梯-型三能级系统中自发辐射的量子相干控制

Study on the quantum coherent control of spontaneous emission in three ladder-type sysem

采用从基态到第一激发态为双激光场驱动的物理模型,对梯形三能级系统中自发辐射的相干控制进行了分析,通过变换驱动激光场之间的相对相位得到了一些主要结果.共振激发时,谱线呈现出三个谱峰的对称形式.当初始相位相同时,两边辐射峰值较高而中间峰值较低.随着初相位差的增加,两边谱峰之间的距离逐渐增大,谱线的高度逐渐下降,中心谱线的高度随着初始相位差的增加逐渐增大,宽度逐渐变小,直至成为一条较为尖锐的线,实现了对两边谱峰的完全抑制效应.采用下能级为双激光场激发的梯-型三能级系统,通过变换激光场之间的相对相位,实现了对激发态自发辐射的量子相干控制,观察到自发辐射光谱的抑制及谱线的猝灭等效应.

The quantum coherent control of spontaneous emission in three ladder-type system is researched by using the physical model of two laser fields drives exciting from the ground state to the excited state. By varying the relative phase of the exciting laser fields, we get the following result, Beeause resonance excited state splits energy levels up, the spectrum lines present the symmetry form about three peak values. When initial phase is same, both sides radiate peak values are higher but lower in the center peak values. Along with increase of initial phase difference, the distance increases gradually between both sides spectrum peak, and the height of spectrum lines gradually descends. When the initial phase difference is equal to pi, spectrum lines disappear eompletely. The height of center spectrum lines increases along with increasing the initial phase difference, and the widths decrease gradually. Until initial phase difference is equal to pi, the center spectrum line becomes eomparatively sharp line, and these realize the entire eontrol both sides spectrum peak. The Can- eellation of spontaneous emission is also gained.