Technical Papers and Presentations

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.

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 ...

Thickness Designs for Micro-Thermoelectric Generators Using Three Dimensional PDE Coefficient-COMSOL Multiphysics 4.2a Analysis

S. Seif[1], K. Cadien[1]
[1]Department of Chemical & Materials Engineering, University of Alberta, Edmonton, AB, Canada

Predicting the optimum thickness and gap size between n-type and p-type legs of micro thermoelectric devices are the major challenges in designing micro thermo electric generators. We have reported the gap size and optimal thickness for optimal output power. We found that the gap size should be 0.1 microns; but, depending on fabrication capability, the gap size can be varied from 0.1 to 6 ...

Heterodimensional Charge-Carrier Confinement in Sub-Monolayer InAs in GaAs - new

S. Harrison[1], M. Young[1], M. Hayne[1], P. D. Hodgson[1], R. J. Young[1], A. Strittmatter[2], A. Lenz[2], U. W. Pohl[2], D. Bimberg[2]
[1]Department of Physics, Lancaster University, Lancaster, UK
[2]Institut für Festkörperphysik, Berlin, Germany

Low-dimensional semiconductor nanostructures, in which charge carriers are confined in a number of spatial dimensions, are the focus of much solid-state physics research, offering superior optical and electronic properties over their bulk counterparts. Both two-dimensional (2D) and zero-dimensional (0D) structures have seen wide-ranging applications in laser diodes, solar cells and LEDs to name ...

Optimization of Micro-Structured Waveguides in Lithium Niobate (Z-Cut) - new

H. Karakuzu[1], M. Dubov[1], S. Boscolo[1]
[1] Aston University, Birmingham, UK

We present an optimization procedure to improve the propagation properties of the depressed-cladding, buried micro-structured waveguides formed in a z-cut lithium niobate (LN) crystal by high repetition rate femtosecond (fs) laser writing. It is shown that the propagation wavelength for which the confinement losses of ordinary (O) and extraordinary ordinary (E) polarizations are below 1 dB/cm ...

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 ...

Going beyond Axisymmetry: 2.5D Vector Electromagnetics

Y.A. Urzhumov[1][,][2], N.I. Landy[1][,][2], C. Ciraci[2], D.R. Smith[1][,][2]
[1]Department of Electrical and Computer Engineering, Pratt School of Engineering, Duke University, Durham, NC, USA
[2]Center for Metamaterials and Integrated Plasmonics, Pratt School of Engineering, Duke University, Durham, NC, USA

Linear wave propagation through inhomogeneous structures of size R?? (Fig.1) is a computationally challenging problem, in particular when using finite element methods, due to the steep increase of the number of degrees of freedom as a function of R/?. Fortunately, when the geometry of the problem possesses symmetries, one may choose an appropriate basis in which the stiffness matrix of the ...

Modelling Ultra-short Pulse Laser Ablation of Dielectric Materials Using multiple Rate Equations - new

P. Boerner[1], K. Wegener[1]
[1]Institute of Machine Tools and Manufacturing, ETH Zurich, Zurich, Switzerland

Ultrafast lasers are widely applied in micromachining, material science and physics. In industry, picosecond lasers are becoming more and more established. For pulse lengths shorter than the electron-phonon coupling time, heat affected zones are negligible. Thermally sensitive materials can be processed using ultrashort pulse laser radiation. Multi-component materials and poorly absorbing ...

Solving the Paraxial Wave Equation using COMSOL

P. Mikulski, K. Mcilhany, and R. Malek-Madani
United States Naval Academy
Annapolis, MD

Here we present and discuss numerical solutions to the paraxial wave equation using COMSOL (2D, PDE, General Form, time-dependent analysis). Ultimately, the goal is to extend this treatment of free-space beam propagation to the case of propagation through a medium that is non-uniform and subject to non-linear effects where the beam itself is modifying the properties of the medium in which it is ...

Complex K-Bands Calculation for Plasmonic Crystal Slabs by Means of Weak Formulation of Helmholtz's Eigenvalue Equation

G. Parisi[1], P. Zilio[1], F. Romanato[1]
[1]University of Padova, Padova, Italy

We present a Finite Element Method (FEM) to calculate the complex valued k(?) dispersion curves of a photonic crystal slab in presence of both dispersive and lossy materials. In particular the method can be exploited to study plasmonic crystal slabs. We adopt Perfectly Matched Layers (PMLs) in order to truncate the open boundaries of the model, including their related anisotropic permittivity and ...

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 ...

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