基于光纤声光调制的轮廓检测技术研究

为实现对工件表面微观形貌测量系统要求远距离传输、实时在线及非接触测量，同时达到高精度、高分辨力、高信噪比测量，提出基于声光调制的光纤外差法轮廓检测技术，采用外差法可有效抑制随机噪声，提高信噪比，通过原理分析建立数学模型；系统设计画出工件表面粗糙度测量框图；实验测量得出被测工件表面粗糙度，分辨力达到1 nm；讨论了不确定度来源及控制方法，测量精度为1。实验结果表明:外差法、声光调制及光纤测试技术可有效降低噪声、提高分辨力和测量精度。

Contour detection based on optical-fiber acousto-optic modulation

In order to meet the requirements of component surface micro-topography measurement system for remote transmission and real-time online non-contact measurement, as well as high accuracy, high resolution and high signal-to-noise ratio measurement, we presented an optical-fiber heterodyne method of contour detection based on acousto-optic modulation. We established the mathematical model through the principle analysis, drew the suface roughness measurment block diagram and measured the suface roughness of the testing component with achieving the resolution of 1 nm. Moreover, we discussed the source of uncertainty and control method, the measurement accuracy was 1‰. Results show that the noise, resolution and measurement can be improved by the fiber-optic hererodyne contour detecting technique based on acousto optic modulation.