在高斯腔模中失稳性的出现

本文研究了高斯腔膜中的光学双稳问题及失稳 范围。文章首先从Maxwell-Bloch方程出发,导出了高斯光束驱动的含均匀展宽介质的环行腔中场振幅的时间演化方程及定态方程。其次在入射场和     

开放的Lower-ladder型和V型系统的非线性动力学研究

在开放的共振Lower ladder型和V型系统中 ,无激光解的失稳既可以通过Pitchfork分岔发生而导致连续无反转激光输出 ,也可以通过Hopf分岔实现而导致自脉动无反转激光输出。分析了非饱和增益系数、腔损耗速率、粒子注入速率比和粒子退出速率等系统参量的变化对两种失稳的影响。     

Plasma properties of laser-ablated St target in air

Ｐｌａｓｍａｐｒｏｐｅｒｔｉｅｓｏｆｌａｓｅｒ－ａｂｌａｔｅｄＳｔｔａｒｇｅｔｉｎａｉｒＷａｎｇＸｉａｎｇ－Ｔａｉ（王象泰）；ＭａｎＢａｏ－Ｙｕａｎ（满宝元）；ＷａｎｇＧｏｎｇ－Ｔａｎｇ（王公堂）；ＦａｎＸｉ－Ｊｕｎ（樊锡君）；ＷａｎｇＪｕｎ（王军）...     

自由运转环形激光器的横向效应

我们考虑一个带球面镜的均匀展宽的环形激光器,从理论上求得了“优质腔”的失稳条件.分析中使用了平均场近似,并假定费涅耳数远大于1,原子和腔完全调谐.     

开放的简单三能级原子系统中无粒子数反转激光增益及色散的讨论

我们讨论了开放的简单三能级原子系统中实现无粒子反激光的条件,分析了系统的增益与色散对探测场和驱动场的失谐、驱动场Ｒａｔｉ频率、原子注入速率及逸出速率的依赖性。     

Influence of relative phase on propagation effect in open V-type three-level system

In this paper we study the influence of the relative phase between the probe and driving fields on propagation effect in an open Doppler broadening V-type three-level atomic system with spontaneously generated coherence(SGC) by using the calculation result of the density matrix motion equations and the propagation equations of the driving and probe fields.It is shown that the relative phase(Φ) has remarkable periodical influence on the propagation effect,and the period is 2π.By selecting appropriate value of Φ,we can get larger lasing without in version(LWI) gain and longer propagation distance in which gain exists,and hence obtain higher probe field(i.e.LWI) intensity.When Φ=π/2,the largest LWI gain and probe field intensity can be got.In addition,the atomic exit rate(γ0) and ratio(S) of the atomic injection rates also have a considerable modulation role on the phase-dependent propagation effect.In certain value range of γ0(S),LWI gain and probe field intensity increase with γ0(S) increasing.In the open system,LWI gain and probe field intensity much larger than those in the corresponding closed system can be obtained.     

Effect of SGC on transient evolution of GWI in a Doppler broadened quasi Λ-type four-level system

In this paper,we study the effect of spontaneously generated coherence(SGC) on transient evolution of gain without inversion(GWI) in a Doppler broadened quasi Λ-type four-level atomic system.It is shown that transient evolution of GWI is very sensitive to the variation of SGC strength,and the transient maximum value and steady value of GWI both increase with SGC strength increasing.The transient and steady values of GWI with SGC are much larger than those without SGC.When Doppler broadening is present,the transient maximum value and steady value of GWI first increase and then decrease with Doppler broadening width(D) increasing,and the value of D which corresponds to the maximum transient GWI is different from that corresponding to the maximum steady GWI.The time needed for reaching the steady GWI increases with D increasing.The steady GWI,which is larger than that without Doppler broadening(D = 0),can be obtained by choosing appropriate D and SGC strength.     

开放V型系统产生无反转激光的两类时间演化

从旋波、慢变振幅及平均场近似下的密度矩阵运动方程出发,利用数值计算结果研究了开放的V型三能级系统在共振条件下通过Pitchfork分岔产生的连续波无反转激光(LWI)场和通过Hopf分岔产生的自脉动LWI场及相应的各能级粒子数布居的时间演化规律,讨论了系统各参量变化对此时间演化规律的影响。     

脉宽对不同密度介质中传播的超短脉冲特性的影响

利用使用预估校正（PC）-时域有限差分（FDTD）法求得的全波Maxwell-Bloch方程组的数值解,研究脉宽对在不同密度的V型三能级介质中传播的飞秒超短激光脉冲特性的影响。结果表明,不同原子密度情况下,脉宽改变对脉冲传播特性的影响是不同的。当超短脉冲在原子密度较小的稀疏介质中传播时,脉冲不易发生分裂;当脉冲未分裂时...     

Doppler展宽的开放准A型四能级系统中的SGC效应

从不同方面研究了Doppler展宽的开放的准∧型四能级原子系统中自发辐射诱导相干(SGC)对无反转激光(LWI)增益的影响.研究结果表明,当SGC强度一定时,LWI增益总是随Doppler展宽宽度的增加而变小;不管Doppler展宽是否明显,通过选取适当的SGC强度,总可以获得比不存在SGC时大的LWI增益,而且Doppler展宽宽度越小,这一差别越明显;粒子注入速率及退出速率也会对与SGC相关的LWI增益产生明显的影响;开放系统可得到远大于相应封闭系统的LWI增益.