New Frequency Conversion Effects in HIO/sub 3/ and α-LiIO/sub 3/ Single Crystals Showing High X/sup (2)/ and X/sup (3)/ Nonlinear Susceptibilities

Author(s):  
A.A. Kaminskii ◽  
A.V. Butashin ◽  
J. Hulliger ◽  
P. Egger ◽  
P. Mikhail ◽  
...  
2020 ◽  
Author(s):  
P. Karuppasamy ◽  
T. Kamalesh ◽  
Muthu Senthil Pandian ◽  
P. Ramasamy ◽  
Sunil Verma ◽  
...  

2002 ◽  
Vol 747 ◽  
Author(s):  
A. K. Batra ◽  
T. Gebre ◽  
J. Stephens ◽  
M. D. Aggarwal ◽  
R. B. Lal

ABSTRACTLithium niobate single crystal is an excellent material for various optical applications such as frequency conversion, optical switches, optical modulators and others. An automatic diameter control Czochralski crystals growth system has been designed and fabricated. A brief description of the entire system along with software developed has been described. With optimized growth parameters, pure and Fe/Mn doped crystals have been successfully grown using this system. Preliminary characterizations of these crystals have also been presented.


2020 ◽  
Vol 75 (6) ◽  
pp. 557-573
Author(s):  
Naseema Kooliyankal ◽  
Rakhi Sreedharan ◽  
Sarath Ravi ◽  
Raghi Kottoly Ravindran ◽  
Manoj Kumar Thanathu Krishnankutty

AbstractA new organic non-centrosymmetric nonlinear optical (NLO) material, p-nitrobenzylidene-p-phenylamineaniline (PNBPDA) was synthesized and single crystals of PNBPDA were grown from ethanol solution by slow evaporation solution growth technique. Single crystal X-ray diffraction (XRD) and powder XRD data confirm that PNBPDA crystallizes in monoclinic system with non-centrosymmetric space group Cc.Various characterizations like PXRD, fourier transform infrared (FT-IR) spectroscopy, thermal analysis and micro hardness test have been conducted. Optical studies have been done for evaluating the transparency range and the luminescence property of the grown single crystals of PNBPDA. Dielectric studies have carried out to investigate the electronic polarizability within the grown crystal. The frequency conversion efficiency of the grown crystal was determined using Kurtz Perry powder technique and second harmonic generation (SHG) was found to be 6 times that of standard Potassium Dihydrogen Phosphate (KDP). Z-Scan technique was performed to determine the third order non-linear optical properties of the grown crystal of PNBPDA. The optical limiting property and the laser damage threshold value reflect the practical applicability of PNBPDA crystal for photonic applications. Additionally, the theoretical background of PNBPDA was carved out using Density Functional Theory (DFT) by evaluating the geometrical and electronic structural properties from Frontier Molecular Orbital (FMO) analysis, Molecular Electrostatic Potential (MESP) analysis and non-linear features from dipole moment, polarizability and hyperpolarizability properties embedded within the PNBPDA molecule. The calculated first order hyperpolarizability (β) value of the molecule was found to be 14 times that of the standard urea molecule.


Author(s):  
Lucien F. Trueb

A new type of synthetic industrial diamond formed by an explosive shock process has been recently developed by the Du Pont Company. This material consists of a mixture of two basically different forms, as shown in Figure 1: relatively flat and compact aggregates of acicular crystallites, and single crystals in the form of irregular polyhedra with straight edges.Figure 2 is a high magnification micrograph typical for the fibrous aggregates; it shows that they are composed of bundles of crystallites 0.05-0.3 μ long and 0.02 μ. wide. The selected area diffraction diagram (insert in Figure 2) consists of a weak polycrystalline ring pattern and a strong texture pattern with arc reflections. The latter results from crystals having preferred orientation, which shows that in a given particle most fibrils have a similar orientation.


Author(s):  
E. L. Thomas ◽  
S. L. Sass

In polyethylene single crystals pairs of black and white lines spaced 700-3,000Å apart, parallel to the [100] and [010] directions, have been identified as microsector boundaries. A microsector is formed when the plane of chain folding changes over a small distance within a polymer crystal. In order for the different types of folds to accommodate at the boundary between the 2 fold domains, a staggering along the chain direction and a rotation of the chains in the plane of the boundary occurs. The black-white contrast from a microsector boundary can be explained in terms of these chain rotations. We demonstrate that microsectors can terminate within the crystal and interpret the observed terminal strain contrast in terms of a screw dislocation dipole model.


Author(s):  
M.P. Thomas ◽  
A.R. Waugh ◽  
M.J. Southon ◽  
Brian Ralph

It is well known that ion-induced sputtering from numerous multicomponent targets results in marked changes in surface composition (1). Preferential removal of one component results in surface enrichment in the less easily removed species. In this investigation, a time-of-flight atom-probe field-ion microscope A.P. together with X-ray photoelectron spectroscopy XPS have been used to monitor alterations in surface composition of Ni3Al single crystals under argon ion bombardment. The A.P. has been chosen for this investigation because of its ability using field evaporation to depth profile through a sputtered surface without the need for further ion sputtering. Incident ion energy and ion dose have been selected to reflect conditions widely used in surface analytical techniques for cleaning and depth-profiling of samples, typically 3keV and 1018 - 1020 ion m-2.


Sign in / Sign up

Export Citation Format

Share Document