Depolarization of backscattered linearly polarized light from ZnO thin film

The depolarization behavior of backscattered linearly polarized light from ZnO thin film was investigated experimentally.The results show that the characteristics are related to both the polarization orientation and wavelength of linearly polarized incident light.When the incident light is s-polarized,the depo- larization behaviors are different for different wavelengths.When the incident light is p-polarized,the depolarization behaviors,on the contrary,are similar for different wavelengths.In addition,there is an optimal incident angle for depolarization of linearly polarized light with different wavelengths,which is equal to their effective Brewster angles,respectively.     

金属目标表面温度场对后向散射偏振结构的影响

文章采用基尔霍夫法和微扰法,探讨了表面为大粗糙度表面和微粗糙表面两种情况 下,入射角、金属目标表面温度场对后向散射偏振结构的影响。根据现有条件设计了实验装置,并用该装置测量了部分实验数据,相关结论对激光探测等领域的研究具有一定的参考价值。     

温度对纳米ZnO膜电学光学性质影响的研究

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部分相干平顶光束在大气湍流中空间相干性研究

采用Rytov相位结构函数二次近似的方法和广义惠更斯-菲涅耳原理,推导出了部分相干平顶光束通过大气湍流传输的空间相干度公式,研究了湍流对光束空间相干特性的影响.研究表明:部分相干平顶光束的空间相干性由大气湍流折射率结构常数、光束的相对空间相关长度、平顶光束的阶数、传输距离和观察点位置坐标等因素共同确定.部分相干平顶光束通过湍流大气传输时,其空间相干度会出现振荡和相位奇异现象,但随着湍流的增强,振荡减弱,直至振荡和相位奇异现象消失.     

纳米ZnO薄膜的反射及偏振特性研究

用电子束蒸发镀膜法制备了纳米ZnO薄膜．通过测量其X射线衍射谱,计算出纳米ZnO颗粒的平均粒径大小为30nm．实验研究了纳米ZnO薄膜的反射和偏振性质,结果表明：当振动方向平行于入射面的线偏振光（简称P光）入射纳米ZnO薄膜时,不存在严格意义上的布儒斯特角,但对于入射角却存在一个临界角β．当入射角小于β时,反射光的振动面随着入射角的增大向左旋转;当入射角大于β时,振动面转而向右旋转;当振动方向垂直于入射面的线偏振光（简称S光）入射纳米ZnO薄膜时,反射光的振动面始终向左旋转．     

利用遗传算法设计可见光波段全能反射器

介绍了遗传算法在设计宽频带全能反射器中的应用.设计的关键是通过遗传算法寻找到不同一维准周期光子晶体间的最佳组合方式以及光学厚度以便形成一个光子晶体异质结.利用传输矩阵法分析了一维准周期系统中的电磁传输特性.计算结果表明,准周期光子晶体的全方向反射带宽受晶胞单元以及周期数的影响.根据这些规律,用遗传算法成功地优化了光子晶体异质结的结构并得到两种适用于可见光波段的高性能全能反射器.例如结构为(HLLHL)13(HL)13( LHL)15 ［注: nL=1.46,nH=2.6,dL=0.218λ0/nL且dH=0.201λ0/nH］的反射器在可见光波段内的全方向反射带宽达到了88.42% (446 nm~779 nm).     

Design of periodic metal-insulator-metal waveguide back structures for the enhancement of light absorption in thin-film solar cells

To increase the absorption in a thin layer of absorbing material (amorphous silicon, a-Si), a light trapping design is presented. The designed structure incorporates periodic metal-insulator-metal waveguides to enhance the optical path length of light within the solar cells. The new design can result in broadband optical absorption enhancement not only for transverse magnetic (TM)-polarized light, but also for transverse electric (TE)-polarized light. No plasmonic modes can be excited in TE-polarization, but because of the coupling into the a-Si planar waveguide guiding modes and the diffraction of light by the bottom periodic structures into higher diffraction orders, the total absorption in the active region is also increased. The results from rigorous coupled wave analysis show that the overall optical absorption in the active layer can be greatly enhanced by up to 40%. The designed structures presented in this paper can be integrated with back contact technology to potentially produce high-efficiency thin-film solar cell devices.     

CO_2激光器混沌运转的实验方法

从M B方程出发 ,简单分析了CO2 激光器的动力学过程。从实验角度对实现CO2 激光器混沌运转的各种方法作了概述 ,并结合多电极对CO2 激光器提出了可行的实现混沌的方法     

金属目标后向散射特性与表面温度场关系的研究

本文研究金属目标的后向散射特性与入射角、表面温度场之间的关系。根据现有条件设计了实验装置,并用该装置测量了部分实验数据。相关结论对激光探测等领域的研究具有一定的参考价值。