驱动场相位涨落对开放四能级系统的影响

考虑驱动场相位存在涨落，给出了开放四能级系统的稳态解析解，通过它分析了该系统由于驱动场相位涨落引起的有限线宽对增益、色散和粒子数差的影响.分析显示：线宽的变化不能改变无反转激光系统的特性；线宽的增大必须提高抽运阈值；相对来说退出速率很小时，线宽对增益、色散和粒子数差的影响较弱；当线宽不为零时该系统仍能获得无吸收高色散.

Effects of Driving-field Phase Fluctuation on an Open Four-level System

The effects of phase fluctuation on absorption,dispersion and population difference in an open four-Level atomic system have been analyzed by using the numerical simulation from the steady analytical solution. It is shown that variation of the linewidth cannot change the property of the inversionless lasing of the system;increasing RL reduces the magnitude of the gain and requires a larger Ω value for the onset of the gain;when the exit rate is small,effects of the finite linewidth RL,on the gain,dispersion and population difference is very weak;the system can still get a high refractive index without absorption when the linewidth does not equal to zero.