Optical pumping methods

Answer. There has been little effective interplay between experimental results obtained on single nanostructures grown as quantum-wells and studied by optical-pumping methods and those obtained on bulk nanoscale semiconductors by more conventional NMR approaches. However, this situation may change, since the former studies can provide information about the effects of, e.g., charge carriers or strain or compositional interfaces upon NMR parameters such as chemical and Knight shifts and EFGs in reasonably well-defined systems. 

Weber, H.G., Glass, H.-J., Huber, R., Kompitsas, M., Schmidt, G. and zu Putlitz, G. (1974). Optical pumping method for studying nuclear-spin polarization in alkali dimers, Z. Physik, 268, 91-95. 

A thorough theoretical treatment of optical pumping can be found in the review of Happer [515] and [516]. Specific aspects of optical pumping by lasers with particular attention to problems arising from the spectral intensity distribution of the pump laser and from saturation effects were treated in [517, 518]. Applications of optical pumping methods to the investigation of small molecules were discussed in [508]. 

B. Budick Optical pumping methods in atomic spectroscopy. Adv. At. Mol. Phys. 3, 73 (Academic, New York 1967)... 

The porosity of sol-gel materials is a fundamental characteristic that often needs to be finely characterized. Several physicochemical techniques can be implemented, for example, Xe NMR spectroscopy. Thermally polarized xenon NMR has been used for decades for the characterization of porous materials such as zeolites, mesoporous silicas, and silica glasses, but the technique has been largely improved with the introduction of hyperpolarization of xenon gas via optical pumping methods. In this case, spin polarization can be enhanced... 

B. Budick "Optical Pumping Methods in Atomic Spectroscopy", in Advances in Atomic and Molecular Physics, Vol. 3, ed. by D. R. Bates,... 

In this chapter we shall be concerned mainly with the principles of the technique, the effect of relaxation processes, and magnetic resonance transitions between Zeeman sub-levels. We shall therefore initially describe the experiments in terms of the populations of the ground state sub-levels. The discussion of the effects of phase coherence (Hertzian coherence) and experiments involving transverse pumping is reserved until section 17.8. Moreover the application of optical pumping methods to the investigation of hyperfine intervals and the measurement of nuclear moments is postponed until Chapter 18, as are the applications of this technique in devices such as magnetometers, atomic clocks, and masers. 

Thus, in addition to the extrapolation to zero intensity of the pumping light which must be made to eliminate systematic errors due to the light shifts discussed in section 17.9.7, a further extrapolation of the measured hyperfine resonance frequencies to zero buffer-gas density must be made. Zero-field hyperfine intervals measured by the optical pumping method are listed in Table 18.3, together with a selection of the results obtained by the atomic beam technique. Generally the optical pumping results are more precise than the older atomic beam results. The table... 

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