可调合成波长链绝对距离干涉测量

The Absolute Measurement of Distance with Changeable Synthetic Wavelength Chain

本文提出一种利用半导体激光器的波长调谐特性实现的可调合成波长链绝对距离干涉测量方法 ,针对不同的待测距离 ,可选择不同的合成波长链 ,完成对待测距离的由粗测到精测的整个过程。文中基于这种方法构建了干涉测量系统 ,该系统利用压电陶瓷调制的在一条直线上的两个双光束干涉仪 ,使待测距离被包含于一个交流信号的相位项中 ,从而使小数条纹的测量转化为相位测量 ,合成波干涉条纹的小数级次由单波长干涉信号的相位测量值计算得到。文中以外尺寸测量为例描述了实验装置 ,实验结果表明 ,在现有的测量系统和实验条件下 ,待测距离小于 5mm时的测量极限偏差优于 2 0μm。

A method for the absolute measurement of distance with the changeable synthetic wavelength chain is presented. The synthetic wavelength chain can be changed according to the distance to be measured. An experiment system is developed based on a home made tunable 633 nm external cavity diode laser and two dual beam interferometers which are set in one straight line. As the interferometers are modulated by PZT, the unknown distance is included in the phase term of an AC signal. The integer and fractional parts of the synthetic wavelength interference signal are calculated by the measured wavelength and the phase. It is demonstrated that this experiment system has a standard deviation of less than 2 0 μm at a measuring range of 5 mm. A better measurement accuracy can be achieved easily by improving the performances of the experiment equipment.