TY - GEN
T1 - Transport phenomena in growth and annealing of laser crystals
AU - Fang, H. S.
AU - Cai, D.
AU - Zhang, H.
AU - Zheng, L. L.
PY - 2006
Y1 - 2006
N2 - Cloudiness, bubble core defects, anomalous absorption, low-angle grain boundaries, and cracking are the main problems in the growth of high quality and large diameter (>7cm) Yb:S-FAP crystals utilizing the Czochralski method. The generation mechanism of these defects is highly related to transport phenomena in the growth system. In this paper, firstly, inductive, conductive and radiative heat transport phenomena are examined in the entire growth system. Then, an integrated modeling and experimental study is presented to determine an efficient means to eliminate or reduce crystal cracking during cooling. A process model has been developed to simulate the crystal cooling process. The effect of temperature distribution on thermal stress in the crystal during cooling is predicted by a simple but effective computational algorithm. With the relationship between the power change and crystal surrounding temperature change, the process model is further used to optimize power ramp-down profile to avoid cracking of the crystal during cooling-down process.
AB - Cloudiness, bubble core defects, anomalous absorption, low-angle grain boundaries, and cracking are the main problems in the growth of high quality and large diameter (>7cm) Yb:S-FAP crystals utilizing the Czochralski method. The generation mechanism of these defects is highly related to transport phenomena in the growth system. In this paper, firstly, inductive, conductive and radiative heat transport phenomena are examined in the entire growth system. Then, an integrated modeling and experimental study is presented to determine an efficient means to eliminate or reduce crystal cracking during cooling. A process model has been developed to simulate the crystal cooling process. The effect of temperature distribution on thermal stress in the crystal during cooling is predicted by a simple but effective computational algorithm. With the relationship between the power change and crystal surrounding temperature change, the process model is further used to optimize power ramp-down profile to avoid cracking of the crystal during cooling-down process.
UR - https://www.scopus.com/pages/publications/85196535916
UR - https://www.scopus.com/pages/publications/85196535916#tab=citedBy
U2 - 10.1115/IMECE2006-13831
DO - 10.1115/IMECE2006-13831
M3 - Conference contribution
AN - SCOPUS:85196535916
SN - 0791837904
SN - 9780791837900
T3 - American Society of Mechanical Engineers, Heat Transfer Division, (Publication) HTD
BT - Proceedings of 2006 ASME International Mechanical Engineering Congress and Exposition, IMECE2006 - Heat Transfer
PB - American Society of Mechanical Engineers (ASME)
T2 - 2006 ASME International Mechanical Engineering Congress and Exposition, IMECE2006
Y2 - 5 November 2006 through 10 November 2006
ER -