大光轴倾角的偏光干涉测量方法  

A Measurement Method for Large Optic Axial Angle Based on Conoscopic Interference

作　　者：沈为民[1] 李卫涛[1] 王育红[1] 方涛[1] 

机构地区：[1]中国计量学院光电信息工程系,浙江杭州310018

出　　处：《计量学报》2007年第2期114-117,共4页Acta Metrologica Sinica

基　　金：浙江省自然科学基金(102018)

摘　　要：针对偏光干涉法测量晶体光轴倾角存在精度低、范围小的缺点,提出了用相对光轴出露点的条纹数而不是距离来决定光轴倾角。将条纹数分为整数部分和小数部分,用非线性插值方法求解小数部分,用主截面内干涉条纹的相对位置决定整数部分。对6块铌酸锂晶体在不同单色光源、不同数值孔径下进行测量,结果相当一致。实验表明,光轴倾角的测量范围可有效拓宽,而测量误差可减小到0.1°。When the optic axial angle is measured by conoscopic interference method, there are defects of low precision and small range. So a new method is proposed, in which the optical axial angle is not determined by the distance deviating from the melatope but by the fringe numbers. Fringe numbers are divided into integer portion and decimal fraction portion . The decimal fraction portion is calculated by non - linear interpolation method and integer portion is decided by relative placement of interference fringes in principal section. The results are quite consistent for six pieces of niobate crystals which are measured on the condition of the different light - source and numerical aperture. At the same time, the experimental results show that the measurement range of optical axial angle is increased efficiently and measurement error is improved to 0.1^o.

关 键 词：计量学 单轴晶体 锥光干涉图 光轴倾角 

分 类 号：TB96[机械工程—光学工程]