室温条件下掺铒光纤中光脉冲群速可控特性的研究

利用相干布居振荡技术在介质吸收光谱上产生烧孔，孔宽大约为基态粒子数恢复时间的倒数. 由增益理论分析得到不同抽运光功率对介质吸收状态的影响. 在介质的吸收区域，振荡导致光脉冲经历饱和吸收，脉冲传输延迟；在介质的增益区域，振荡又导致光脉冲经历增益饱和，脉冲传输超前. 应用此技术在掺铒光纤中实现了光速人为可控. 在掺铒光纤晶体中观测到了最慢为2.857×10³m/s的光速减慢传输，相应感生群折射率为10.5×10⁴. 根据布居振荡效应及增益理论，由速率方程出发，得到了 关键词： 光谱烧孔 相干布居振荡 饱和吸收 慢光

Controllable group velocity of light pulse in erbium-doped optical fiber at room temperature

In the absorption spectrum of the medium a burning hole appeared by coherent population oscillation, and the linewidth of this feature was approximately the inverse of the ground state population recovery time. Based on the theoretical analysis of gain the effect of absorption was different for different pump power. In a medium with absorption the oscillation leads to the pulse experiencing absorption saturation and propagation delay; in a medium with gain this effect induces the pulse experiencing gain saturation and propagation advance. Making use of coherent population oscillation we controlled the group velocity of light propagation in erbium-doped optical fiber. In experiment, the slowest group velocity was 2.857×10³m/s, and the corrresponding group index was 10.5×10⁴. According to coherent population oscillation and gain, we obtained the analytic expression of the group delay from rate equation and its simulation results were quantitatively coincident with our experimental data. The methods of controlling group velocity were comprehensively analyzed through the analytic model.