本文发展了一种描述锁模激光脉冲序列输出的全量子理论.采用“相干叠加”模型,即认为从多模相干态光场不同模吸收光子后的原子态是相干的,耦合形成相干组合态.考虑锁模激光各模式间相位关系.用多模相干态描述光场,应用预解算符和投影算符推导演化算符,使本方法可统一处理锁模激光脉冲序列输出及原子的共振多光子过程.

A quantum theory for pulse-train from the mode-looked laser has been developed. In the theory the author uses "coherent superposition" model, i. e. the atomic states are coherent after absorbed photons from different modes of a mode-locked laser. So the final atomic state should be coherently added. The resolvent operator and projector operation are used to derive the operator U. Considering the phase relationship between the modes, the light field are described by multi-mode coherent state. This method can be used to describe the resonant multi-photon processes that the pulse train fxom the mode locked laser interacting with atoms.