本文在多原子强耦合腔-QED系统中,利用脉冲宽度为5 ns的强脉冲光在垂直于腔轴方向直接激发原子,脉冲的峰值功率为40 mW,通过光学腔观测激发原子辐射到腔中的光子获得相应的激发光谱。我们发现当光场频率和原子跃迁失谐±80 MHz时原子激发率达到最大,而在共振时原子激发被抑制。我们建立了脉冲光与三能级原子相互作用的模型,通过缀饰态能够解释此现象。

We studied the excitation spectroscopy of atoms in a strongly coupled cavity QED system. The atoms were directly excited by 5 ns laser pulses shining with pulse’s peak power of 40 mW from the side of cavity with a linear polarization perpendicular to the quantization axis. Due to the strongly coupling between the cavity and atom, the excitation of the atom decayed to the cavity mode first and then excaped the system from the cavity. Thus, the output of the cavity reflected the excitation of atoms inside of cavity. We found that when the frequency of the pulses are detunings at ±80 MHz with the atomic transition the exciation of the atoms is maximazied, however the excitation is suppressed when the frequency of the pulses are resonant with atomic transition. The results can be explained by the dressed-state model with a 3-level atom interacting with the laser pulse.