【摘要】 根据饱和增益理论分析可知,不同抽运光功率对应着介质不同的吸收和增益状态.在吸收介质中,相干布居振荡效应导致光脉冲经历饱和吸收,光脉冲传输延迟;在增益介质中,相干布居振荡效应导致光脉冲经历增益饱和,光脉冲传输超前.本文由铒离子的亚稳态速率方程出发,建立了掺铒光纤中超光速传输的理论模型,同时得到时间超前的数值解析表达式;讨论了低频率段超光速的饱和现象,即超光速在低频段并不随着抽运光功率的增强而加强,而在高频率段随抽运光功率的增加而加强.更多还原

【Abstract】 According to the analysis of gain theory,the absorption or gain of medium depends on pump power.The coherent population oscillation leads the pulse to experience absorption saturation and propagation delay in a medium with absorption.This effect induces the pulse to experience gain saturation and propagation advance in a medium with gain.Making use of the transition rate equation of metastable state poplation,we develop the model of fast light in erbium-doped optical fiber and obtain the analytic expression of time advance.We demonstrate that there is a saturation effect of fast light in low frequency region,but the fast light is enhanced with pump power increasing in high frequency region.更多还原