【作品名称】大霹雳
【参赛作者】赵嬿钧   陈政营   林怡瑞   戴育安 

【作品说明】

艺术性：

强而有力且令人惊艳的散射状，让人联想起宇宙的发展，是否始于这神奇微小的结构中呢？

实物说明：

此结构为ZnO奈米线球，可以看出ZnO放射状的结构。此奈米线成长的方向为压电性最强的c轴方向。 

Modal Characteristics of Antiresonant Reflecting Pipe Waveguides for Terahertz Waveguiding

Professor Hung-chun Chang

Graduate Institute of Photonics and Optoelectronics, National Taiwan University

台湾大学光电所 张宏钧教授

The pipe waveguide, which is a thin pipe consisting of a large air core and a thin dielectric layer with uniform but low index, is promising for THz waveguiding owing to its low-loss feature and simple structure. In this research, modal characteristics of the leaky core modes of the pipe waveguide are investigated in the THz range. Utilizing the finite-difference frequency-domain (FDFD) mode solver, modal indices and attenuation constants of the core modes which are frequency dependent are calculated for different core diameters, cladding thicknesses, and cladding refractive indices. It is found that at certain frequencies no core modes can exist. Comparing these frequencies with the resonant frequencies of the cladding reveals that the guiding mechanism of the core modes is that of the antiresonant reflecting guiding. Calculated results also suggest that, to have a low-loss and high-bandwidth pipe waveguide, large core diameter, thin cladding thickness, and low refractive index are desired. The effect of material absorption is also examined, which shows that the attenuation constant magnitude will be increased and the increment is more significant at higher frequencies. Moreover, modal patterns are shown for the fundamental mode and the higher order modes, including modal intensity distributions and electric field vector distributions. It is observed that modal patterns of the core modes of the pipe waveguide resemble those of the guided modes of the step-index fiber. From the spectrum of the attenuation constant, it shows that the fundamental mode (HE₁₁-like) has the smallest attenuation constant and is the dominant mode for the pipe waveguide investigated. (Optics Express, vol. 18, no. 1, pp. 309–322, 5 January 2010.)

Fabrication of Sphere-like Au Nanoparticles with Laser Irradiation for Localized Surface Plasmon Resonance Applications

Professor C. C. Yang’s Laboratory

Graduate Institute of Photonics and Optoelectronics, National Taiwan University

台湾大学光电所 杨志忠教授

We have demonstrated a simple method for fabricating substrate adhesive Au nanoparticles (NPs) of no aggregation based on a process of laser ablation and annealing. The size, shape, surface density, and coverage of Au NPs on a substrate can be controlled by laser energy density, substrate material and surface condition, deposited Au film thickness, and the liquid covering the Au film during laser irradiation. With optical transmission measurements, the in-plane and out-of-plane localized surface plasmon resonance (LSPR) features can be clearly identified due to the similar shapes and vertical alignments of NPs on substrate. The spectral features of substrate-affected LSPR modes rely on the size, Au/substrate contact area, substrate material, and surrounding gas or liquid. Numerical simulations based on the finite-element method show highly consistent results in the LSPR-induced extinction spectral features. Fig. 1 and 2 show the plan- and tilted-view SEM images of Au NPs on a sapphire substrate. Fig. 3 shows the transmission spectra of Au NPs on sapphire and SiO₂ demonstrating the LSPR features. For details, please read the publication: C. Y. Chen et al., Optics Express 17, 14186 (2009).

本篇论文主要使用氮化镓奈米柱接合再生长的方式来减少线差排(threading dislocation)密度。进行方式为：在传统的氮化镓基板上，用奈米压印的方式于表面上制作出周期性孔洞的二氧化硅，再使用脉冲成长模态 (pulsed growth mode)于有机金属气相沉积的环境下成长高质量之氮化镓奈米柱，再将成长模态转换至二维成长模态进行接合再生长。图一为接合再生长之氮化镓基板之扫描式电子显微镜(scanning electron microscopy)横截面影像，并且在原子力显微镜(atomic force microscopy)、穿透式电子显微镜(transmission electron microscopy)、深度解析X光绕射(depth-dependent X-ray diffraction)、变温光激发荧光(temperature-dependent photoluminescence)等量测中，都显示出此一基板之各项性质都比传统基板更为优越。图二为电激发荧光(electroluminescence)量测结果，于此基板上成长之蓝光发光二极管比成长于传统基板之发光二极管增加约百分之八十的发光强度。

图一、印在一层薄塑料板上、绕着手指的微型LED显示器。

图二、微型化LED制程步骤。

图三、 可延展的微型LED，印制出来的微型LED相连成一张网，并附着在一个橡胶底层上。