基于全息二次曝光的物体形变测量

摘要

针对全息测量物体形变的缺点,采用全息二次曝光法.首先采用二次曝光法对光波初始物面与变化比较,通过干涉条纹的分布情况得到物体变化；然后用Rayleigh-Sommerfeld衍射对全息图卷积；接着为了得到高质量地反映相对变形场分布的干涉场,对移动相移进行修正,消除刚体位移和倾斜影响；最后用非线性扩散偏微分方程法抑制噪声,通过建立一个关于时间与空间变量的模型,其解作为恢复测量数据.实验仿真了全息二次曝光系统,实现不连续的相位变为连续相位,测量不同驱动电压的梁移动典型变形情况及单列曲线,得到了较满意的结果,与普通检测方法相比,该方法具有结果直接可靠、不损伤物体等诸多优点.%Aiming at the shortcomings of holographic when measuring the objects deformation, the holographic double exposure method is proposed. Firstly, double exposure method compares the initial light wave-front and its change. Analyzing the distribution of interference streak, the object change is obtained. Then, Rayleigh-Sommerfeld diffraction hologram convolution is carried out. In order to get high quality deformation field distribution, the mobile phase shift is revised to eliminate the influence of rigid displacement and tilt. Finally, using nonlinear diffusion partial differential e-quation method and setting up noise model depending on time and space,the solution of the model is solved as recovering measurement data. The simulation results realize deformation measurement,obtain satisfactory results.