Systematic study on visible light collimation nanostructured slits in the metal surface

We present a systematic experimental investigation on visible light collimation by a nanostructured slit flanked with a pair of periodic array of grooves in gold thin film. A wide variety of aspects are considered, such as the polarization state, the transport path of incident light, the groove-groove spacing, the groove width and depth. Our results clearly show that the relationship between the collimation wavelength and the periodicity of the slit-groove structure accords well with the surface plasmon dispersion model proposed by previous researchers. Furthermore, the surface plasmon wave phase retardation effect induced by the surface structure is also verified via the measurement for samples with different groove widths and depths. These results indicate that the detailed geometry of the groove structure has obvious impacts on the collimation effect and the angular distribution of the diffraction light in the subwavelength plasmonic system.     

曝光强度对卤化银微晶中载流子行为及其陷阱效应的影响

针对卤化银感光材料潜影形成过程中光作用动力学问题,分析了曝光强度对光生载流子行为和电子陷阱效应的影响,认为伴随着曝光强度的增加,影响光电子衰减的因素由电子陷阱起主要作用演化到电子陷阱和复合中心共同起作用进而演化到复合中心起主要作用.     

十二重准晶中的方向缺陷

采用多重散射的方法研究了十二重准晶中的缺陷模,发现在十二重准晶中存在方向缺陷,且当缺陷组合围绕对称中心旋转时,在保持原有缺陷模的基础上,出现了新的缺陷模. 关键词： 准晶 缺陷 带隙     

The influence of K4Fe（CN）6 on the photosensitivity of cubic AgCl microcrystal

The influence of K4Fe(CN)6 at various doping concentrations on the photosensitivity of cubic AgC1 microcrysgals has been investigated by using the microwave absorption and phase-sensitive measurement technique. The time behaviour of free photoelectrons in AgCl microcrystals is analysed by using computer simulation as a function of three parameters of shallow electron trap (SET) including doping concentration, trap depth and capture cross-section (CCS).It is found that the three parameters of SET play different roles on the free photoelectron decay time (FDT). After considering the threshold effects of the three parameters and their collective effects, the trap depth value, the CCS value,and the optimal doping concentration of the SET introduced by the dopant K4Fe(CN)6 in cubic AgCl microcrystals can also be determined, and the best photosensitivity of cubic AgCl can be obtained.     

The influence of trapping centres on the photoelectron decay in silver halide

Photoelectron is the foundation of latent image formation, the decay process of photoelectrons is influenced by all kinds of trapping centres in silver halide. By analysing the mechanism of latent image formation it is found that electron trap, hole trap, and one kind of recombination centre where free electron and trapped hole recombine are the main trapping centres in silver halide. Different trapping centres have different influences on the photoelectron behaviour. The effects of all kinds of typical trapping centres on the decay of photoelectrons are systematically investigated by solving the photoelectron decay kinetic equations. The results are in agreement with those obtained in the microwave absorption dielectric spectrum experiment.     

Systematic study on visible light collimation by nanostructured slits in the metal surface

We present a systematic experimental investigation on visible light collimation by a nanostructured slit flanked with a pair of periodic array of grooves in gold thin film. A wide variety of aspects are considered, such as the polarization state, the transport path of incident light, the groove--groove spacing, the groove width and depth. Our results clearly show that the relationship between the collimation wavelength and the periodicity of the slit-groove structure accords well with the surface plasmon dispersion model proposed by previous researchers. Furthermore, the surface plasmon wave phase retardation effect induced by the surface structure is also verified via the measurement for samples with different groove widths and depths. These results indicate that the detailed geometry of the groove structure has obvious impacts on the collimation effect and the angular distribution of the diffraction light in the subwavelength plasmonic system.     

硫增感AgBrCl立方体微晶中光电子衰减行为的研究

利用微波吸收相敏检测技术并结合短脉冲激光曝光,测量了硫增感条件下AgBrCl立方体微晶感光材料的光电子时间衰减谱.分析了光电子一级衰减区域与增感温度的关系,确定了硫增感的陷阱效应对光电子衰减时间和光电子不同一级衰减区域的影响,并获得了增感过程中生成浅电子陷阱效果的最佳增感条件.     

The influence of hole shape on enhancing transmission through subwavelength hole arrays

The extraordinary light transmission through a 200-nm thick gold film when passing through different subwavelength hole arrays is observed experimentally. The sample is fabricated by electron beam lithography and reactive ion etching system. A comparison between light transmissions shows that the hole shape changing from rectangular to diamond strongly affects the transmission intensity although both structures possess the same lattice constant of 600,nm. Moreover, the position of the transmission maximum undergoes a spectral red-shift of about 63,nm. Numerical simulations by using a transfer matrix method reproduce the observed transmission spectrum quite well.