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Chapter I Brief Introduction...
1.12 Aim of the present study
The advantage of NLO materials in lasers and electro-optics became
clear in the early days of lasers, and enabled the expansion of their limited
spectral regime. Today, there is a large number of nonlinear optical materials
available for specific required wavelengths, with various damage threshold
values and with various optical characteristics. The full characterization of
NLO materials will involve proper documentation of these parameters.
Techniques for measurement of these parameters are numerous and can
readily be found in the literature.
Among organic crystals of NLO applications, amino acids exhibit specific
features of interest [133] such as:
Molecular chirality, which secures non-centro (acentric) symmetric
crystallographic structure,
Absence of strongly conjugated bonds, which leads to wide
transparency ranges in the visible and UV spectral regions
Zwitter ionic nature of the molecule, which favors crystal hardness.
Looking at the properties of various amino acids, three amino acids, viz,
L-listidine, L-threonine and DL-methionine have been selected for doping in
KDP crystals. The aim of the present study is to increase the SHG efficiency
and optical transparency of KDP crystals by amino acids doping without giving
much sacrifice to other properties. This will help further to develop crystals of
better qualities for device applications. In order to investigate that, the present
author has focused his attention on of the following aspects.
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