法布里-珀罗干涉仪测平板玻璃折射率的方法研究

Refractive index of flat glass measured by Fabry-Perot interferometer

根据光线在法布里-珀罗干涉仪中的传播特点,提出了测量平板玻璃折射率的方法 .首先对法布里-珀罗干涉仪中插入平板玻璃前、后所产生的相邻等倾干涉亮纹直径平方的差值和法布里-珀罗干涉仪内、外介质的折射率之间的关系分别进行了理论分析;然后搭建实验光路,使用移测显微镜对干涉亮纹直径进行观察和测量,在平板玻璃厚度已知的前提下,即可得出平板玻璃的折射率,且实验中观察到的现象和测量结果与理论分析相吻合.

According to the propagation characteristics of light in Fabry-Perot interferometer(FP),a new method for measuring the refractive index of plate glass was presented.And the dependences of the difference between diameter squares of adjacent bright fringes of equal inclinationon the refractive index of the medium inside and outside the F-P interferometer were analyzed theoretically before and after inserting flat glass into the F-P interferometer.When the thickness of the flat glass was known,the refractive index of the flat glass could be calculated by measuring the diameters of bright fringes with reading microscope.The phenomena observed in the experiment and the measurement results were consistent with the theoretical analysis.