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.

Modeling Mechanical Deformation and Optical Waveguiding Properties of Ion-Implanted Diamond

F. Bosia[1], P. Olivero[2], and E. Vittone[2]
[1]Dipartimento di Fisica Teorica, Università di Torino, Torino, Italy
[2]Dipartimento di Fisica Sperimentale, Università di Torino, Torino, Italy

Ion implantation in insulating materials leads to local variations in mechanical and optical properties that can be exploited for the fabrication of micro-structures. In particular, ion irradiation of diamond causes the formation of buried amorphised layers, with correspondent mass density and refractive index variations that depend on the level of “damage” of the crystal structure. ...

Modeling VRALA,The Next-Generation Actuator For High-Density, Tick Secondary Mirrors For Astronomy

C. Del Vecchio[1], G. Agapito[1], G. Tomassi[2], and E. De Santis[2]
[1]National Institute for Astrophysics, Arcetri Astrophysical Observatory, Firenze, Italy
[2]University of Cassino, Cassino, Italy

The next-generation of Extremely Large Telescopes adaptive optics systems require high-order, long-stroke, quite large deformable mirrors. Higher forces and greater actuator densities than the ones provided by the current technology are needed, still maintaining the severe accuracy and bandwidth requests. Based on a very simple magnetic circuit, providing a compact device, the VRALA actuator ...

Impulsive Thermomechanics of hypersonic surface phononic crystals

F. Banfi[1], D. Nardi[2], and M. Travagliati[3]
[1]Dipartimento Matematica e Fisica, Università Cattolica, Brescia, Italy
[2]JILA, University of Colorado at Boulder, Boulder, Colorado, United States
[3]Center for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Pisa, Italy

Ultrafast optical generation of pseudosurface acoustic waves is investigated in hypersonic surface phononic crystals. The thermomechanics is modeled from first-principles to follow the initial impulsive heat-driven displacement in the time domain. Spectral decomposition of the displacement over the surface phononic crystal eigenmodes outlines asymmetric resonances featuring the coupling between ...

Reconstruction for Interstitial Diffuse Optical Tomography (iDOT) for Human Prostate

X. Liang, K. Kang-Hsin Wang, and T. Zhu
University of Pennsylvania
Philadelphia, PA

Determination of tissue optical properties distributions is very important for determining light fluence distribution during photodynamic therapy (PDT). In this study, an interstitial diffuse optical tomography (iDOT) system was used to characterize the spatial distribution of optical properties for a series of mathematical phantoms as well as verification measurements in a prostate ...

Antenna and Plasmonic Properties of Scanning Probe Tips at Optical and Terahertz Regimes

A. Haidary[1], P. Grütter[1], Y. Miyahara[1]
[1]Physics Department, McGill University, Montreal, QC, Canada

A wide variety of near-field optical phenomena such as apertureless near-field scanning microscopy (ANSM) at optical and terahertz (THz) regimes and surface enhanced Raman scattering relies on the electric field enhancement at the end of a sharp tip. Achieving and controlling this electric field enhancement is a key challenge for a wide range of applications such as surface modification, data ...

Non-Equilibrium Quantum Well Populations and Optical Characteristics of III-Nitride Lasers and Light-Emitting Diodes

M. Kisin, and H. El-Ghoroury
Ostendo Technologies, Inc.
Carlsbad, CA

COMSOL-based Ostendo’s Optoelectronic Device Modeling Software (ODMS) has been updated to include effects of non-equilibrium QW populations in semiconductor light-emitting and laser diodes. III-nitride light emitters with different levels of polarity have been compared as an illustrative example of ODMS performance. Modeling proved that high intra-QW recombination rates in III-nitride light ...

Modeling transport in silicon nanocrystal structure

Leroy, Y., Leriche, B., Cordan, A.S.
InESS — ENSPS, UMR 7163, ILLKIRCH, France

We present in this paper a model to study new memory devices with embedded nanocrystals, emerging in microelectronics. The theoretical calculations and their implementation in FEMLAB are detailed, leading to a quite simple and realistic model. One key point for these memories is the electronic tunnel transfer to store the charge into a nanocrystal. This is why we carry out a brief analysis of ...

Numerical Simulation of Thermal Runaway in a THz GaAs Photoconductor

S. Sarodia[1,2], W. Zhang[2], E. Brown[2]
[1]Centerville High School, Dayton, OH, USA
[2]Wright State University, Dayton, OH, USA

Ultrafast terahertz photoconductor devices, especially photomixers, are usually limited in output power by device failure thought to be caused by excessive temperatures. Therefore, understanding of thermal breakdown is essential to the study of device reliability and failure of photoconductors. We performed a series of simulations to determine the electronic and thermal thresholds responsible ...

Enhanced Surface Plasmon Polariton Propagation Induced by Active Dielectrics

M. Mattheakis[1], C. Athanasopoulos[1], G. P. Tsironis[1]
[1]University of Crete, Heraklion, Greece

We present numerical simulations for the propagation of surface plasmon polaritons in a dielectric-metal-dielectric waveguide using COMSOL Multiphysics® software. We show that the use of an active dielectric with gain that compensates metal absorption losses enhances substantially plasmon propagation. Furthermore, the introduction of the active material induces, for a specific gain value, a ...

Methods to Optimize Plasmonic Structure Integrated Single-Photon Detector Designs

M. Csete[1], G. Szekeres[1], B. Banhelyi[2], A. Szenes[1], T. Csendes[2], G. Szabo[1]
[1]Department of Optics and Quantum Electronics, University of Szeged, Szeged, Hungary
[2]Department of Computational Optimization, University of Szeged, Szeged, Hungary

Introduction: Predesigned plasmonic structures are capable of enhancing optical phenomena, the key concept is tailoring the integrated devices' composition to engineer the spectral response and near-field distribution [1]. Our previous studies have shown that three-quarter-wavelength periodic plasmonic structures are capable of improving single-photon detection efficiency [2, 3]. Parametric sweep ...

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