Electromagnetic simulation model of microscopic scattering dark-field imaging for optical components surface defect detection

摘要

An electromagnetic simulation model of microscopic scattering dark-field imaging was built based on the finite difference time domain (FDTD) method. The scattered light distribution of different defect's size was obtained. Results show the span of distribution curve and the distribution peak are relative to the defect's width and depth respectively. In the width range of 0.5 μm to 1 μm, there is a linear relationship between the distribution span and the defect's width. Its goodness of linear fit reaches 0.9. Within the depth range of 0.1μm, the distribution peak linearly changes with the depth. But with the depth becomes deeper, the linear relationship between distribution peak and defect's depth disappears. The results in this paper can provide instructive reference for the defect's size inversion.