Here you will find presentations given at COMSOL Conferences around the globe. The presentations explore the innovative research and products designed by your peers using COMSOL Multiphysics. Research topics span a wide array of industries and application areas, including the electrical, mechanical, fluid, and chemical disciplines. Use the Quick Search to find presentations pertaining to your application area.
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太赫兹声子极化激元的产生及与金属天线的相互作用

吴强 [1], 潘崇佩 [1], 张琦 [1],
[1] 南开大学,天津,中国

“极化激元”是固体物理学中的重要概念,泛指各种极性元激发与光子的耦合。其中,声子极化激元是指晶格振动的声子与电磁场中的光子相互耦合的一种极化激元波。使用飞秒光在铁电晶体铌酸锂中通过光学非线性效应可产生声子极化激元,其频率位于太赫兹波段,在晶格的振动弛豫、太赫兹光谱、与介观微结构作用等领域已有广泛应用。 声子极化激元涉及电磁场和晶格场的耦合问题,其形式满足黄昆方程。我们使用 COMSOL Multiphysics® 的多物理场(偏微分方程组以及射频模块)模拟了块状铌酸锂晶体中产生声子极化激元波的产生和传输。 铌酸锂晶体作为太赫兹应用的集成化平台,可通过在平板波导上引入微结构实现对太赫兹波的调控。诸多手段中,太赫兹天线作为电磁场的传播场与局域场转换的关键部件,对太赫兹通信和太赫兹光谱等领域都有不可替代的作用。基于这一点,我们设计了一种尖端相对的棒状天线结构,使用 COMSOL ...

电晕放电紫外光谱仿真与测量

庾金涛 [1], 李清灵 [1], 房陈岩 [1],
[1] 中科院上海技术物理研究所,上海,中国

随着我国国民经济的持续高速发展,生活与生产的用电量越来越大,电力行业的规模日益增大。电力设备在不正常工作时,大多会产生电弧电晕,通过检测电晕电弧等目标,就可以获知电力系统设备的损害程度。然而,目前并没有对真实的电弧电晕目标进行非光子计数方式的定量化研究。本文作者研制了一套紫外外波段的面阵成像探测系统,对实验室人工制造的高电压电弧电晕目标进行了相关的分析与实验研究。 利用 COMSOL Multiphysics® 的等离子体物理场接口的 DC 放电接口,对实验所用的天梯仪器的放电行为建模,分子碰撞数据选择大气压下的空气模型,对电晕放电辉光主要贡献的成分N2+,进行密度分布计算,结果换算成光强,得到定性的光强分布,与相机拍摄结果对比。 自制的一套紫外面阵成像系统,对由实验室高压设备在空气中产生的电弧电晕目标开展了紫外成像实验,对电弧电晕目标在 200-1000nm ...

Metamaterial Based Patch Antenna with Broad Bandwidth Designed by COMSOL Multiphysics® Software

李学识 [1], 郑李娟 [1],
[1] 广东工业大学,广州,中国

A patch antenna based on metamaterials of composite split-ring-resonators (CSRRs) and strip gaps is designed with COMSOL Multiphysics® software. The antenna is constructed by using CSRR structures in forms of circular rings on the patch and employing strip gaps on the ground plane. The signal is fed by a common microstrip line that connects the patch and the input port. The antenna is based on a ...

The Effect of Space Charge due to the Auto-Ionization of Neutral, Hydrogenic States in Point-Contact Germanium Detectors at MilliKelvin Temperatures - new

D. Faiez[1], N. Mirabolfathi[1], B. Sadoulet[1], K. M. Sundqvist[2]
[1]Department of Physics, University of California - Berkeley, Berkeley, CA, USA
[2]Department of Electrical & Computer Engineering, Texas A&M University, College Station, TX, USA

A class of semiconducting detectors, operated at temperature T~50mK, has direct application to the search for dark matter particle, when are able to simultaneously measure both the ionization and phonons created by particle interactions. We explore the effect of space charge accumulation in a germanium p-type point contact detector which arises due to the auto-ionization of hydrogenic ...

Time-Resolved Optical Tomography in Preclinical Studies: Propagation of Excitation and Fluorescence Photons.

F. Nouizi[1], R. Chabrier[1], M. Torregrossa[2], and P. Poulet[1]
[1]Laboratoire d’Imagerie et de Neurosciences Cognitives, Straßbourg, France
[2]Laboratoire des Sciences de l'Image, de l'Informatique et de la Télédétection, France

We present time-resolved methods that rely on near-infrared photons to image the optical properties and distribution of fluorescent probes in small laboratory animals. The coupled diffusion equations of excitation and fluorescence photons in highly scattering tissues were solved using the three-dimensional Finite Element Method (FEM) provided by COMSOL. The computed results allowed to yield ...

Finite Element Analysis of Integrated Circuit Interconnect Lines on Lossy Silicon Substrate

S. Musa[1], M. Sadiku[1], and A. Emam[2]

[1]Roy G. Perry College of Engineering, Prairie View A&M University, Prairie View, TX
[2]Information Systems Department, King Saud University, Riyadh, Saudi Arabia

The silicon substrate has a significant effect on the inductance parameter of a lossy interconnect line on an integrated circuit. It is essential to take this into account in determining the transmission line electrical parameters. In this paper, a new quasi-TEM capacitance and inductance analysis of multiconductor multilayer interconnects is successfully demonstrated using the finite element ...

Coupling Picosecond Terahertz Pulses to a Scanning Tunneling Microscope

P. H. Nguyen [1], C. Rathje [2], G. J. Hornig [1], V. Jelic [1], C. Ropers [2], F. A. Hegmann [1],
[1] University of Alberta, Edmonton, AB, Canada
[2] 4th Physical Institute, University of Göttingen, Göttingen, Germany

Probing ultrafast processes over subpicosecond and picosecond time scales provides fundamental insight into the nature of materials. We have experimentally demonstrated terahertz (THz)-pulse-induced tunneling in a scanning tunneling microscope (THz-STM) to image surfaces with simultaneous nanometer spatial resolution and subpicosecond time resolution [1]. However, the exact mechanism by which ...

Optimizing the Fluorescence of Diamond Color Centers Encapsulated into Core-Shell Nano-Resonators

M. Csete [1], L. Z. Szabó [1], A. Szenes [1], B. Bánhelyi [2], T. Csendes [2], G. Szabó [1]
[1] Department of Optics and Quantum Electronics, University of Szeged, Szeged, Hungary
[2] Institute of Informatics, University of Szeged, Szeged, Hungary

INTRODUCTION Enhancement of a single-photon emission is a great demand in recent science and applications, including development novel class of light sources, encoded information transfer and biological imaging [1, 2, 3]. Fluorescence can be improved through excitation and emission enhancement. Improvement of these two processes can be realized by using the near-field enhancement accompanying ...

A Reliable Approach to Estimate Surface-enhanced Raman Scattering Intensity of Metal Nanostructures

En-Ming You [1], Jun Yi [1], Song-Yuan Ding [1,2],
[1] State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China
[2] Collaborative Innovation Center of Chemistry for Energy Materials, Xiamen University, Xiamen, China

Surface-enhanced Raman scattering (SERS) is a fingerprint spectroscopy whose sensitivity is down to single molecule level. The mechanism of SERS is mainly contributed to huge enhancement of local electric field, which originated from surface plasmon resonance of metal nanostructures. It is very important to exactly calculate the local enhancement in the electric field strength for right ...

An All-Purpose Full-Vectorial Finite Element Model for Arbitrarily Shaped Crossed-Gratings

G. Demésy[1], F. Zolla[1], A. Nicolet[1], and M. Commandré[1]
[1]Institut Fresnel, Université Aix-Marseille III, École Centrale de Marseille, France

We demonstrate the accuracy of the Finite Element Method (FEM) to characterize an arbitrarily shaped crossed-grating in a multilayered stack illuminated by an arbitrarily polarized plane wave under oblique incidence. To our knowledge, this is the first time that 3D diffraction efficiencies are calculated using the FEM. The method has been validated using classical cases found in the literature. ...