Optical fluorescence spectroscopy

The stresses measured in the AI2O3 along the surface of the specimen by optical fluorescence spectroscopy are shown in Figure 6, along with the FEM predictions. These FEM results are also presented for a... 

One of the difficulties of a quantitative analysis of scale failure is the determination of the stress state in the scalers it results from the oxide growth process and from additional substrate deformations. The application of X-ray diffraction provides usually only a limited lateral spatial resolution. For alumina scales consisting of the a-Al20, phase, Lipkin and Clarke [20] have shown recently that stresses can be measured at RT also by means of optical fluorescence spectroscopy (OFS) employing the piezo-spectroscopic effect [21]. This method permits a high spatial resolution of stress measurements in the micrometre region and is therefore especially useful for the analysis... 

COLORANTS FORFOOD, DRUGS, COSTffiTICS AND TffiDICAL DEVICES] (Vol 6) -analysis using laser-induced fluorescence [SPECTROSCOPY, OPTICAL] (Vol 22) -drinkingwater [ANALYTICALTffiTHODS - PTYPHENATED INSTRUTffiNTS] (Vol 2)... 

A nano-light-source generated on the metallic nano-tip induces a variety of optical phenomena in a nano-volume. Hence, nano-analysis, nano-identification and nanoimaging are achieved by combining the near-field technique with many kinds of spectroscopy. The use of a metallic nano-tip applied to nanoscale spectroscopy, for example, Raman spectroscopy [9], two-photon fluorescence spectroscopy [13] and infrared absorption spectroscopy [14], was reported in 1999. We have incorporated Raman spectroscopy with tip-enhanced near-field microscopy for the direct observation of molecules. In this section, we will give a brief introduction to Raman spectroscopy and demonstrate our experimental nano-Raman spectroscopy and imaging results. Furthermore, we will describe the improvement of spatial resolution... 

In order to relate material properties with plasma properties, several plasma diagnostic techniques are used. The main techniques for the characterization of silane-hydrogen deposition plasmas are optical spectroscopy, electrostatic probes, mass spectrometry, and ellipsometry [117, 286]. Optical emission spectroscopy (OES) is a noninvasive technique and has been developed for identification of Si, SiH, Si+, and species in the plasma. Active spectroscopy, such as laser induced fluorescence (LIF), also allows for the detection of radicals in the plasma. Mass spectrometry enables the study of ion and radical chemistry in the discharge, either ex situ or in situ. The Langmuir probe technique is simple and very suitable for measuring plasma characteristics in nonreactive plasmas. In case of silane plasma it can be used, but it is difficult. Ellipsometry is used to follow the deposition process in situ. 

The protein-containing colloidal solutions of water-in-organic solvents are optically transparent. Hence, absorption spectroscopy, circular dichroism spectroscopy and fluorescence spectroscopy are found to be convenient for studying biocatalysis [53]. The reversed micelles are interesting models for studying bioconversion, since the majority of the enzymes in vivo act inside or on the surface of biological membranes. 

Ultrathin LB PMMA and novolac/diazoquinone films have been demonstrated to act as high resolution electron beam and optical resists, respectively. Structural rearrangements in the LB PMMA films have been observed by using fluorescence spectroscopy. However, this rearrangement did not appear to influence the lithographic performance when seven or more layers of LB PMMA films were used as the resist. A more comprehensive study of the relationship between lithographic performance and LB film structure is currently underway. 

Bublitz [62] used time resolved laser induced fluorescence spectroscopy and fibre optics to determine polyaromatic hydrocarbons in oil polluted soils. The detection limit was 5mg kgy1 oil in soil. 

Finally, in Chapter 11 some advanced techniques are briefly described fluorescence up-conversion, fluorescence microscopy (confocal excitation, two-photon excitation, near-field optics, fluorescence lifetime imaging), fluorescence correlation spectroscopy, and single-molecule fluorescence spectroscopy. 

R. B. Thompson, Fluorescence-based fiber-optic sensors, in Topics in Fluorescence Spectroscopy, Volume 2 (J. R. Lakowicz, ed.), pp. 345-365, Plenum Press, New York (1991). 

Besides the fluorescence coefficient, the optical absorption and scattering coefficients of the sample are the most important parameters in quantative fluorescence spectroscopy of turbid media. In principle two or, if the anisotropy parameter has to be determined, three independent measurements are sufficient to separate the coefficients that appear in all equations as sums or proportions. However, for better accuracy, one of the geometrical parameters (sample thickness, angle of incidence, distance from the irradiated spot) as well as the wavelength of irradiation should be varied over a wide range, and then the data should be fitted with the help of the corresponding model equation. 

---