Measurement And Evaluation Of Surface Profile Parameters Of Planar Optical Elements

One of the most important issues in the optics applied fields is accurate evaluation of surface quality of optical elements.And surface quality includes surface shape,waviness and roughness.Currently,the instruments used to measure the surface shape and the waviness are mainly based on the high precision interferometer,compared with the profilometer which is usually used for measuring the roughness.By measuring kinds of parameters,surface quality can be evaluated quickly.Evaluation parameters from different manufacturers are different.How to establish the correlation in different instrument measurement results and achieve transformation in different instruments have become an important question.The differences evaluation results are caused by different evaluation parameters and different selections of the instruments in the process of measurement.This dissertation focuses on the surface quality evaluation of planar optical components,discusses the research status of the surface quality evaluation,analyzes the basic parameters of the surface quality evaluation,studies the stability and correlation of the surface shape evaluation parameters and analyzes the consistency of the profiler measurements.First of all,the definition and the evaluation criteria of the peak-to-valley value,root mean square value,power spectral density and roughness are given in the evaluation of surface optical quality of planar optics.Secondly,in terms of the contingency and uncertainty of the peak-to-valley value in the surface quality evaluation of high-precision optical components,analyses the repeatability and stability of PV,PVm,PV20,PVq and PVr with different wave surface by simulation and experimental studies.Finally,The experimental results show that the stability of PVq and PVr is better than that of PV,PVm and PV20.By analyzing the relationship between the peak-to-valley and RMS values in the single-component aberration,the multiple-component integrated wavefront and the actual measured wavefront,single plane aberration or multiple aberration synthetic image can be evaluated by single PV value or RMS value.However,for the actual measured wavefront,parameters need to be comprehensively evaluated by PV and RMS parameters.Finally,the Form Talysurf PGI Optics Contact Profiler and the NewViewTM 8000 Series 3D Optical Profiler are used to measure the samples with different microstructures,and analyse whether the choice of the sampling points,measurement range and baseline selection would effect results.By setting the sampling length,calculating the Gaussian filter center line,the least squares median line and the least square curve,the roughness values under different evaluation standards are calculated.When the evaluation length is equal to the sampling length of five sections,the roughness values under the three evaluation criteria have little deviation from the profilometer measurement results,and the results of the least squares neutral line are the closest to the results of the profilometer measurement.The analysis of variance is used to assess instrument repeatability and reproducibility,and the%GRR of the NewViewTM 8000 Series 3D optical surface profilometer is equal to 25.65%,according to the judgment standard,the instrument can be used normally under certain conditions.Through the simulation and experimental research,we can find that the most important significance is the analysis in stability and relevance of the evaluation parameters and the consistency of the profile instrument,which provides a reference for the evaluation of the surface quality of optical elements.