Simulation of optical surfaces and their PSD study

The performance of a optical component is greatly dependent on its surfaces. There are many ways to measure and evaluate a surface so far, but actually no one knows exactly what a "real" surface likes, and thus makes some measurement unexplainable. This paper develops a way to construct various synthetic surfaces. Referred to actual AFM measurement, regular or irregular surfaces can be created and studied. Bumps, scratches, granules, profile errors and other construction elements can be added to form a very complicated virtual surface. The number, size and distribution of these elements can be changed, and if necessary, the surface roughness can be controlled in a specialized range. As these surfaces are created synthetically, we know exactly what construction these surface contain. The height data of created virtual surfaces can be transferred into the file that AFM instrument can read and handle. As a typical example, a very complicated surface is created step by step in this paper, and its PSD for each step are calculated. This process mikes it very clear how the surface component element affect its PSD function, and is benefit to our better understanding of real surface construction.