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.

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 ...

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 ...

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 ...

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 ...

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 ...

Optical Manipulation of Microscopic Objects

R. Ozawa
Yokohama University
Japan

In recent years, optical manipulation using optical radiation pressure has been widely studied. In this study, the radiation pressure exerted on various kinds of microscopic objects with different laser beams was evaluated by COMSOL Multiphysics software. By changing beam shapes, microscopic objects can be trapped and rotated. This paper is in Japanese.

Determination of the Optical Properties of Individual Gold Nanorods through Numerical Modeling and Experiment

Y. Davletshin[1], J.C. Kumaradas[1]
[1]Ryerson University, Toronto, ON, Canada

The optical scattering and absorption of gold nanorods (GNRs) depends on its size, shape, and surroundings. This dependence is due to both intrinsic and extrinsic effects. A good understanding of this dependence is needed for applications of GNRs in photo-thermal therapy, optical and opto-acoustic imaging, biosensing, and other photonic areas. Extrinsic effects are caused by the production of ...

Full-Wave Analysis of Nanoscale Optical Trapping

E. Furlani, and A. Baev
The Institute for Lasers, Photonics and Biophotonics, University at Buffalo, Buffalo, NY, USA

Plasmonic-based optical trapping is in its infancy and growing rapidly. Research in this area will significantly advance fundamental understanding in fields such as nanophotonics and biophotonics. Novel plasmonic trapping structures and systems can be designed and optimized using the COMSOL RF solver.   We present a study of plasmonicbased optical trapping of neutral sub-wavelength ...

Plasmonics Based Keys for Image Encryption that Uses Exclusive OR Logic Operation - new

N. K. Nishchal[1], A. Fatima[1], I. Mehra[1], D. Kumar[1]
[1]Indian Institute of Technology Patna, Patna, Bihar, India

Optical encryption has become a significant research field due to its remarkable advantages [1-5]. The unique features of plasmonics have drawn researchers’ attention towards the role which it can play in information security [3 & 4]. The electric field is greatly enhanced when a metallic nanoparticle is illuminated by an appropriate electromagnetic field. The distribution and enhancement of ...

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 ...

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