A Study On Optical Characterization Of Aphene Based On Phase Measurement Deflection

With the wide application of graphene materials in the fields of electronics,aerospace industry,new energy,new materials,etc.,the surface inspection requirements of graphene films have been widely used in the manufacture of graphene films,lithium ion battery manufacturing,graphene film transfer and Coating technology and other fields.Phase measuring deflectometry based on structured light illumination is an important three-dimensional measurement technique for high-speed,high-precision,low-cost,full-field measurement of mirror and mirror-like objects with uniform surface reflectance.The measurement environment is not sensitive.The reflectivity of the single-layer graphene film is about 0.1%,and the optical absorption change caused by adding a layer of graphene film is about 2.3%.Based on this optical property,the optical characterization of the graphene film can be realized.In this thesis,the optical characterization of graphene films based on phase measurement deflection at macro and micro scales is studied.The optical path structure design of macroscopic and microscopic phase measurement deflection system for optical characterization of graphene films is studied.The calibration method of microscopic phase measurement deflection system based on telecentric optical path was studied.The calibration results were explored in the aspects of graphene layer number and defect characterization.The details are as follows:1.The graphene characterization method based on phase measurement deflection was studied.The detailed optical path structure analysis and design of the macroscopic and microscopic phase measurement deflection system applied to the optical characterization of graphene films was carried out,and the device selection was carried out.The macroscopic and microscopic phase measurement deflection experimental system was built.Preliminary measurements of graphene surface defects on different substrates were performed.The lateral phase measurement deflection system studied in this paper has a lateral resolution of 4.32μm and a detection field of view of 14.0 mm×10.5 mm.The lateral resolution of the microscopic phase measurement deflection system is 1.35/μm,the detection field of view is 1.40mm×1.05mm,and the data of graphene surface and layer number can be extracted after calibration.The image resolution is collected.And contrast has also improved.2.A characterization method of graphene layer number based on interference reflection microscopy system is proposed.The modulation degree image is used for characterization,.and the image contrast is established with the number of layers of graphene film to complete the graphene film layer.The detection of the number.3.The telecentric lens is calibrated in the telecentric microscopic phase measurement deflection optical system.The customized circular calibration target is used to detect the calibration feature points and take pictures of different poses,and the internal reference of the camera is obtained.The external reference calculates the reprojection error of the camera calibration.