随着实验技术的发展和提高，多维（二维、三维）光谱技术已成为研究物理学，化学，生物学以及材料科学等的一种重要手段。同时与多维光谱有关实验技术的发展也对其相关理论提出了挑战。本项目的研究目标是从我们近年所发展的单分子发射光子统计的产生函数理论方法出发，发展分子体系二维非线性光谱的产生函数理论方法，并对其相应过程的(超快)动力学过程进行研究。这一理论方法将通过分析由分子体系发射的光子所携带的丰富信息获得分子体系的二维非线性光谱及其所包含的物理信息，通过该理论方法获得分子体系发射光子的高阶矩及其关联，分析抽取分子体系二维光谱所含的新信息，并对其做出新的理解、探讨新的谱图以及所表现出的新现象等。由此，研究分子体系以及受环境影响的动力学变化过程及其途径；分子体系的超快非线性光谱技术物理极限及其对应的指纹特征；并发展有关的数值计算方法和相应计算软件。为分析、理解多维光谱信息提供新的理论和计算方法。

With the development of experimental technology, the technoloy of multidimensional optical spectroscopy has become a versatile and powerful tool for the study of physical, chemistral, biological and materical science. At the same time, the advent of multi-dimensional optical spectroscopic techniques, has led to the challenge in the theory of multi-dimensional optical spectroscopy. In this proposal, our goal is to develop a new theoretical approach of two- (and three-) optical spectroscopy in molecular system (Two-dimensional Spectroscopy of Molecular System via Generating Function Approach) based on the photon counting statistics emited from single molecule system via generating function approach developed by us recently. We investigate the ultrafast dynamics in molecular system by employing this new theoretical method. In this new theoretical approach of two-dimensional spectroscopy, we will analyze the information of the time-depvelopment photons emited from molecular system to obtain two- (and three-)dimensional spectroscopy. We can also underatand the new physical and chmical processes in the multidimensional optical spectroscopy via the high moment and their correlation moments. From our new theoretical approach of multi-dimensional spectroscopy, we investigate the ultrafast dynamical process; and the physical limits of ultrafast process in molecular process. We also develop the new numerical approach and program, this would be to provide the spectroscopist a new theoretical method and numerical calculation.