一种利用散斑干涉和灰度等级测量纳米级位移的新方法

为了解决散斑干涉计量中亚波长位移测量的困难，相移技术被广泛使用，但相移技术有其固有缺点，应用非常麻烦。这里提出一种不同于已往相移技术的全新微小位移测量方法。即把灰度等级法和散斑干涉计量相结合以实现对亚波长位移或变形的测量。克服了散斑干涉计量中变形或位移小于半个波长不产生完整条纹时计量困难的缺点,论述了其测量原理并进行了实验。实验结果很好地证明了上述方法的可行性。为精密散斑干涉计量提供了一种更简单有效的方法。

New method for displacement measurement in nanometer level using speckle interference and gray level

The phase shifting method is widely used to eliminate the difficulty of the subwavelength displacement measurement in the speckle interference metrology, but it is very inconvenient to use. In this paper, the microdisplacement measurement method using the hybrid of gray-level and speckle interference is proposed, which is different from the previous phase shifting method. This method overcomes the difficulty of finding a complete fringe pattern when the deformation or displacement is less than half of a wavelength. The measurement principle of the method was described, and the experiment was carried out. The feasibility of this method was verified. Therefore, an easier method is given for speckle interference metrology.