A Methodology for Optical Edge Diffraction Analysis Depending on Incident Wavelength and Edge Roughness
G. Çelik, M. Kurt and N. Kaya
Diffraction as being useful and precise measurement method is widely used in sub-micrometre metrology. Scientists make a great effort to enhance precision of sub-micrometre measurements by means of the diffraction method, due to a high potential of diffraction method in metrology. In spite of being made lots of experimental and theoretical study related to diffraction technique as a measurement method, there are so limited studies served detailed mathematical solutions in the aspect of edge roughness and incident beam wavelength. In this study, optical diffraction analysis was conducted theoretically using edge diffraction methodology for different experimental configuration parameters for the combination of incident wavelength and edge roughness. We observed noticeable changes in the diffraction patterns obtained for different roughness and incident wavelengths. The results clearly show that diffraction pattern analysis can be used as an innovative approach to enhance the sensitivity in many applications such as surface analysis, particle sizing, advanced sensor applications, etc.
Keywords: Laser beam, optical diffraction, Fresnel diffraction, wavelength, edge roughness, measurement, theoretical methodology