Research On The Key Technology Of Large-scale Fabrication Of High-precision Continuous Relief Micro-optical Elements

continuous relief micro optical elements have many excellent characteristics such as: small size,light weight,planarization and easy integration in array an so on,so they are very suitable for the requirements of modern photoelectric systems.They are the future development trend of optical elements,and many continuous relief micro optical elements have been used in 5G technology,artificial intelligence technology,big data technology,etc,and all of these areas need large-scale application of micro optical elements?Because of the low precision,efficiency and high cost of the continuous relief micro optical elements,the large-scale application of the elements is seriously affected.Focusing on the improvement of the preparation accuracy,this paper systematically studies the problems existing in the theoretical design,fabrication and accurate detection,etc.By analysis of the physical and chemical mechanism of the problems above,we proposed the corresponding solutions,and after experiments are taken,the results verify the accuracy is improved the and the defect is reduced.At last we obtains the following innovations and conclusions:(1)This paper studies the error sources in the fabrication of the original mold,and proposes new method such as: array machining path optimization designing,array dynamic frequency sampling,the cell machining optimization algorithm,and the error pre-compensation technology,these methods improve the overall uniformity of the mold and the accuracy of the micro-structure.The PV value of the profile accuracy is nearly 10 times higher than that of the existing methods by a single machining.Through the research on the optimization of raw materials and large area relay fabricating technology,we get compound eye mold with surface roughness up to 1nm,and curvature radius uniformity error of ±0.2% in 170 mm * 170 mm area.This work makes it possible to develop large area array and imaging grade micro-optical elements.(2)In view of the low efficiency and high cost of micro optical mold preparation,which is difficult to be directly applied as the working mold,the paper puts forward the technology of multiple transfer of nickel working mold with high thickness and low stress,which makes different materials mold can be effectively made into an integrated nickel working mold.Further more we develop multilayer film as the anti-sticking and wear-resistant layer,which improves the durability of the mold.Through experiments,continuous relief molded glass micro optical elements with accuracy error better than±1% was made.This index can basically reach the practical level of high-precision large-scale preparation of micro-optical elements.(3)In order to solve the problem of high precision designing and inspection of continuous relief,the tolerance formulation of single lens and the composite design method of array distributed are studied.The methods of data extraction,data processing,surface fitting and error statistical analysis are studied,and the data transformation processing and analysis software is developed,so that different formats data that measured by different testing equipment can be extracted completely without error,and then transformed into the same format data file for processing and analysis.Compared with the traditional detection methods,the method above improves the integrity and accuracy of the profile data,and improves the detection accuracy,so that forming a closed-loop feedback for the optimization and improvement of the large-scale component fabrication.On the basis of the above research on designing,fabrication and detection technology,two typical continuous relief micro optical elements are taken as examples to carry out application research.One example is 4 channels microlens array with profile accuracy RMS value of 13 nm is fabricate,and the other example is random micro-cylinder lens array witch is used as line beam homogenizer,and obtaining quality the same as theoretical designing,which verify the feasibility of high-precision continuous relief micro-optical elements large-scale preparation technology.The above work is expected to achieve large-scale application in 5G optical communication parallel transmission and artificial intelligence 3D computer vision.