双Λ共振原子系统中两脉冲光束的同时慢光传输

Simultaneous Slow Light Propagation of Two Pulse Beams Based on Resonant Atomic System of Double-lambda

在热的铯原子汽室中,借助双Λ共振四波混频效应,实验研究了入射探针光脉冲和产生的共轭光脉冲的同时慢光传输特性。实验中首先将泵浦光锁定在铯原子D1线超精细跃迁F=4→F′=3上,将探针光调至超精细跃迁F=3→F′=3附近扫描,通过对探针光和共轭光增益特性的分析,给出获得最大增益所对应的最佳铯泡温度约110℃。最后,采用365ns高斯脉冲作为入射探针光脉冲,研究了探针光脉冲和共轭光脉冲的延迟时间与双光子失谐的关系。通过改变双光子失谐,探针光脉冲的延迟时间可以从40ns增加到343ns,相应的群速度从1 875km/s减小到219km/s;产生的共轭光脉冲的延迟时间可以从12ns增加到159ns,相应的群速度从6 250km/s减小到472km/s。

The characteristics of simultaneous slow light propagation of the injected probe and generatedconjugate pulses were investigated experimentally in a double-lambda resonant atomic system. Firstly, thepump light was fixed on the hyperfine transition ofF=4→F′=3 and the probe light was scanned aroundthe transition of F=4→F′=3 of Cs D1 line. The 110 ℃ optimum temperature for the maximum gain isobtained by analyzing the gain properties of the probe and conjugate lights. Finally, the dependences ofdelay time of the probe and conjugate pulses on the two-photon detuning were studied with 365 ns injectedGaussian pulse. By adjusting the two-photon detuning, the delay time of the probe pulse can rise from 40ns to 343 ns, corresponding to the group velocity decrease from 1 875 km/s to 219 km/s. At the sametime, the delay time of the conjugate pulse can increase from 12 ns to 159 ns, corresponding to the groupvelocity decrease from 6 250 km/s to 472 km/s.