A New Third-order Nonlinear Optical Properties Of Hyperbranched Conjugated Polymer Research

With the dramatic development of information science, the disadvantages of some of the electronic components such as slow switching speed, clock displacement, serious crosstalk and high power loss in the present optical-electro and electro-optical convert devices becomes increasingly becomes the bottleneck of the system. All-optical switches (AOS) are among the key issues to solve these disadvantages. The key issue of optical switches is the properties of the third-order nonlinear optical properties of material. With a control beam in charge of the refractive index of the materials, the signal beam transmitting though the material will produce an additional phase difference accordingly, therefore the function of the optical switches can be realized.Determining third-order optical nonlinear materials’performance parameters by testing is one of the very important way to study the third order optical nonlinearity. Such measure can distinguish the difference of different materials’third order optical nonlinearity. They also can reveal the intrinsic causes of the difference from inherent mechanism. Determining these parameters can instruct us to synthesis new materials with better performances and supply reliable data for future design of the devices. Because of these, the thesis composed the following aspect.Firstly, the microcosmic mechanism of macromolecule polymer’s third-order nonlinear optical character is analyzed and the factors affecting material’s nonlinear character are described. The formula to calculate the third-order nonlinear coefficient is deduced in theory in the studying of nonlinear optical character.Secondly, The formula to calculate the third-order nonlinear coefficient is deduced in theory in the studying of nonlinear optical character. Then the Z-scan experimental optical system is set up. In experiment, the data are collected automatically through writing programs by Labveiw software, which makes the experiment conveniently. Yet their structure-relationship is still blurred. We studied our pyrene starbursts third order optical nonlinearity by Z-scan method. The result of these materials gives a new promise to the application of these starburst materials.Thirdly, A series of novel hyperbranched donor-acceptor polyfluorenes based on 1,3,6,8-tertsubstituted carbazole core were designed and successfully synthesized via Suzuki polycondensation. Their molecular structure, optical-electronic properties and third order nonlinearity were characterized through GPC, UV-Vis absorption and Z-scan, respectively. We Studied the materials nonlinearity in solvent and in solid film states. The results of the materials suggest its potential candidate for the application in the devices.