多光束激光外差高精度测量玻璃厚度的方法

The method for multi-beam laser heterodyne high-precision measurement of the glass thickness

利用基于激光外差测量技术和激光多普勒技术的非接触式多光束激光外差测量方法,得到了光电探测器输出电流的谐波表达式.讨论了该测量方法用于玻璃厚度超精密测量的可行性及理论依据,并利用Matlab软件对不同情况进行了仿真实验.结果表明:该方法在不同入射角时测量平板玻璃厚度最大的误差为0.3%,明显比其他测量方法精度高.

Multi-beam laser heterodyne measurement of glass thiclcness is based on laser heterodyne measurement technology and laser Doppler technology. We deduced the harmonic expression of photodetector output current, discussed the feasibility and theory of the method which make use of the non-contact multi-beam laser heterodyne to increase the precision of the glass thickness measurement, and made simulation in different situation with Matlab. The results showed that the maximum error is 0. 3 % at different incidence angles in flat glass thickness measurement, which has an obvious advantage in accuracy over the other methods.