Shang H M, Hung M Y, Quan C G, Tay C J
Appl Opt. 2001 Nov 1;40(31):5615-23. doi: 10.1364/ao.40.005615.
We describe a simple method in which the techniques of fringe-projection, holographic, and shearographic interferometry may be readily realized with a commercial beam-splitting cube, a laser source, and a beam expander. With the use of a computer algorithm, moiré fringes may be derived digitally from the fringes that are projected onto a reference surface and onto an object surface. Successful use of the beam-splitting cube for these optical methods is attributed to the refraction of the two split beams that exit from the two adjacent faces of the cube. By careful orientation of the cube, the two refracted light beams will converge and interfere, resulting in the formation of Young's interference fringes for the fringe-projection method. When the hypotenuse of the beam-splitting cube is placed nearly normal to an illuminated object, both the image and the mirror image of the object will be formed behind the cube where a camera is placed. This optical setup thus forms the basis for double-exposure holography when these two images are fully overlapped and for shearography when the images are slightly laterally displaced.
我们描述了一种简单的方法，利用商用分束立方体、激光源和扩束器，可轻松实现条纹投影、全息和剪切干涉测量技术。通过使用计算机算法，可以从投影到参考表面和物体表面的条纹中数字导出莫尔条纹。这些光学方法成功使用分束立方体归因于从立方体两个相邻面出射的两束分束光的折射。通过仔细调整立方体的方向，两束折射光束将汇聚并干涉，从而为条纹投影法形成杨氏干涉条纹。当分束立方体的斜边几乎垂直于被照亮的物体放置时，物体的图像和镜像都会在放置相机的立方体面后方形成。因此，当这两个图像完全重叠时，这种光学设置构成了双曝光全息术的基础；当图像稍有横向位移时，则构成了剪切术的基础。
