Researches On Patterned Absorber And Its Application In Multi-channel Filter

Patterned filters are one of the key issues for the miniaturization and integration of many optical systems and equipment,and play an important role in the fields of multispectral imaging,detection,and information sensing.This thesis focuses on the filter patterning technology,and researches and analyzes several different filters patterning process,mainly involving the following contents.First,the common types,developments,and main preparation methods of filters are briefly introduced,and the application fields of patterned filters are also explained.Then we introduce several common patterning methods and explain the principles of the main processes of photolithography.Secondly,the role of solar sensors in aerospace was studied.A patternable wideband absorber film system with metal-dielectric structure was designed,and a wideband absorber was prepared in an ion-assisted deposition device.The average reflectance@400-11OOnm of the absorber is only 0.9%,and it has good angular insensitivity within 50°.Finally,a biaxial solar sensor was patterned by photolithography-wet etching method.Thirdly,we studied the patterned masking method for making five-channel filters.A double cut-off combination structure was selected,and a five-channel visible-near infrared band-pass filter film system was designed with TiO2 and SiO2 as high and low refractive index material.Filters for each channel were prepared using ion-assisted deposition.The filters have good steepness and deep cutoff,each channel has a transmittance of more than 93%,and the center wavelength is offset within 3.5nm.Finally,the absorption film system designed in Chapter 3 was used to pattern the alignment mark and window area of each channel of the five-channel filterFinally,based on the porous structure of anodized aluminum,we propose an angle-insensitive micro-nano structure filter with adjustable color.Cyan,magenta and yellow filter are prepared.The filters have good color purity in the visible band,the maximum reflectance can reach about 70%,and has good angular insensitivity within 45°.The Lift-Off technology was then used to prepare a two-color filter with a cyan hawk pattern on the basis of the yellow filter,further demonstrating the simplicity of the filter's spectral adjustment of this structure.