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Anisotropic focusing characteristics of microdomain structures within crystalline Sr(0.61)Ba(0.39)Nb2O6: the crystal
P G Smith1, G W Ross, P T Brown
1Optoelectronics Research Centre and Department of Physics, University of Southampton, Highfield, Southampton S017 1BJ, UK.
Abstract:
We report the anisotropic focusing characteristics of a spherically configured region of microdomains that have been induced within a cubic-shaped crystal of Ce-doped Sr(0.61)Ba(0.39)Nb2O6. The internal spherical structure focuses extraordinary polarized light, but not ordinary polarized light. The spherical region, which is easily observed via scattering, is formed as the crystal cools after a repoling cycle through the Curie temperature, with an applied field. Analytic modeling of the thermal gradients that exist within the crystal during cooling reveals a small (<1 degrees C) temperature difference between the central and the outside regions. The similarity in shape between these temperature profiles and the observed scattering region suggests a possible mechanism for the growth of this spherical microdomained structure.
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