Optimization of the cooling profile to achieve crack-free Yb:S-FAP crystals

Yb:S-FAP [Yb{sup 3+}:Sr{sub 5}(PO{sub 4}){sub 3}F] crystals are an important gain medium for diode-pumped laser applications. Growth of 7.0 cm diameter Yb:S-FAP crystals utilizing the Czochralski (CZ) method from SrF{sub 2}-rich melts often encounter cracks during the post growth cool down stage. To...

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Bibliographic Details
Published in:Journal of crystal growth 2007-08, Vol.310 (16)
Main Authors: Fang, H, Qiu, S, Kheng, L, Schaffers, K, Tassano, J, Caird, J, Zhang, H
Format: Article
Language:English
Subjects:
ENGINEERING
FURNACES
LASERS
OPTIMIZATION
SIMULATION
Online Access:Get full text
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Summary:Yb:S-FAP [Yb{sup 3+}:Sr{sub 5}(PO{sub 4}){sub 3}F] crystals are an important gain medium for diode-pumped laser applications. Growth of 7.0 cm diameter Yb:S-FAP crystals utilizing the Czochralski (CZ) method from SrF{sub 2}-rich melts often encounter cracks during the post growth cool down stage. To suppress cracking during cool down, a numerical simulation of the growth system was used to understand the correlation between the furnace power during cool down and the radial temperature differences within the crystal. The critical radial temperature difference, above which the crystal cracks, has been determined by benchmarking the simulation results against experimental observations. Based on this comparison, an optimal three-stage ramp-down profile was implemented and produced high quality, crack-free Yb:S-FAP crystals.
ISSN:0022-0248
1873-5002