Polarization Dependent Nonlinear Optical Properties of Biomolecules

普度大学的Garth Simpson在实验物理化学项目的支持下，开发了一个系统框架，该框架将为解释定向生物分子组装的偏振相关非线性光学（NLO）测量提供基础。主要目标是：(1)完善和测试基于微扰理论的计算方法，用于描述生物聚合物的偏振相关NLO特性；(2)开发新的仪器方法，用于二次谐波产生（SHG）、和频产生（SFG）和双光子吸收的详细极化分析；(3)评估微扰理论方法在电子SHG、振动SFG、模型取向细菌视紫红质薄膜和胶原原纤维的电子双光子吸收测量。非线性光学方法作为了解生物系统微观结构的探针具有很大的前景。这个项目将促进新技术的重大发展，这些技术可以有效地用于化学和生物学。这项工作的有益影响将扩展到更广泛的社区，随着自由分发软件包NLOPredict的继续发展，以及发起和组织新的非线性光学年度夏季会议。

Garth Simpson of Purdue University is supported by the Experimental Physical Chemistry Program to develop a systematic framework that will provide a foundation for interpreting polarization-dependent nonlinear optical (NLO) measurements of oriented biomolecular assemblies. The primary objectives are to: (1) refine and test computational methods based on perturbation theory for describing the polarization-dependent NLO properties of biopolymers, (2) develop new instrumental methods for detailed polarization analysis in second harmonic generation (SHG), sum frequency generation (SFG), and two-photon absorption, and (3) assess the range of validity of the perturbation theory approach from combined electronic SHG, vibrational SFG, and electronic two-photon absorption measurements of model oriented bacteriorhodopsin thin films and collagen fibrils. Nonlinear optical methods have great promise as probes to understand microscopic structure in biological systems. This project will enable significant development of new techniques that can be used effectively in chemistry and biology. The useful impacts of this work will be extended to the broader community with the continued development of the freely distributed software package NLOPredict, and initiation and organization of a new annual summer meeting on nonlinear optics.