Research On Infrared Nonlinear Characteristics Of Two-dimensional Indium Selenide And Spectral Imaging Technology

Two-dimensional Indium Selenide has its great advantages with excellent properties in optoelectronics field,showing in devices as array structural devices,flexible electrodes,and broadband spectral high-speed responders,etc..However,such researches are in the range of visible and near-infrared light,but rarely in mid-infrared reaction and nonlinear characteristics.Thus this paper mainly study the mid-infrared reaction and nonlinear characteristics of two-dimensional Indium Selenide.For the studing of infrared optical properties of two-dimensional Indium Selenide,a Z-scan system and a mid-infrared imaging system are established.Results had shown that two-dimensional Indium Selenide has nonlinear effect in near-infrared range,and high electron fransfer apability in broaband mid-infrared range,which provide value in miniaturization of infrared multifunction devices.The innovation of this paper lies in the programming of nonlinear measurement system controlling and infrared imaging,moreover,the measurement and analysis to the uneven samples prepared by method of liquid phase exfoliation.The main research contents are as follows（1）Nonlinear optical characteristics of two-dimensional Indium Selenide in different near-infrared wavelength pumps are studied.Z-scan system was assembled,and program related to the system was coded to perform control and numerical calculation.Studys had found two-dimensional Indium Selenide with 10649)8)pump shows nonlinear absorption effect in“open-aperture”measurement due to carrier absorption effect,and the transmittance curve feature of“peak to valley”in“close-aperture”for self-defocusing effect.And with 15609)8)pump,only nonlinear-reflection effect occurred but no nonlinear-absorption effect,which proves such wavelength is much beyond the medium intrinsic bandgap.（2）Broadband mid-infrared spectral characteristics of two-dimensional Indium Selenide in different thickness were studied.Spectrums of transmission and reflection are analyzed,which found an interaction between the sample and substrate due to carrier metastasis.The transmittance enhancement effect due to such interaction was maximized up to 18.5%.And conductivities calculated based on spectrum data are in the range of 0～38)/8)from600（88）^-1 to 4000（88）^-1.（3）Spectral imaging of uneven two-dimensional Indium Selenide in different thickness are studied.The broadband mid-infrared transmission and reflection three-dimensional imaging were reconstructed,calculated,and analyzed based on the data collected by spectrometer,and local spectrum changes due to the thickness changes are shown.Three-dimensional conductivity imaging that can tell local conductivity changes are simultaneously shown.This part of research provides technical support for detecting the uniformity of two-dimensional or ultra-thin materials.