Abstract : based on the enhanced effect of spontaneous emission in cavity quantum electrodynamics , the microcavity effect of vertical cavity surface emitting lasers ( vcsels ) is analyzed , and the results obtained in ordinary open cavities and in three - dimensional closed cavities are compared 文摘:依据腔量子电动力学中自发辐射增强效应，分析了垂直腔面发射半导体激光器的微腔效应，比较了普通开腔和三维封闭腔中的结果。
In the two - photon resonance case , part of the input pulse energy is transformed into higher and lower frequency components through amplified spontaneous emission and four - wave mixing , and the medium shows strong optical power limiting effect 在双光子共振情况下，即入射脉冲频率等于1 、 3能级之间的共振频率的一半，由于介质中放大的自发辐射和四波混频的作用，部分入射脉冲能量转化为高频和低频电场成分的能量，分子介质表现出了很强的光功率限幅特性。
The properties of spontaneous emission depend not only on the relative position of the resonant frequency from the edge of the photonic band gap and the photonic mode density but also on the relative distance of the atomic space position from the sidebrand . and we study other property of spontaneous emission 其性质除了依赖于原子上能级与光子频率带隙边缘的相对位置或光子态密度，还依赖于原子的空间位置与侧支距离。并对原子的自发辐射的其它特性进行了分析。
In succession , the theory of chirped - pulse amplifier system is given in detail , firstly , studying from designing experimental light road and optical components to theoretical analysis , we par ' tly finished the system by ourselves . about ultr a - shoft pulse with a pulse - width of 9 . 8f s and output power of 650mw and band - width of about l 20nm is output from oscillator source , secondiy , the stretching capacity of single grating four - pass stretcher is measured using abcd matrix combining collins function , and the effect of relativ e parameters to the streching ratio is also simulated . thirdly , a new type of disjunctional frequency moduiating function is provided according to the gain - narrowing and gain - saturation which are appeared in the co urse of amplification , under modulating the two effects are both controlled on some e xtent , fourthiy , the effect of ase that is often ignored by people is analyzed and the resolving methods are also given 从光路、光学元件的自行设计到理论分析计算，初步建立了一台实验系统；采用abcd矩阵法结合collins公式计算了四通式单光栅展宽器的展宽量，并模拟了相关参数对展宽比的影响，对实验具有指导意义；评价了再生放大器和多通放大器的优缺点，对放大过程中通常忽略的放大自发辐射现象（ ase ）进行了分析，并提出了相应的解决方法；针对放大过程中出现的增益窄化和增益饱和现象，对输入种子脉冲提出了一种新的分段频率调制函数，实现了对增益窄化效应和增益饱和效应的共同抑制；提出了系统的材料（包括放大介质和光路中的普通介质）正是融合高阶色散的来源。
In the focal plane of z = 0 , the smaller the dss of the fhb , the higher the optical potential , and the greater the corresponding optimal detuning 8 , which are beneficial to atomic lens because it cannot only be profitable to obtain an atomic lens with a higher resolution , but also helpful to reduce the spontaneous emission and photon scattering effects of atoms in the fhb 在焦平面上，聚焦中空光束的dss越小，光学势越大，相应的最佳失谐量越大，这对原子透镜的性能越有利。因为这不仅容易得到高分辨率的原子透镜，而且还可以减少在聚焦中空光束中原子的自发辐射和光子散射效应。
The methods and the experimental setups for measuring the gain and noise figure of an edfa are emphasized . we introduce how to measure the characteristics of each component of an edfa , especially the gain and absorption coefficient of an erbium doped fiber ( edf ) . thirdly , four types of simple and novel l - band edfa structures with low noise , high gain and low gain ripple are proposed to satisfy the requirement of a dwdm system 基于考虑自发辐射噪声( ase )的giles模型，建浙江大学博士学位论文立了这种edfa的全光增益箱制理论模型;理论和实验分析了四种可能的光路结构、泵浦波长、光纤光栅反射波长和反射率、泵浦功率以及掺饵光纤长度等参t对其箱制特性的影响。
It is found that the fwm field can cause the asymmetry of electromagnetically induce transparency profile . in addition , the effect of different propagating orientations of probe field on the electromagnetically induced transparency is also discussed . in the molecular multi - level system with the perturbed superposition levels , we discuss the electromagnetically induced transparency , spontaneous emission enhancement , double dark resonance and double electromagnetically induced transparency by using the density matrix equation under weisskopf - winger approximation and dressed - state density matrix equation 针对实际的实验条件，考虑了一种影响量子干涉的新的因素-四波混频场，研究了四波混频场对双光子探测的-型能级体系的eit的影响，发现四波混频场能够导致双光子探测的eit线型的不对称，在此基础上，讨论了不同探测场的传播方式对eit的影响，针对分子中实际存在的包含有微扰能级的不同多能级系统，我们分别采用缀饰态绘景下的密度矩阵方程和weisskopf - wigner近似下的密度矩阵方程详细地讨论了电磁感应透明、自发辐射的干涉相消和相长、双暗态共振和双电磁感应透明现象。
However , the intensity gradient ( force ) of the diffracted light of the semi - gaussian beam is far smaller than that of the evanescent - light wave , so its spontaneous emission probability is greater than that from the evanescent - light one when the normal velo city of the incident atom is greater 然而，因为半束兰失谐高斯光束衍射光场的强度梯度力远小于消逝波光场，所以当入射原子速度较大时，原子在半束兰失谐高斯光束衍射光场中的自发辐射几率要大于消逝波光场。
It is shown that the divergence angle of pumping beam and off axis pumping and spontaneous radiation influenced the linewidth of parametric light more quickly than those of other factors did , and the linewidth of parametric light is very narrow far away from the degeneracy point , and the linewidth begins to large quickly at the degeneracy point 结果表明，泵浦光的发散角、泵浦光的偏轴泵浦、自发辐射对参量光的线宽影响较大。在远离简并点处，线宽较小，在简并点处，线宽较大。
In addition , the control of spontaneous emission of a three - level atom embedded in photonic crystals was investigated in this paper , because the model of two - level atom is siple . as it shows , the properties of spontaneous emission depend not only on the relative position of the resonant frequency from the edge of the photonic band gap and the photonic mode density but also on the intial atomic state 二能级毕竟是最简单的模型，故在最后，还对光子晶体中三能级原子的自发辐射特性进行了研究。结果表明，其自发辐射除了依赖于原子上能级与光子频率带隙边缘的相对位置或光子态密度外，还依赖于原子的初始状态。
