CAJ | 학술논문

三能级Upper-ladder型系统中,在旋波、慢变振幅近似下,求解了考虑驱动场相位扩散后的系统密度矩阵运动方程,并给出了这个三能级梯型系统稳态线性解析解.利用对密度矩阵运动方程的稳态线性解析解的数值模拟结果,研究相位扩散对无反转激光增益、色散和粒子数差的影响;利用对密度矩阵运动方程的数值模拟结果,分析相位的扩散对无反转激光场及相应的各能级粒子数布居的时间演化规律的影响.驱动场相位扩散会导致无反转激光增益减小.线宽的存在阻碍了系统的无吸收高色散.线宽的变化不能改变ladder型系统输出(反转还是无反转)激光的特性.但线宽影响了系统达到稳态的时间以及时间演化过程中的相位扩散将导致相干的减弱.
삼능급Upper-ladder형계통중,재선파、만변진폭근사하,구해료고필구동장상위확산후적계통밀도구진운동방정,병급출료저개삼능급제형계통은태선성해석해.이용대밀도구진운동방정적은태선성해석해적수치모의결과,연구상위확산대무반전격광증익、색산화입자수차적영향;이용대밀도구진운동방정적수치모의결과,분석상위적확산대무반전격광장급상응적각능급입자수포거적시간연화규률적영향.구동장상위확산회도치무반전격광증익감소.선관적존재조애료계통적무흡수고색산.선관적변화불능개변ladder형계통수출(반전환시무반전)격광적특성.단선관영향료계통체도은태적시간이급시간연화과정중적상위확산장도치상간적감약.
In the rotating wave and slowly varying envelope approximations,the density-matrix motion equations for the three-level cascade system equation are solved under the influence of driving-field phase diffusion.The exact linear analytical solutions of the three-level cascade system with the driving field having the phase fluctuation in the steady state are obtained.The effects of phase diffusion on absorption,dispersion and population difference in a three-level upper-ladder system and on the time of steady-state limit in the course of time evolution have been analyzed by using the numerical simulation from the steady linear,analytical solution and density-matrix motion equations.Gain of the probe field will be decreased due to the driving-field phase diffusion.The presence of the finite linewidth induced by the driving-field phase diffusion prevents the ladder system from obtaining a high refractive index along with zero absorption.Variation of the linewidth can not change the property of the lasing in the upper-ladder system.The linewidth as a result of the driving-field phase diffusion has influence to the time of steady state limit and the phase diffusion leads to a decay of the coherence in the course of time evolution.