GaAs激光器激发带球面透镜圆柱套层光波导纤维的调整误差分析

本文分析了调整误差对GaAs激光器激发带球面透镜圆柱套层光波导纤维的影响,结果是横向偏差的影响比轴向偏差大得多,这使得基模激发效率的下降速率略快于指数函数.     

磷酸盐光波导激光器放大自发辐射的理论研究

系统地研究了Er3 :Yb3 共掺磷酸盐玻璃波导的性质,在稳态情况下建立并求解速率方程.利用数值分析的方法模拟了980nm二极管激光器抽运时激光器的放大自发辐射(ASE)特性.模拟时用到的主要参数为:信号光的散射损耗α(1530)=8.2×10-2dB/cm,980nm时Yb3 的吸收和发射截面积分别为5.4×10-25m2和6.9×10-25m2,980nm时Er3 的吸收和发射截面积分别为1.65×10-25m2和1.21×10-25m2,Yb3 -Er3 间的能量传递系数为1.9×10-23m3/s,共谐上转换系数为8.09×10-25m3/s.     

一种特殊的双包层圆柱光波导的研究

本文研究了一种双包层阶跃型光波导，内包层的折射率大于芯及外包层的折射率，因而可作为导波层。文中严格的推导了柱坐标下该光波导的特征方程，详细计算了ＴＥ波和ＴＭ波的传播常数、场分布及功率分布；作出了相应的曲线，表明了导波层的厚度、折射率及工作波长对此类光波导传播特性的影响。     

一种特殊的双包层圆柱光波导的研究

本文研究了一种双包层阶跃型光波导，内包层的折射率大于芯及外包层的折射率，因而可作为导波层。文中严格地推导了柱坐标下该光波导的特征方程，详细计算了ＴＥ波和ＴＭ波的传播常数、场分布及功率分布；作出了相应的曲线，表明了导波层的厚度、折射率及工作波长对此类光波导传播特性的影响。     

带波导层的高亮度发光二极管(计算)

本文以能向光纤内提供功率大、寿命长的光传输用光源为目标,提出了在有源层两边形成吸收系数小的波导层的端面辐射型发光二极管,并作了理论分析。在分析中,通过在光线近似中引进一个统计近似,推导出了有源层产生的光功率的光取出效率ε_e,并得出如下结论:(1)如果α_aL(α_a——有源层的吸收系数,L——发光二极管的长度)>>1,光取出效率ε_e 就会比双异质结构发光二极管的光取出效率ε_e 大得多。(2)如果减小有源层的α_a,并在满足α_aL>>1的条件下,由于 L 非常大,因而即使在低的工作电流密度下,也能获得很     

一种多层波导光传播计算的新方法

提出了一种新的简单的一光学方法，可以使用在多层波导的光传播计算中，尤其是在光探测器的设计中。把设计值与目前普遍采用的ＢＰＭ法进行比较，结果吻合较好。与ＢＰＭ法相比，此法最大的优点是在计算中考虑了材料对传播光的吸收，而在光场达到稳定分布后再考虑吸收，故在理论上此方法更加接近实际。作为例子用这种方法计算了一种新型的探测器的尺寸。这种探测器与Ｓｉ波导的集成器件正在制作 中。     

SOI平面光波导有效折射率的计算及其波导层厚度的设计

从麦克斯韦理论出发精确计算得出ＳＯＩ平面光波中的有效折射率及光场分析，并由此确定了传输单模光波导的波导层厚度。     

Theoretical analyses on short-term stability of semiconductor fiber ring lasers

Detailed analyses of the short-term stability of the semiconductor fiber ring laser (SFRL) are presented. Analysis with rate equations shows that the relaxation oscillation effect does not exist in the SFRL. With a frequency-domain model, the mode competition in the SFRL is shown to be suppressed by the gain saturation effect of the semiconductor optical amplifier. Thus the observed good short-term stability of SFRL is theoretically explained. The analyses are verified in experiments.     

Theoretical model of optical fiber secure communication system with chaotic multiple-quantum-well lasers

Chaotic synchronization of injected multiple-quantum-well lasers of optical fiber system and a theoretical model of optical fiber chaotic secure communication system are presented by coupling a chaotic multiple-quantum-well laser synchroniza- tion system and a fiber channel. A new chaotic encoding method of chaos phase shift keying On/Off is proposed for optical fiber secure communications. Chaotic synchronization is achieved numerically in long-haul fiber system at wavelength 1.55 μm. The effect of the nonlinear-phase of fiber is analyzed on chaotic signal and synchronization. A sinusoidal signal of 0.2 GHz frequency is simulated numerically with chaos masking in long-haul fiber analog communication at wavelength 1.55 μm while a digital signal of 0.5 Gbit/s bit rate is simulated numerically with c1haos masking and a rate of 0.05 Gbit/s are also simulated numerically with chaos shift keying and chaos phase shift keying On/Off in long-haul fiber digital communica- tions at wavelength 1.55 μm     

球面端面锥形发散梯度折射率透镜的设计理论

本文系统地研究了球面端面的锥形发散梯度折射率纤维透镜的几何光学设计理论以及用作激光束变换元件的设计规律。     

Theoretical characterization of Raman oscillation with intracavitypumping of fiber lasers

Theoretical results relating to the generation of continuous-wave (CW) output from fiber lasers that are internally pumped with light generated from the stimulated Raman effect are presented. This investigation establishes the important fiber and resonator parameters, such as the fiber length and glass composition, dopant concentration, and pump power required to realize this new form of fiber laser arrangement. Three examples are studied: the Ho³⁺-doped silica fiber laser that is pumped at a wavelength of 1.15 μm, the Er ³⁺-doped silica fiber laser which is pumped at 1.48 μm and, the Tm³⁺-doped silica fiber laser which Is pumped at 1.625 μm. These three examples cover first Stokes pumping, second Stokes pumping, and first Stokes pumping with direct dopant absorption of the pump light, respectively. The simulations involve the use of simple numerical models comprising the spatially dependent field propagation equations (under the slowly varying field approximation) and the rate equations for the population densities. It is established that intracavity Raman pumping of fiber lasers with first Stokes radiation is efficient when the losses at the pump, Stokes and laser wavelengths are kept low (<10 dB/km). It is also established that second Stokes pumping is, even with direct absorption of the pump light, theoretically quite efficient and, as a result, the Er³⁺-doped silica fiber laser which is pumped with second Stokes radiation at 1.48 μm may provide the best demonstration of intracavity Raman pumping     

Geometrical birefringence in a class of step-index fiber

Based on a scalar wave equation including the geometrical effect, an effective-index method is developed for the calculation of geometrical birefringence, i.e., the difference in phase velocity between the two fundamental polarization modes, in a weakly guiding step-index fiber, of which the core can be of rectangular, elliptical, rhomboid or any other shape belonging to the same class, with arbitrary aspect ratio. Numerical results show that the method is very efficient and accurate in obtaining the birefringence and can also provide very useful information on the birefringenee-induced dispersion in the fiber.     

球端面光纤耦合界面烧蚀现象的实验研究

本文提出大功率半导体激光器(LD)对光纤耦合界面的烧蚀的理论假设,得出系统耦合效率随时间的变化关系为ηt=η0t-αβmsk=η0t-αβρ。制作出三种不同直径的光纤端面小球,并对其防烧蚀性能进行了实验研究。实验证明激光器对光纤的烧蚀主要集中在粘接剂区,且大直径的球端面光纤能有效的减小烧蚀对系统耦合效率的影响。从而证明了公式的正确性。     

内含柱面透镜的象散腔

本文用矩阵光学的方法研究了内含柱面透镜的象散腔，给出了其稳定图，此图清楚地显示出由于象散作而使用腔稳定工作区域大大缩小，本文还给了显示象散特征的稳定脸膜参数计算公式，并作了数值计算。     

N阶级联拉曼光纤激光器理论模型

考虑拉曼光纤纤芯有效面积随Stokes光波长变化,提出了一种改进的Ⅳ阶级联拉曼光纤激光器理论模型.根据该理论模型,按照拉曼光纤激光器级联阶数N的奇偶性分别推导出了第N阶Stokes光输出功率的解析表达式.通过忽略经输出耦合器反射回拉曼光纤输入端的残余泵浦光功率,计算了5阶级联拉曼光纤激光器的输出特性,并与相关文献上的实验数据进行了比较,结果显示文中的计算结果与实验结果相吻合.文中的理论模型对于设计N阶级联拉曼光纤激光器有一定指导意义.