利用计算全息光栅产生的涡旋光测量物体变形

Measurement of object deformation using vortex beams generated by a computer-generated hologram grating

利用计算全息(CGH)光栅产生的涡旋光束拉盖尔-高斯(LG)光束进行离面位移测量。基于二元叉形光栅产生LG光束的理论,将产生的LG光束作为参考光,加入一束平面光作为物光,设计了离面变形测量实验方案。利用物光和参考光的干涉进行物体变形测量,推导出物体变形前和变形后的干涉光强公式。通过数值计算,分析了利用LG光束进行变形测量的原理。数值模拟实验结果与理论结果基本一致,表明利用CGH叉形光栅产生的高纯度的LG光束可以进行物体变形测量。

The out-of-plane displacement can be measured by using a vortex beam, Laguerre Gaussian （LG） beam, produced by computer-generated hologram （CGH） grating. Based on the principle of using the computer-generated hologram （CGH） grating to produce LG beam, the experimental scheme of the out-of-plane deformation measurement was designed, using the LG beam as reference light and a plane beam as object light. The object deformation was measured by the interference of object light and reference light, and the interference beam intensity formula before and after the tested object deformed was derived. Adopting the method of numerical calculation, the principle of using LG beam for the measurement of object deformation was analyzed. The numerical simulation results were in agreement with the theoretical results, which showed that by the high purity LG beam produced by CGH grating can be used for out-of-plane displacement measurement.