Research Of Optical Filter And Absorber Based On Metallic Micro/Nanostructure

Optical filter is a relatively common optical device,which has the function of wavelength selection by passing or cutting off specific wavelength or waveband.In recent years,with the rapid development of research of nanophotonics and technologies of nanofabrications,optical filters based on micro/nanostructures are gradually known and adopted.Compared with traditional color filters with dyes,optical filters with micro/nanostructures have high resolution and high stability,open up many potential applications,like color display,biosensing,and information storage.However,there are still problems of optical microfilters.Generally speaking,optical filters and absorbers only work efficiently at specific waveband,and for color filters,only one color can be output;micro/nanostructures are fragile,and are difficult for large area fabrication.In order to solve these limitations,in this paper,a series of researches are carried out on optical filters based on micro/nanostructures.(1)The working principle of optical filters based on micro/nanostructures,including the Drude model of metals and the basic principles of surface plasmon polaritons,are introduced in this work.The dispersion relationship,coupling method and different types of surface plasmon polaritons are introduced,which laid the theoretical basis for subsequent research.(2)Common fabrication and characterization methods in micro/nanostructures are introduced,as well as their relative advantages and disadvantages,which laid the experimental basis for subsequent research.(3)Focusing on the problem that most optical filters can only output one kind of color,an active color filter comprised of arrays of asymmetric cross-shaped nanoapertures is proposed in this work.This color filter realizes multicolor output with different polarization angles of lights illuminations.The range of color output can be adjusted by appropriate parameters selection.The underlying mechanism of multicolor output and the influence of size parameters on transmission spectra are investigated to build an efficient color generation strategy.It is vertified by simulation that this color filter is angular independent to the incident light.The transmission maximum of the active color filter we designed is over 70%and the average transmission in the visiable waveband is over 40%.Later,we try to design and simulate types of color filters with Y-shaped and star-shaped,to find a way to display a wider range of colors.Finally,we fabricate cross-shaped color filters and characterize them,which vertify the multicolor display of this type of color filter.(4)Focusing on the problem that most absorbers only work efficiently at a narrow waveband and the micro/nanostructures are fragile and difficult to large-scale fabrication,metallic glasses are applied in absorber design.The superior performance of metallic glasses is introduced and a serious of AuCuSi metallic glasses thin films are fabricated and characterized,and two types of broadband absorber are designed with AuCuSi and CuZrAl metallic glasses thin films and their absorption behaviors are simulated.The underlying mechanism and the influence of size parameters on absorption spectra of absorbers are investigated by simulation.The average absorption of designned broadband absorber is over 97.0%in the wavelength from 500 nm-1300 nm.Finally,we fabricate these types of absorbers and their absorption behaviors are characterized.By taking into account the fabrication and measurement errors,the absorption spectra are in reasonable agreement with the simulation results,which vertify their absorption performance and the feasibility of metallic glasses application in the field of optical nanodevices.In the end,we summarize our research and results in this work.Some problems to be solved in this research are proposed,and the directions of future research and application fields of optical filters based on metallic micro/nanostructures are put forward.