失谐对开放的∧型系统无粒子数反转激光增益的影响

本文使用开放型三能级无粒子数反转激光模型，从原子密度算符运动方程出发，讨论了定态情况下驱动场和探测场失谐对激光增益和折射率的影响。理论分析表明：若驱动场Ｒａｂｉ频率较小，只有探测场共振时才能得到最大的增益；调整探测场的失谐可以获得无吸收高折射率；驱动场Ｒａｂｉ频率较大而达到某一阈值后，调整探测场的失谐将出现特别增益区。驱动场失谐的变化对折射率产生的影响比对增益更为显著。以上结论与封闭型三能级无粒子

The Effects of Deturnings on the Gain of Noninversion Lasing in an Open Type System

We use the model of noninversion lasing in an open type three level system,start from the equations of the atomic density operator,discuss the effects of detunings of the driving and probe fields on the laser gain and refractive index under steady state case.The theoretical analysis shows that:If the Rabi frequency of the driving field is smaller,the gain can reach a maximum only when the probe field is resonant;the non absorption high refractive index can be obtained by adjusting the detuning of the probe field.When the Rabi frequency of the driving field is larger and reach a threshold,a special gain region will appear by adjusting the detuning of the probe field.The detuning variation of the driving field will have a more obvious effect on the refractive index than on the gain.the special gain region in the latter.