Development of Composite Nonlinear Optical Materials Based on Local Field Enhancement

9223726博伊德我们将进行实验和理论工作，旨在开发具有改进的非线性响应的新的非线性光学材料。我们的方法的基本思想是形成两种（或更多种）成分的复合材料，这些成分在线性和非线性光学性质上都不同。 因此，施加的光波的电场将在两种成分之间不均匀地分布，导致复合材料的有效非线性极化率可以超过其组成材料中的任一种。 在我们最初的理论研究中，我们已经发现了这样的局部场增强至少可以是五倍的现实条件。 在我们的方法中，这两种成分都可以是光学无损的，因此我们的方法应该区别于最近的工作，涉及金属胶体和掺杂荧光剂的玻璃，其中的复合材料是必然吸收。 作为本次调查的一部分进行的实验的目的是在发展的局部场效应的作用，在确定复合材料的非线性光学性能的基本理解，并在开发实际的复合材料与改进的非线性响应。 我们的方法是一般的范围内，也就是说，它是适用于二阶和三阶非线性光学材料，它可以用来增加基本上任何均匀的光学材料的非线性光学响应，通过形成一个复合材料的材料。 然而，我们最初的实验研究将考虑在聚合物光学材料的非线性光学性能的增强。 ***

9223726 Boyd We will perform experimental and theoretical work aimed at the development of new nonlinear optical materials with improved nonlinear response. The basic idea of our approach is to form a composite material of two (or more) constituents that differ both in their linear and nonlinear optical properties. The electric field of an applied optical wave will therefor be nonuniformly distributed between the two constituents, leading to an effective nonlinear susceptibility of the composite that can exceed that of either of its constituent materials. In our initial theoretical studies, we have discovered realistic conditions in which such a local-field enhancement can be at least a factor of five. In our approach, both constituents can be optically lossless, and thus our approach should be distinguished from recent work involving metal colloids and semiconductor-doped glasses in which the composite material is necessarily absorbing. Experiments to be performed as part of this investigation are aimed both at developing a fundamental understanding of the role of local field effects in determining the nonlinear optical properties of composite materials and at developing actual composite materials with improved nonlinear response. Our method is general in scope, that is, it is applicable to both second- and third-order nonlinear optical materials and it can be used to increase the nonlinear optical response of essentially any homogeneous optical material by forming a composite out of that material. However, our initial experimental studies will consider the enhancement in the nonlinear optical properties of polymeric optical materials. ***