The New Black Phosphorus Nonlinear Two-dimensional Materials Optical Absorption Characteristics Research

Along with the changing of science and technology,to meet the ultrafast laser technology and optical communication technology of iterative replace,in looking for products that meet the technical requirements have been the bottleneck of technology development.Has obvious nonlinear features of two-dimensional material,such as nonlinear filtering,passive mode-locking and the Q-switched,optical materials market demand is great in optical devices.The third-order nonlinear optical properties of the test is an important way to study with third-order nonlinear material,the theory and experiment of the third-order nonlinear optical research also increasingly get attention.As members of the new 2 d material-black phosphorus,is a kind of layered semiconductor material,single black phosphorus were found after the graphene second single element two-dimensional atomic crystal,because of its with its unique physical and chemical properties set by people's view on traditional nanotechnology,Black phosphorus is a high-mobility layered semiconductor with band-gap sensitively dependent on the number of layers from 0.3 e V(bulk)to 2.0 e V(single layer),and single layer and multilayer black phosphorus has always maintained a direct band gap structure.Black phosphorus are already in the experiment to prove its has a broadband saturable absorption performance,and in a number of band clamping applications verified.But how to further improve the black phosphorus clamping or the Qswitched device performance,based on the further nonlinear optical absorption characteristics of black phosphorus research is necessary.This thesis mainly from the ultrafast laser pulse width parameter on black phosphorus the influence of the thirdorder nonlinear absorption,and the different layers of black phosphate samples the experimental study on the third-order nonlinear optical absorption effect,and obtain the following results:(1)the experimental study on the black phosphorus samples of dispersion in the center wavelength of 800 nm titanium sapphire laser as the light source,under different pulse width measurement of the open aperture of Z-scan.Said the samples respectively in 100,fs,1 ps and ps pulse width of the opening of Z-scan curve.All the curve shows a black phosphate solution with saturable absorption properties.When the peak intensity gradually increased from 6.549 to 776.2 GW/cm2,we can find that the three kinds of pulse width,under the irradiation of nonlinear absorption factor,the third order nonlinear polarizability imaginary part is proportional to the pulse width and quality factor,phosphorus and black dispersion of saturated light intensity is inversely proportional to the pulse width,under three kinds of pulse width modulation depth are basically identical.(2)the experimental study on the dispersion of samples with different layer black phosphorus absorption characteristics,using liquid phase stripping method of the preparation of the three different layers of black phosphorus(5 krpm,7.5 krpm and 10 krpm),its dispersion in NMP solution.Through to build system of Z-scan,with adjustable wavelength range of the femto-second laser as light source,hole under the 600 nm band Z-scan,the results show that the different layers of black phosphorus dispersion has saturation absorbent,as the layer is proportional to the modulation depth.The results based on black phosphorus ultrafast laser application provides experimental reference,provide the basis for design black phosphorus devices.