| Autor: |
Ardila, D. Reyes, Barbosa, L. B., Andreeta, J. P. |
| Předmět: |
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| Zdroj: |
Review of Scientific Instruments; Dec2001, Vol. 72 Issue 12, p4415, 4p, 2 Black and White Photographs, 4 Diagrams, 2 Charts, 1 Graph |
| Abstrakt: |
The control of the thermal gradient in single crystal grown by the laser-heated pedestal growth method is demonstrated through focalization of the laser beam into two different regions of the starting feed stock. To create these conditions, an optical component consisting of two incomplete spherical mirrors with the same focal distances was designed and built in copper and coated with aluminum. The performance of this component was tested in the crystal growth of lithium niobate rods with a radius larger than the critical radius calculated from the theoretical model for single focalization of the laser beam. Thermal gradient and temperature profiles along the crystal axis were measured with single and double focalization of the laser beam during the crystal growth process. The measured data indicate that the main differences in the thermal gradients of both configurations are found in the first two millimeters away from the melt–crystal interface. Single crystal rods of lithium niobate grown along the c axis with radius larger than the critical one are demonstrated with the use of this optical component. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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