【摘要】 研究了四能级的原子系统无粒子反转受激光放大的问题．对于小信号探测利用计算机给出吸收、增益曲线，并计算出无粒子数反转光放大的阈值条件．更多还原

【Abstract】 The laser amplication four-level atom system without inversion is studied.The absorption and gain spectrum A (ω) of a weak probe beam are given, the thresholdconditions of laser amplication without inversion in four-level atom system is work outas well.更多还原