Lehmann P, Patzelt S, Schöne A
Appl Opt. 1997 Apr 1;36(10):2188-97. doi: 10.1364/ao.36.002188.
A new approach for determining the roughness of engineering surfaces that is applicable to industrial in-process measurements is introduced. Laser speckle patterns, arising from light scattered from rough surfaces that are illuminated by polychromatic laser light, are detected in the far-field region. The incoherent superposition of these light intensities and the angular dispersion cause the effect of speckle elongation. This is characterized by increasing speckle widths and leads to a radial structure of the speckle patterns. With increasing surface roughness, the elongation is replaced more and more by the decorrelation of the monochromatic speckle patterns for the different wavelengths. Such effects were detected with the CCD technique and analyzed by local autocorrelation functions of intensity fluctuations that were calculated for different areas of the speckle patterns. The results of surface-roughness determination by means of the speckle elongation effect are presented.
介绍了一种适用于工业过程测量的确定工程表面粗糙度的新方法。在远场区域检测由多色激光照射粗糙表面散射的光产生的激光散斑图案。这些光强度的非相干叠加和角色散导致散斑伸长效应。其特征是散斑宽度增加，并导致散斑图案的径向结构。随着表面粗糙度的增加，伸长越来越多地被不同波长的单色散斑图案的去相关所取代。利用电荷耦合器件（CCD）技术检测到了这种效应，并通过为散斑图案的不同区域计算的强度波动的局部自相关函数进行了分析。给出了利用散斑伸长效应确定表面粗糙度的结果。
