Polarisation spectroscopy

E. W. Thulstmp and J. Michl, Tlementary Polarisation Spectroscopy, VCH Pubhshers, New York, 1989. 

Litvinenko KL, Webber NM, Meech SR (2001) An ultrafast polarisation spectroscopy study of internal conversion and orientational relaxation of the chromophore of the green fluorescent protein. Chem Phys Lett 346 47-53... 

The secondary electron spin-polarisation spectroscopy (SESPS).112... 

Deconvolution of these peaks would yield a distribution of Q2 and Q3 sites as a function of temperature. However, cross-polarisation spectroscopy is not automatically a quantitative technique, since the signal s intensity depends -amongst others- upon the proximity of protons and upon the contact time, used in the experiment. 

An important development in microwave/optical double resonance, called microwave/optical polarisation spectroscopy, was described by Ernst and Torring [42], The principles of this technique are illustrated in figure 11.22. A linearly polarised probe beam from a tunable laser is sent through the gas sample and a nearly crossed linear polariser, before its final detection. Polarised microwave radiation resonant with a rotational transition in the gas sample is introduced via a microwave horn as shown, and resonant absorption results in a partial change in polarisation of... 

Figure 11.22. Experimental arrangement for microwave/optical polarisation spectroscopy [42].

Separation applications are also worthy of investigation if some entirely novel principle is involved. For example, Dunkin et al. have recently demonstrated [29] the ability to form an anisotropic imprinted polymer. This was achieved by selective blocking or filling of cavities employing polarised photo-chemsitry and a photochemically active template. An anisotropic polymer of this type might offer an opportunity to use polarised spectroscopy in an optical sensor device. 

Winter et al. [140] suggested that haem a is bound to subunit II. If so, it may be uniquely located because it is a bisimidazole complex and the number of conserved histidines is limited. It would then be expected to be near the C domain, sandwiched in part between transmembranous helices [92] (Fig. 3.4). This would agree with the perpendicularity between the haem and membrane planes observed by polarised spectroscopy of orientated enzyme specimens [141-143]. 

King SM, Vaughan HL, Monkman AP (2007) Orientation of triplet and singlet transition dipole moments in polyfluorene, studied by polarised spectroscopies. Chem Phys Lett 440(4-6) 268-272... 

Fluorescence polarisation spectroscopy is still very much used to probe the rotational dynamics of single molecules, either on surfaces or in solution [152]. In bioa-nalytical assays the fluorescence emission intensity is measured as a function of rotational speed. When a solution of fluorophores is excited with polarised light, the fluorophores selectively absorb those photons that are parallel to the transition moment of the fluorophore, resulting in photoselective excitation. The fluorophore molecules rotate to varying extents during the fluorophore lifetime. If the fluores-... 

FTIR polarisation spectroscopy was used to study the orientational behaviour of the different constituents of a liquid crystalline block copolymer (copolyester-imide) during uniaxial elongation at different temperatures. Differences in the degree of alignment (as well as in the response to the application of the mechanical load) were observed. With increasing temperature, the level of the applied stress and the induced degree of orientation decreased, while the differences in the orientational behaviour of the mesogen and the flexible spacer were retained (243). 

The saturated absorption method has been applied by a number of authors to the study of the Ha transition. The technique is often preferred over its rival polarisation spectroscopy because the latter gives in general a mixture of symmetrical and asymmetrical lineshapes... 

Figure 18. Experimental arrangement for Faraday modulated polarisation spectroscopy.

Thus, a potentially very useful application of the modulator is in polarisation spectroscopy (figure 18) where for uncrossed polarizers the signal is in general a mixture of dispersion and Lorentzian lineshapes. With a modulator the dispersion contribution alone can be extracted thus avoiding the systematic error in the determination of the linecentreC ]. 

R.E. Teets, F.V. Kowalski, W.T. HiU, N. Carlson, T.W. Hansch, Laser polarization spectroscopy, in Advances in laser Spectroscopy. SPIE Proc., vol. 113 (1977), p. 80 R. Teets, Laser polarisation spectroscopy. PhD thesis, Physics Department, Stanford University, 1978... 

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