Theory of the Nonlinear Optical Response in One-dimensional Systems: Charge vs. Energy Transfer

为了更好地理解具有不同程度对角线和非对角线无序的系统中能量转移和电荷转移的作用，将发展准一维系统中非线性光学响应的理论，如电子供体-受体晶体、卤素桥接混合价过渡金属配合物、聚硅烷和分子j -聚集体。电荷和激发离域以截然不同的方式影响非线性光学响应的大小依赖性。在研究的初始阶段，将使用非相互作用电子和平均场哈密顿量来获得三阶光学响应的解析表达式。在平均场理论之外，数值计算将在有限链上进行，并外推到晶体极限。这项新拨款由材料研究部和化学部联合资助。由材料研究部和化学部联合资助的一项理论研究计划将启动，以计算准一维材料的非线性光学性质。为了将这些材料应用于各种光子器件，在体积限制下对这些材料进行彻底的了解是必要的。＊＊＊

9312029 Spano A theory for the nonlinear optical response in quasi-one- dimensional systems, such as electron-donor-acceptor crystals, halogen-bridged mixed-valence transition metal complexes, polysilanes and molecular J-aggregates will be developed in an effort to better understand the roles of energy transfer versus charge transfer in systems with varying degrees of diagonal and nondiagonal disorder. Charge and excitation delocalization affects the magnitude and size dependence of the nonlinear optical response in profoundly different ways. In the initial phases of the research, noninteracting electron and mean-field Hamiltonians will be used to obtain an analytical expression for the third order optical response. Beyond mean-field theory, numerical calculations will be conducted on finite chains and extrapolated to the crystal limit. This new grant is funded jointly by the Division of Materials Research and the Chemistry Division. %%% A theoretical research program funded jointly by the Division of Materials Research and the Chemistry Division will be initiated to calculate the nonlinear optical properties of quasi-one-dimensional materials. A thorough understanding of these materials, in the bulk limit, is necessary in order to apply them to various photonic devices. ***