光學外差表面粗糙度測量術

Abstract

本論文提出一種外差光學共軸的技術來量測物體表面的 粗糙度,運用 這技術的光學機構並與電腦結合,以達成自動化量測的目的並減少龐大資 料處理過程中的單調性,且能及時顯示測量結果也達到光電系統整合目的. 首先利用所調制的電光晶體得到差頻的目的,參考信號與測試信號之間的 相位差是粗糙的函數,藉由分析這函數可計算出表面粗糙度值. We utilized the principle which foci are different for parallel polarized beam and vertical polarized beam passing through birefringent lens ;the beamwhich it is focused on the sample surface and acts astest beam ; the other beam which is collimated and illuminates a small area on the sample surface and acts as reference beam . since E-O modulated , there is frequency difference between the two orthogonal linear polarized beams , then it measured phase change by a differential interferometer and is to infer roughness by phase chang . this arrangement is simple and analyze easily ; it do not damage the sample surface and relatively cheap to probe-roughness senor.