emission of the electromagnetic (ultraviolet, visible, or near infrared) radiation by molecules or atoms resulting from a transition from an electronically excited state to a lower state (usually the ground state) in which the excited state is produced in a chemical reaction. The CL phenomenon is relatively uncommon because, in most chemical reactions, excited molecules... 

Phototherapy is the use of ultraviolet, visible white light or near-infrared radiation, to treat a variety of diseases... 

Photochemistry is the branch of chemistry that deals with the causes and courses of chemical deactivation processes of electronically excited particles, usually with the participation of ultraviolet, visible, or near-infrared radiation [1]. The photochemist is interested in both the modes of excited-state formation processes (direct photoexcitation, energy transfer, etc.) and the deactivation pathways of excited atoms, molecules, and ions. 

The photograph presented in Figure 13.10 shows a typical interface used to collect these noninvasive spectra. Light is incident on one side of the skinfold and a fraction of the transmitted light is collected directly from across the input fiber. Bundles of low-hydroxy silica fibers are used to deliver and collect the near-infrared radiation for the measurement. For the experiments described here, the noninvasive spectra were collected with a Fourier transform spectrometer set for a resolution of 16 cm-1 and 128 coadded interferograms. Each recorded spectrum required approximately 60 s to acquire and save. A total of 370 spectra were collected over a period of nearly 7h while in vivo glucose concentrations varied from 6 to 33 mM (108-594 mg/dL). 

M in concentration. This is in the range required for single-molecule detection. These sensitivity levels have been obtained on colloidal clusters at near-infrared excitation. Figure 10.3 is a schematic representation of a single-molecule experiment performed in a gold or silver colloidal solution. The analyte is provided as a solution at concentrations smaller than 10-11 M, Table 10.1 lists the anti-Stokes/Stokes intensity ratios for crystal violet (CY) at 1174 cm-1 using 830-nm near-infrared radiation well away from the resonance absorption of CY with a power of 106 W/cm2 [34]. CV is attached to various colloidal clusters as indicated in the table. Raman cross sections of 10-16 cm2/molecule or an enhancement factor of 1014 can be inferred from the data. 

Evaluation of A Energy separations between resolved 3d orbital energy levels correspond to visible and near-infrared radiation. Measurements of absorption spectra of transition metal compounds and minerals are used to obtain A and to evaluate the CFSE of the ions. Crystal field splittings may also be estimated from plots of thermodynamic data for the first-series transition metal compounds. The magnitude of A depends on ... 

The question was whether we could effectively shift the absorption spectrum of HABI by synthetic means or by addition of sensitizing dyes. Both approaches showed promise. Ultimately, we found the synthetic approach was more effective but many years later, when we sought to form images with near-infrared radiation, we had to depend on sensitizing dyes to shift the absorption. 

LiNb03 possesses a useful combination of piezoelectric and electro-optical properties that enable the development of devices using visible or near-infrared radiation for the logical processing of information and the routing of channels in telecommunications (see Section 8.3.5). 

The excited 02 states are singlets (xAg, g), the first of which is relatively low lying (94 kJ mol-1, equivalent to near-infrared radiation at 1270 nm) and thus can be easily populated by the energy transfer from the triplet states of most dyes the second 02 singlet 0Xg), is more difficult to reach (157 kJ mol-1), but is much more reactive. The first step of this photo-oxidation pathway is usually the singlet oxygen attack on the reactant molecule in its ground state ... 

One of the most damaging findings was the discovery that infrared radiation is not chemically active. Near infrared radiation, by the calculations of the third postulate, was supposed to be the effective radiation, but even if one could obtain this radiation in sufficient intensity it develops that no chemical reaction would result. 

Mercury-xenon lamp (Arc) An intense source of ultraviolet, visible, and near infrared radiation produced by an electrical discharge in a mixture of mercury vapor and xenon under high pressure. 

There is a real chance of a breakthrough of Raman spectroscopy in routine analytics. Excitation of Raman spectra by near-infrared radiation and recording with interferometers, followed by the Fourier transformation of the interferogram into a spectrum -the so-called NIR-FT-Raman technique - has made it possible to obtain Raman spectra of most samples uninhibited by fluorescence. In addition, the introduction of dispersive spectrometers with multi-channel detectors and the development of several varieties of Raman spectroscopy has made it possible to combine infrared and Raman spectroscopy whenever this appears to be advantageous. 

Tungsten filament lamp A convenient source of visible and near-infrared radiation. 

Sharon A, Rosenblatt D, Friesem AA (1997) Resonant grating-waveguide structures for visible and near-infrared radiation. J Opt Soc Am A 14 2985-2993... 

Fig. 7.8.12 Night-vision improvement system using near infrared radiation from modified headlamps [13]...

FIR Far Infrared Radiation, NIR Near Infrared Radiation, VIS Visible Radiation... 

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