Fabrication of Alumina Films with Three-Dimensional Ordered Macropores by Self-Assembly of Binary Colloidal Spheres

We present a new process to obtain a three-dimensional ordered macroporous structure (3DOM). The 3DOM films were fabricated using a coassembly of monodispersed polystyrene spheres and alumina hydroxide sols in aqueous suspensions on a vertical substrate followed by a calcination treatment. The 3DOM film structure, quality and morphology have been characterized by scanning electron microscopy and transmission spectra.     

PbCl2分子的光解离

用YAG激光的四次谐波光解离PbCl₂分子。实验确认了这种光解过程是双光子过程。通过对激光诱导荧光的测量,发现这一光解过程造成了Pb原子的亚稳态6p^{2 3}P₂与基态6p^{2 3}P。间的粒子数反分布。同时观察到基于6p^{2 3}P₂能级的受激共振辐射及受激喇曼散射。 关键词：     

光镊系统中微小颗粒的位移和所受力的测量

利用高稳定度的并配备了高精度位移和力测量装置的光镊系统，实现了对微米颗粒的纳米量级的位移和所受皮牛顿量级的力的定量测量.     

面向第三世界的几个国际性科学组织

本文介绍了主要由意大利政府资助和支持的三个国际性科学组织：国际理论物理中心（ＩＣＰＰ）、第三世界科学院（ＴＷＡＳ）、国际科学和高技术中心（ＩＣＳ）．第三世界国家的科学工作者根据需要，可以向这三个组织申请资助，以开展有关的科学交流和研究活动。     

光解产生的铅原子中受激喇曼散射和共振激光辐射

用2660(?)的紫外激光解离PbCl_2分子时,发现在3740(?)和3734(?)波长上有较强的受激辐射输出.根据它们的光谱特性和铅原子的能级结构判断,这些辐射是基于双光子解离PbCl_2分子得到的铅原子在6p~(23)P_2亚稳能级上的布居而产生的光泵共振激光辐射和受激喇曼散射.提出了描述整个过程的理论模型,通过拟合实验结果,确定了2660(?)激光双光子解离PbCl_2产生6p~(23)P_2亚稳态铅原子的光解系数.当PbCl_2分子密度为N_(00)=6.21×10~(16)cm~(-3)时,光解产生的铅原子在6p~(23)P_2和6p~(21)D_2这两个亚稳态的最大布居数近似相等,称为2.0×10~(16)cm~(-3).     

如何向纯粹与应用物理国际联合会申请举办国际会议

1.IUPAP简介 纯粹与应用物理国际联合会(简称IUPAP)是一国际性的学术团体,由三十四个国家物理机构的代表组成,每三年召开一次代表大会.代表大会选举产生执委会委员和各专业委员会委员.执委会负责日常事务,通常每年召开一次执委会议. IUPAP下设18个专业委员会,分别是: C_2──符号、单位、名词、原子质量和基本常数委员会; C_3──热力学和统计力学专业委员会; C_4──字苗射线专业委员会; C_5──低温物理专业委员会; C_6──出版专业委员会; C_8──半导体专业委员会; C_9──磁学专业委员会; C_(10)──凝聚态结构和动力学专业…     

Controlling the focusing properties of a triangular-lattice metallic photonic-crystal slab：

This paper studies the focusing properties of a two-dimensional photonic crystal (PC) slab consisting of a triangular lattice of metallic cylinders immersed in a dielectric background. Through the analysis of the equifrequency-surface contours and the field patterns of a point source placed in the vicinity of the PC slab, it finds that both the image distance and image quality can be controlled by simply adjusting the refractive index of the background material.     

Optical properties of the direct-coupled Y-branch filtersby using photonic crystal slabs

We fabricated a new type of two-dimensional photonic crystal slab filter. The resonant cavities were directly put into the waveguide arms. The optical transmissions of the filters were measured and the results show that the optimized two-channel filters give good intensity distribution at the output ports of the waveguide. A minimum wavelength spacing of 5~nm of the filter outputs isrealized by accurately controlling the size of the resonant cavities.     

Near-field imaging of a square-lattice metallic photonic-crystal slab at the second band

Imaging properties of a two-dimensional photonic crystal slab lens are investigated through the finite-difference time-domain method. In this paper, we consider the photonic crystal slab consisting of a square lattice of square metallic rods immersed in a dielectric background. Through the analysis of the equifrequency-surface contours and the field patterns of a point source placed in the vicinity of the photonic crystal slab, we find that a good-quality image can form at the frequencies in the second TM-polarized photonic band. Comparing the images formed at different frequencies, we can clearly see that an excellent-quality image is formed by the mechanisms of simultaneous action of the self-collimation effect and the negative-refraction effect.     

光子晶体中双通道之间能量的转移

从理论和实验上分析了光子晶体中双通道之间能量的转移.在双通道之间引入复合型光子晶体波导,通过调节复合型波导的内部参数，使其满足一定的条件，就可以实现双通道之间能量的完全转移，从而实现了光的定向传输.在实验中，测得了输出端的透过谱. 关键词： 复合型光子晶体波导 能量转移 定向传输