云母晶体双折射率色散特性的研究

针对云母晶体材料本身性质所决定的双折射率色散关系不一致性,给波片设计带来非常不利的影响,提出偏光干涉法研究云母的色散特性.即由分光光度计测量出云母晶体的偏光干涉谱,通过对干涉谱极值点所对应波长的精确判断,准确计算出极值点的最大双折射率,获得从紫外至近红外光波段云母晶体的双折射率色散曲线,经多项式拟合数据处理,得到任意波长的双折射率色散公式.为求解不同温度任意波长的云母晶体双折射率提供了一种精确简单的方法,对云母晶体器件的设计与使用有重要的理论依据和参考价值.

Study on the Dispersion of Birefringent Indexes of Mica Crystal

The inherent discrepancy of birefingent dispersion relations of mica crystal has an unfavourable effect on designing wave-plate. A way of the polarization interference spectrum to study the dispersion of birefringent indexes of mica crystal is presented. The polarization interference spectrum of mica wave-plates are measured with spectrophotometer. Then through accurate judgment extreme points of the polarization interference spectrum, the maximal birefringent index at the extreme points can be calculated exactly and the dispersion curve is obtained from visible spectral band to ultraviolet spectral band. At last, expressions of the birefingent dispersion at any wavelength for mica crystal can be achieved through polynomial fitting data processing. This paper offers a accurate and simple method for measuring the birefringent index of mica crystal at any wavelength and temperature, also offers parameter choice basis for correctly using and designing crystal mica devices.