基于双波混合干涉仪的振动测量及其应用

发布时间：2018-01-02 11:51

本文关键词：基于双波混合干涉仪的振动测量及其应用　出处：《浙江大学》2016年硕士论文　论文类型：学位论文

【摘要】：振动是自然界和生产生活中普遍存在的物理现象。振幅小、频率高的振动和超声振动的测量是非常具有工业前景的课题。本文基于硅酸铋(BSO)晶体中的光折变效应,搭建了自适应的双波混合干涉仪来测量压电陶瓷的微小振动和超声振动。参考光束和信号光束在BSO晶体中干涉形成光强的分布,由于光折变效应形成了一个动态全息光栅,该光栅对参考光和信号光的实时衍射能够使这两束光之间发生能量转移,并将信号光的微小相位调制解调出来,从而得到振动信号。从理论上进行仿真,推导了灵敏度的影响因素,指出了灵敏度与耦合效率之间的关系,理论上探索了波形失真的原因,并在后续的实验中得到了验证。实验上设计并搭建了双波混合干涉仪,讨论了光强比、总光强、外加电压大小对灵敏度的影响,与建立的理论模型相比较,符合的较好；实验上进一步测量了不同频率的振动信号,结果表明至少可以测量10Hz到800kHz的振动信号。使用该系统成功地测量了超声探头的微小脉冲振动,与超声探头自身探测到的结果相一致；继而测量了超声脉冲传播到铝块中引起的超声振动,得到超声脉冲在铝块中来回传播的时间间隔,计算得到了铝块的厚度。厚度测量的结果与超声探头及游标卡尺符合的很好。
[Abstract]:Vibration is a common physical phenomenon in nature and production and life. The amplitude of vibration is small. The measurement of high frequency vibration and ultrasonic vibration is a very promising subject. This paper is based on the photorefractive effect of bismuth silicate (BSO) crystal. An adaptive dual-wave hybrid interferometer is built to measure the tiny vibration and ultrasonic vibration of piezoelectric ceramics. The light intensity distribution is formed by interference of reference beam and signal beam in BSO crystal. Because of the photorefractive effect, a dynamic holographic grating is formed. The real time diffraction of the reference light and the signal light by the grating can make the energy transfer between the two beams and demodulate the tiny phase of the signal light. The influence factors of sensitivity are deduced, the relationship between sensitivity and coupling efficiency is pointed out, and the reason of waveform distortion is explored theoretically. In the following experiments, we designed and built a two-wave mixed interferometer, and discussed the influence of the ratio of light intensity, total light intensity and applied voltage on the sensitivity, and compared with the established theoretical model. Good conformance; The vibration signals of different frequencies have been further measured experimentally. The results show that the vibration signals of at least 10Hz to 800kHz can be measured. The system has been successfully used to measure the tiny pulse vibration of ultrasonic probe. The results are consistent with those detected by ultrasonic probe. Then the ultrasonic vibration caused by the ultrasonic pulse propagating to the aluminum block was measured, and the time interval of the ultrasonic pulse propagating back and forth in the aluminum block was obtained. The thickness of aluminum block is calculated. The results of thickness measurement are in good agreement with ultrasonic probe and Vernier caliper.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TH744.3

【相似文献】