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Title: The application of the symmetry properties of optical second harmonic generation to studies of interfaces and gases

Thesis/Dissertation ·
DOI:https://doi.org/10.2172/10123252· OSTI ID:10123252
 [1]
  1. Univ. of California, Berkeley, CA (United States)

Optical second harmonic generation has proven to be a powerful tool for studying interfaces. The symmetry properties of the process allow for surface sensitivity not available with other optical methods. In this thesis, we take advantage of these symmetry properties SHG to study a variety of interesting systems not previously studied with this technique. We show that optical second harmonic generation is an effective surface probe with a submonolayer sensitivity for media without inversion symmetry. We demonstrate the technique at a gallium arsenide surface, exploiting the different symmetry properties of the bulk and surface of the crystal to isolate the surface contribution. We also demonstrate that optical second harmonic generation can be used to determine the anisotropic orientational distribution of a surface monolayer of molecules. We apply the technique to study homogeneously aligned liquid crystal cells. To further explore the LC-polymer interface, we used SHG to study the surface memory effect. The surface memory effect is the rendering of an isotropic interface anisotropic by putting it in contact with an anisotropic bulk. Last, we describe some preliminary measurements of a time-resolved spectroscopic study of the phenomenon of second harmonic generation in a gas. The construction of a 500 microjoule pulsed, tunable laser source is described.

Research Organization:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
DOE Contract Number:
AC03-76SF00098
OSTI ID:
10123252
Report Number(s):
LBL-31577; ON: DE92008286
Resource Relation:
Other Information: TH: Thesis (Ph.D.); PBD: Nov 1991
Country of Publication:
United States
Language:
English