基于远失谐的四波混频过程,在实验上得到了放大的探针光脉冲和产生的共轭光脉冲的同时慢光传输,并通过改变抽运光和探针光之间的双光子失谐实现了群速度的同时操控.首先在连续光模式下,研究了入射探针光和新产生共轭光的增益与单光子失谐之间的变化关系.随着单光子失谐在一定范围内加大,探针光和共轭光的增益均表现出先增加后减小的变化趋势.在具有增益特性的基础上,分别采用6μs和365 ns探针光脉冲,研究了慢光的延迟时间和双光子失谐的关系.对6μs的探针光,得到探针和共轭光脉冲的最大延迟分别为2.1μs和1.9μs,对应的群速度分别约为0.000119c和0.000132c,相应延迟比分别为0.35和0.32.对365ns探针光,探针和共轭光脉冲的最大延迟分别为756ns和670ns,对应的群速度分别约为0.00033c和0.00037c,相应延迟比提高到2.07和1.83.
Based on the far off-resonant four-wave mixing process, the slow light propagations of the amplified probe and generated conjugate pulses are obtained experimentally. Simultaneous manipulations of group velocity are realized by changing the two-photon detuning between the pump light and the probe light. The dependences of gains of the injected probe and generated conjugate light on the one-photon detuning for continuous wave mode are studied at different cesium vapor temperatures and pump light powers. It is shown that the maximum of gains occurs at the proper Raman one-photon detuning. The dependence of delay time on the two-photon detuning is measured using the 6μs and 365 ns probe pulses, respectively. For the 6 μs input probe pulse, the maximum delay times of the probe and the conjugate pulses are 2.1 μs and 1:9 μs with the fractional delays of 0.35 and 0.32, respectively, corresponding to 0.000119c and 0.000132c group velocity. The high fractional delays of ns for the 365 ns input pulse are obtained. 2.07 and 1.83 with the maximum delay times of 756 ns and 670