冷分子和超冷分子是目前国际上物理化学领域的研究前沿，可广泛应用于化学、量子信息、凝聚态物理和天体物理等领域，但高密度冷分子的制备和操控一直是具有挑战性的难题。理想的冷分子实验通常以制备在绝对基态的分子开始，而传统静电Stark减速需将基态分子（强场搜寻态）制备到亚稳态（弱场搜寻态）才能实现有效减速，冷分子密度难以提高。本项目拟采用新型的光／电复合场，在Stark减速器中引入高斯光束，对强场搜寻态分子产生横向梯度力，实现高密度基态分子的有效减速；同时利用复合场对分子的排列取向效应，研究光场频率、幅度等参数对分子与外场相互作用势的影响，多参数、多维度调控分子量子态，寻找最优光/电复合参数，进一步提高减速效率。项目的完成可解决强场搜寻态分子和基态极性双原子分子的静电Stark减速难题，获得直观的分子减速物理图像，且新型光/电复合场与分子相互作用机制科学问题的研究，对冷分子的实际应用具有重要意义。

Cold molecules and ultra-cold molecules are the current research fronts in the field of physical chemistry, which can be widely used in chemistry, quantum information, condensed matter physics, and astrophysics. The ideal cold molecular experiment usually starts with the molecules prepared in the absolute ground state, while the traditional electrostatic Stark deceleration needs to excite the ground state molecules (strong-field-seeking state) to the metastable state (weak-field-seeking state) to prepare cold molecules, thus reducing the molecular density. This project intends to use a novel optical/electric combined field to decelerate ground state molecules. With a Gaussian laser beam, a transverse gradient force is generated to effectively bunch the molecules in the strong-field-seeking state. At the same time, the alignment and orientation of molecules in the combined field can be used to study the influence of laser frequency, amplitude and other parameters on the interaction potential between the molecule and the external field, thus multi-parameter and multi-dimensional manipulating molecular states, and finding the optimal optical/electric combined field parameters to further improve the deceleration efficiency. The completion of the project can solve the electrostatic Stark deceleration challenges of molecules in the strong-field-seeking state and polar diatomic molecules in the ground state and provide an intuitive physical image of the molecular deceleration. Furthermore, the research on the scientific problem of the interaction mechanism between the new optical/electric combined field and molecules has great significance in the application of cold molecules.