利用迈克尔孙干涉仪测量透明体的折射率..docVIP

利用迈克尔孙干涉仪测量透明体的折射率 母柏松 马孟祺 陈云琳+ 北京交通大学理学院国家级物理实验中心 摘要：光的干涉在光学领域有着广泛的应用，本文提出用迈克耳孙干涉仪测量薄透明体折射率的方法，当被测透明体插入迈克耳孙干涉仪的光路中时，其会与光路呈不同夹角，对应光程变化可通过等倾干涉圆环的变化，根据实验仪器吞吐圆环数、薄透明体厚度、薄透明体折射率、薄透明体与光路夹角之间的关系，据此可同时测得薄透明体厚度和折射率。并且在测量过程中系统不再变动，可使系统误差进一步降低。 关键词：迈克尔孙干涉仪；单色光；分光计；折射率. The index of refraction of transparency measured by Michelson interferometer MU bai-song MA meng-qi CHEN yun-lin (Center of Physical Experiment of School Science, Beijing Jiaotong University) Abstract: Interference of light in the optical field has a wide range of applications, this paper proposes the use of a Michelson interferometer for measuring the refractive index of thin transparent materials method, when the measured transparent body is inserted into the Michelson interferometer light path, the light path at different angles with a corresponding change in optical path length, the equal inclination interference fringes changes, according to experiment instrument handling ring number, thickness of thin transparency, refractive index of thin transparent materials, a thin transparent body and the angle of the relationship between optical path, the simultaneous measurement of refractive index and thickness of thin transparency. In the process of measurement, the system does not change and the system error can be made to further reduce. Key words: Michelson interferometer; monochromatic light; spectrometer; index of refraction; 1 引言 迈克耳孙干涉仪是一种典型的分振幅双光束干涉装置，在物理量测量及检测成像等方面有广泛应用，如：测量钠黄光波长及钠黄光双线的波长差、测量光波的相干长度等【1-3】用迈克尔孙干涉仪测量折射率，一般采用钠光光源，观测白光干涉条纹的方法先调出白光0光程差的彩色干涉条纹，在光路1或2中垂直光线方向插入被测物，再调出0光程差的彩色干涉条纹，反射镜移动距离d与透明体厚度、透明体折射率n、空气折射率n0（n0大致取1）有关系式【4 (1) 由此可得 (2) 但是该方法必须知道薄透明体的厚度或折射率之一，本文一种使用迈克尔孙干涉仪，借助单色光的等倾干涉现象，无需已知厚度，通过间接测量，求得折射率的方法，降低系统误差，提高系统精度。实验设计原理 迈克尔孙干涉仪测薄透明体折射率的原理图见图，图中S为单色光光源，G1和G2是相同的玻璃片，G1镀银使入射光分为等振幅的反射光1和透射光2，G2起光路补偿作