Optics and Photonics Society of Iran

In this paper, two interferometric methods for surface morphology measurement has been investigated. The simulated sample considered for this study was a diffraction grating with 600 lines per millimeter. A simulated interference pattern for this sample was created and Fourier transform and phase shifting methods have been utilized for the extracting surface profile from that of interference pattern. The code for each method has been written in MATLAB and by using numerical image processing, the obtained surface profile for each method was analyzed. The results demonstrate that in the ideal systems with low percentage of noise the morphological error in phase shifting method is less than Fourier transform method. However, sensitivity of Fourier transform to noise variation is less than phase shifting method and it is recommended to use this method for the noisy systems.