Identification of Born-Oppenheimer potential energy surfaces of diatomic molecules from optimized chirped pulses

this paper we explore the feasibility of applying adaptive feedback optimal control to determine Born-Oppenheimer (BO) surfaces. If the molecular wave packet is well localized, laser pulses optimized to transfer population between two surfaces contain information on the potential energy difference in the region scanned by the wave packet in the duration of the pulse. By iterating the experiment with the different values of the nuclear separation large regions of the unknown BO surface can be measured if one of the surfaces is known. The method is simulated with a model experiment on CsI. The results show that the BO surface can be determined with reasonable accuracy. Some limitations and possible extensions of the method are discussed. 1 Introduction The possibility of using external laser fields to control specific chemical reactions or to excite molecules into prescribed states has received considerable attention in recent years; for a recent review see, e.g., [1]. After the pioneering work of Tannor, Rice and Kosloff [2,3] and Brumer and Shapiro [4,5] much theoretical work has been done to establish the feasibility of molecular control. Peirce, Dahleh and Rabitz developed a way of applying the methods of optimal control theory (OCT) to quantum chemical problems which has become the standard formulation of the problem in recent years [6]. A similar Preprint submitted to Elsevier Preprint 18 August formulation was developed by Kosloff et al. [7]. An important step toward laboratory implementation was taken by Judson and Rabitz [8]. They developed a method which, in its extreme form, did not use any a priori information of the system being controlled, rather they used an adaptive feedback method, based on a genetic algorithm (GA), to let the laser learn to achieve con..