| Summary: | 碩士 === 國立中央大學 === 機械工程研究所 === 81 === In recent years,because of the progressive development in
optical communication and optical device,many prople focus on
the research of single crystals.In many kinds of single-crystal
the Laser Heated Pedestal Growth(LHPG)is the optimum one to
grow small diameter single crystal. this method provides some
advantages,such as high growth rates,using in ambient or vacuum
atmospheres,andno contamination with container etc.Now we use
LHPG method to grow LiNbO3 which has some nonlinear optical
properties. The quality of the resultant crystals are strongly
the heating source.In the present study,I investigate the
effect the fluid motion in the melt on the quality of the
resultant and the expermental conditions as follows:growth rate
0.19 mm/min,no ratio reduction,diameter 2mm ,and power using
from 9.2w to 13.2w.From the experimental results,the powerf
luctuation results in striations on the crystals. Since no
striations are and the impurities are constrated near the
peripheral region in resultant crystal,we conclude that the
oscillatory flow did not appear in the present growing
condition.
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