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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.

FEM Simulations of Rod-Type Photonic Crystal Slabs as Resonant Microsystems for Optical Gas Sensors

C. Kraeh, and H. Hedler
Siemens AG, Munich
Munich, Germany

We are developing a solid state gas sensor that combines a small form factor with the high sensitivity of optical gas detection. The gas sensor is based on an optical resonant microsystem that is penetrated by gas molecules. This microsystem consists of an array of vertical rods in air forming a photonic crystal. Light propagates through the photonic crystal along a line defect waveguide. For ...

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 ...

Designing a Smart Skin with Fractal Geometry

S. Ni, C. Yang Koh, S. Kooi, and E. Thomas
Institute for Soldier Nanotechnologies
Dept. of Materials Science and Eng.
MIT
Cambridge, MA

Recently, the concepts of fractal geometry have been introduced into electromagnetic and plasmonic metamaterials. With their self-similarity, structures based on fractal geometry should exhibit multi-band character with high Q factors due to the scaling law. However, there exist few studies of phononic metamaterials having fractal geometry. COMSOL is used to investigate vector elastic and ...

Design of Tunable Metamaterial Operating Near 90 GHz

K. Tarnowski[1], W. Salejda[1]
[1]Institute of Physics, Wroclaw University of Technology, Wroclaw, Poland

Currently there is much interest in electromagnetic metamaterials [1-9]. In our work we have focused on design of tunable metamaterial which can be made within available technology. In proposed design we use metallic split-ring resonators and thin-wires (Figure 1). Moreover we have decided to introduce nematic liquid crystal layer in design to obtain tunability (Figure 2). One can control ...

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 ...

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 ...

Theoretical Study Of Porous Silicon Waveguides And Their Applicability For Vapour Sensing

T. Hutter[1], N. Bamiedakis[2], and S. Elliott[1]
[1]Department of Chemistry, University of Cambridge, UK
[2]Centre for Advanced Photonics and Electronics, Engineering Department, University of Cambridge, UK

The finite-element method (FEM) (COMSOL RF Module) has been employed for modal analyses of porous silicon (PSi) waveguides composed of a guiding layer of low porosity (high refractive index) on a cladding layer with higher porosity (lower refractive index). These can be made by switching the current density from a lower to a higher value during the electrochemical etching process. The ...

TM Wave Propagation in Optical Nanostructures with a Third-Order Nonlinear Response: Modeling and Validation with COMSOL

A. Kildishev[1], E. E. Narimanov[1]
[1]Birck Nanotechnology Center, School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana, USA

An enhanced method is used for analysis of third-order nonlinearities in optical nanostructures with scalar TM (H-field) frequency domain formulation. After embedding it in COMSOL Multiphysics it is shown to produce fast and accurate results without superfluous vector E-field formalism. A standard TM representation based on cubic non-linear susceptibility χ(3) results in an intractable ...

FE Modeling of Surfaces with Realistic 3D Roughness: Roughness Effects in Optics of Plasmonic Nanoantennas

J. Borneman[1], A. Kildishev[1], K. Chen[1], and V. Drachev[1]

[1]School of Electrical and Computer Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana, USA

COMSOL Multiphysics has been widely used to model the near and far-field electromagnetics (specifically, transmission and reflection spectra) of gold and silver nanoantenna arrays. We use a moving 3D mesh, thus preserving the DOF number and simply morphing the structure of the mesh to accommodate the moving boundary. The electromagnetics model consist of four multiphysics models, two ...

Super-resolving Properties of Metallodielectric Stacks

N. Katte[1], J. Haus[1], J.B. Serushema[1], and M. Scalora[2]
[1]University of Dayton, Dayton, OH, USA
[2]Charles M. Bowden Research Center, Redstone Arsenal, AL, USA

We show that diffraction can be suppressed in a one-dimensional metallodielectric stack (MDS) at visible wavelengths to achieve super-resolution imaging. In our calculations we use two popular techniques, which can be adapted to investigate the imaging properties of MDSs. The two methods are the transfer matrix method (TMM) and the Finite element method based software, COMSOL Multiphysics. The ...