【作者】 孙佳星；

【导师】 苑立波；

【作者基本信息】 哈尔滨工程大学 ， 光学工程， 2007， 硕士

【摘要】 近年来，低频微小振动测试技术的研究受到了越来越多的重视，特别是随着现代工程技术的飞速发展，高精度的低频微小振动测量已经成为目前工业和科学发展中迫切需要解决的问题。在综合考虑了众多高精度测量方法的基础上，本文提出了一种用于低频微小振动测量的改进型迈克耳逊激光干涉仪。文中设计了交流相位调制与跟踪的解调方案，增加了准猫眼动镜和PZT相位调制跟踪结构，并分析了干涉仪的工作原理及其结构组成。交流相位调制技术将信号检测由直流转变为交流，实现了信号的频谱搬移，消除了低频噪声的干扰，提高了测量分辨率；相位跟踪技术，有效的抑制了由于外界环境因素(温度、湿度和压强等)干扰引起的低频相位噪声，增强了系统的稳定性；准猫眼动镜不仅消除回射光束所引起的光源波动对干涉仪的影响，而且同角锥棱镜相比还避免了光束偏振度的变化，减少了系统误差，提高了系统的测量精度。搭建了实验平台，对本文提出的激光干涉测量仪进行仿真实验。实验结果表明，干涉仪可以有效抑制诸如温度、湿度和压强等相位噪声的干扰，对100Hz振动信号信噪比为30dB，分辨率达到1nm，干涉仪可以实现低频微小振动的测量。更多还原

【Abstract】 In recent years, it has attached importance to the study of low frequency testing technique. Especially with the rapid development of the modern engineering technique, high precision low frequency vibration measurement has been regarded as the needed be solved problem with the development of industry and science. Based on considering most of the high precision measurement technique, this paper proposed an improved structure of Michelson interferometer which is used to measure the low frequency vibration.In this paper, an alternating modulation phase tracking technique demodulation scheme is designed. And a cat’s eye moving mirror and the PZT phase modulation tracking structure is added. The working principle and the structure of the interferometer are analyzed. The signal’s frequency spectrum convert is achieved, the low-frequency noise jamming is abated, the signal-to-noise of the system is improved and the measuring resolution is enhanced according to the alternating modulation scheme; Phase tracking technique effectively suppress the low-frequency noise which is caused by outside environment factors such as temperature turbulence, vibration, and the stability of the system is enhanced. Quasi cat’s eye moving mirror not only eliminate the backtracked beam which may cause optic source fluctuate influence the interferometer, but also avoid the polarization rate change of the beam, reduce the system error, and improve the system measurement precision, compared with corner cube prism.It constructs a testing platform, and dose simulations according to the laser interferometer proposed by this paper. The experiment results indicate that for the signal with the frequency of 100Hz, the output signal-to-noise is 30dB and the measuring resolution is 1nm. The interferometer can achieve the low frequency vibration measurement.更多还原