低膨胀固体材料线膨胀系数的干涉测量方法

固体材料的线膨胀系数在精密仪器产业及高精度实验领域是一个非常重要的物理量,要实现对线膨胀系数较低的固体材料进行测量,通常采用激光干涉的方法。采用光路补偿的方法,即激光干涉仪中两干涉臂同支架来测量低膨胀固体材料的线膨胀系数,不但能够抵消支架膨胀对材料受热伸长的影响,还有效地抵消了地面振动对干涉仪的影响,并能够对线膨胀系数在10-6/℃量级的材料的线膨胀系数进行测量。如果改进试验工艺,且采用条纹稳定技术,该方法可以用于更高量级的线膨胀系数的测量。

Measurement of linear thermal expansion coefficient of low expansion materials using interferometery

The linear thermal expansion coefficient of materials is very important in the fields of precision instruments and high precision experiments.To measure the linear thermal expansion coefficient of some ultra low expansion(ULE)materials,the laser interferometer is usually used.In our experiments,the two interferential arms of the laser interferometer are fixed on one bracket,whose the purpose is to compensate the optical path changes caused by other effect except the elongation of the materials.Using this interferometer,not only the linear thermal expansion of the bracket can be counteracted,but also the ground vibration can be counteracted effectively.We measure the linear thermal expansion coefficient of the materials at the level of 10^-6/℃ by this laser interferometer.If the technique of the experiment is improved on and interferential stripes are stabilized,this kind of interferometer can used to measure the linear thermal expansion coefficient at higher level.