超冷原子中的拉曼增益光栅(英文)

Raman gain grating in an ultracold atomic medium

为提高光栅的衍射效率,提出了基于主动拉曼效应的超冷原子光栅系统。理论研究表明:通过拉曼增益的空间周期性调节,可有效地将沿垂直光栅方向传播的弱探测光衍射到一级方向,同时零级衍射光将被放大。当系统中引进微波场的原子相干效应时,可以进一步提高光栅的一级衍射效率。在一定的条件下,拉曼增益光栅的一级衍射效率可高于电磁诱导相位光栅的一级衍射效率。该系统可作为高效光开关用于全光网络。

This paper demonstrates theoretically that a Raman gain grating can be formed in an uhracold atomic medium driven by a standing wave and a probe field. Due to the spatial modulation of active Raman gain, the weak probe field propagating along the direction normal to the standing wave can be diffracted into the first-order direction effectively, and the zero-order diffracted beam is also amplified. Under manipulation by a microwave field, the first-order diffraction efficiency can be improved to be higher than that of electromag- netically induced phase grating. This system can be used as a highly efficient switch for an all-optical network.