基于动态全息的面内微振动测量系统  

In-Plane Micro-Vibration Measurement System Based on Dynamic Holography

作　　者：申旭 高炅烨 薛勇 张斌[1] 冯其波[1] Shen Xu;Gao Jiongye;Xue Yong;Zhang Bin;Feng Qibo(Key Laboratory for Luminescence and Optical Information of the Ministry of Education,Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]北京交通大学发光与光信息技术教育部重点实验室,北京100044

出　　处：《光学学报》2023年第5期130-135,共6页Acta Optica Sinica

基　　金：国家自然科学基金(51775034)。

摘　　要：为了实时测量高频、微小面内振动,利用硅酸铋(BSO)晶体的光折变特性搭建了基于动态全息的面内微振动测量系统。通过粗糙表面的散射信号光携带面内振动信息,与参考光在晶体内干涉形成动态全息并实时衍射,参考光的衍射光和信号光的透射光之间形成新的干涉,通过光电探测器对干涉信号进行解时域或频域的探测,即可得到振动信息。以剪切式压电陶瓷驱动的散射片为被测物,实验测量了0.5~240 kHz的亚微米量级的面内振动。Objective The measurement of high frequency and micro-vibration plays a critical role in multiple fields,such as nondestructive testing,micro machinery,materials science,biomedicine,and aerospace.Optical measurement methods with high accuracy,non-contact,and other advantages are widely applied to avoid device interference and damage.Compared with out-of-plane vibration measurement,in-plane vibration measurement is difficult because the measured light cannot be incident parallel to the in-plane vibration direction.Speckle interferometry is the most commonly used method for in-plane displacement measurement.However,owing to the high-speed performance limitation of the charge-coupled device(CCD)in the imaging process,its measurement frequency cannot be increased.In addition,the measured vibration surface is typically rough,leading to low measurement sensitivity for traditional laser interferometry.The dynamic holographic vibration measurement method based on a photorefractive crystal has attracted increasing attention due to advantages such as wavefront matching and low-frequency cutoff.In this study,a dynamic holographic in-plane vibration measurement system based on bismuth silicate(BSO)crystal is examined,which measures high frequency and small in-plane vibration in real time.It has strong anti-interference ability and is suitable for rough surfaces.Methods The laser beam emitted from the source is split into a reference beam and a signal beam.The signal beam carrying in-plane vibration information passes through a scatterer driven by shear piezoelectric ceramics.Both beams interfere in a BSO crystal.According to the photorefractive properties of BSO crystal,a refractive index grating is formed on the crystal which is equivalent to the interference recording in holography.The grating automatically meets the Bragg condition,and the reference beam generates Bragg diffracted beam in real time,which is equivalent to the diffraction reproduction in holography.The diffracted beam of the reference beam passing through t

关 键 词：测量 动态全息 面内振动 硅酸铋(BSO)晶体 振动测量 

分 类 号：TH825[机械工程—仪器科学与技术]