平衡式干涉仪的光学系统设计

介绍了两种平衡式干涉仪的光学系统设计方法,分别给出了用于单端测量和双端测量的具体设计方案.由于采用的平衡式光学系统中测量光束和参考光束具有近似相等的光程长度和相似的路径,其光程差仅由被测件的长度或被测表面与测量参考镜之间的距离而引起,因此干涉仪具有很高的稳定性.用双端测量双光程平衡式干涉仪对准零长度试样进行测量,在185 h测量中所得数据的标准偏差为2.1 nm.

The Design of the Optical System in the Balanced Interferometers

Two methods to design optical systems for the balanced interferometers are introduced. Optical systems for both single-sided measurement and double-ended measurement with each type of balanced interferometers are presented. Since the interferometers have balanced optical systems , in which the measurement beam and the reference beam have similar paths and equal optical path lengths except for the path difference caused by the sample length or the distance between the measurement and reference surfaces, and they have high stability. Measurement of a quasi-zero-length sample using a double-pass balanced interferometer by double-ended measurement showed that the standard deviation of measurement in 185 h is 2. 1 nm.