CaF_2晶体的生长与光学性能

Crystal Growth and Optical Properties of Calcium Fluoride

采用导向温度梯度法(TGT)生长CaF2晶体,建立了生长炉内的垂直温度梯度场。研究表明影响晶体质量及光学性能的主要因素包括坩埚材料、温度场、生长程序及原料纯度等。从大量的实验中总结出TGT法生长高质量CaF2晶体的生长条件如下:石墨坩埚;轴向梯度≤2℃/mm;生长降温速率1.5～2.5℃/h;冷却速率≤40℃/h。

CaF_2 single crystals were grown by directional temperature gradient technique (TGT), whose vertical temperature gradient field was determined.The dependence of crystal structure and optical properties on the growing parameters including crucible material, temperature field, growing procedure and purity of raw materials was studied. From enough experiments, appropriate conditions for growing high quality CaF_2 single crystals by TGT were established: graphite crucible, axial temperature gradient≤2℃/mm, growth rate=(1.5-)2.5℃/h, cooling rate≤40℃/h.