Design And Fabrication Of 3D Filter

In the system of 3D imaging technology,as an important part of the light receiving module,the filter is used to filter out the stray light in the environment.Only the band light of the imaging system is allowed to pass through,which improves the imaging quality.In addition to good optical performance,the filter must also have a certain anti harsh environment performance.At the same time,because it is produced by enterprises,it should be able to achieve mass production.In this paper,according to the needs of the project,making full use of the advantages of complete equipment in the enterprise,based on the optical film design theory,using TFCalc coating design software to design and prepare.Selecting the appropriate coating materials,the production of enterprises involves the cost problem.Therefore,compared with the common coating materials in the market,including TiO2 and Ta2O5 with high refractive index,MgF2 and SiO2 with low refractive index,the combination of Ta2O5 and SiO2 with large refractive index difference is selected.The innovation of this paper lies in the design of the film system.Based on the principle of separation,the front surface of the basic film system is coated with a Fabry Perot narrow band film system(Air/LHL2HL(HL8HL)4HL4HLHL/Sub),and the back surface is coated with a long wave pass cutoff film system(Sub/0.5HL0.5H)S/Air)s/air)to eliminate the bypass band on the front surface,The first layer on both sides is inserted with SiO2 as the protective layer,and the two surfaces are respectively optimized with 31 layers on the front surface and 24 layers on the back surface.Then the two surfaces are superimposed and simulated.After optimization by TFCalc software,the average transmittance of 927?963nm band is more than 97%,and the average transmittance of 350?910nm and 977?1100nm band is less than 0.05%.According to the performance of otfc-1550,the deposition rates of Ta2O5 and SiO2 are 3.5 and 12 ?/sec respectively,The substrate temperature is set to 130? and the vacuum degree is set to 4×10-4 In order to improve the yield and efficiency,a batch of samples were successfully produced and tested.The finished product has passed the appearance,optical properties and reliability tests,and the results show that it meets the requirements of technical indicators,but there are still shortcomings.The error between the measured optical properties and the theoretical optical properties is analyzed in six aspects;The poor appearance is due to the problem of substrate cleaning step and machine cleaning step;After high temperature and high humidity,the transmittance will decrease,so increase the power of ion source again,and then test after production.According to the transmittance test results,it shows that the scheme of increasing the ion source to make the film more compact and isolate water vapor is feasible.