Research On Surface Roughness Detection Of Optical Elements Based On Light Scattering

With the continuous development of optical technology,the optical element plays a more and more important role in the field of military,and aviation.Accurate measurement the surface quality of optical components has important significance to optimize the polishing process,the coating process and reduce the loss of thin film devices.Aiming at the shortcomings such as contact,damage and low efficiency in the surface detection methods of optical components,a non-contact differential scattering detection method based on perturbation theory is proposed in this paper.By analyzing the applicable conditions and advantages and disadvantages of different detection methods,determined to use differential scattering method with non-contact and high precision to measure the surface roughness of ultra-smooth K9 glass.Based on the in-depth study on the approximate analytical method of rough surface light scattering,by applying the perturbation theory to the surface roughness measurement of optical components,the differential scattering power(ARS)of the surface of the optical element is obtained,and the mathematical model of surface roughness is established.The feasibility and accuracy of the theory are verified by simulation experiments.Finally,through constructing the differential scanning detection system of optical element for testing the surface roughness of ultra-smooth K9 glass.The results of the differential scattering method are compared with the results of the classical contact atomic force microscopy.The results show that the measurement results are consistent,which further proves that the differential scattering method based on the perturbation theory is effective.The differential scattering method proposed in this paper has the advantages of non-contact,no damage,high efficiency and convenience,which has guiding significance and reference value for improving photoelectric detection performance.