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.

Vertically Emitting Microdisk Lasers

L. Mahler, A. Tredicucci, and F. Beltram
NEST-INFM and Scuola Normale Superiore, Pisa, Italy

We describe the modeling of microdisk lasers displaying vertical emission. The devices are THz quantum cascade lasers with metallic gratings fabricated along the circumference.  The emission properties of the fabricated devices are well explained by the model, good mode control is obtained, and the collected power from a patterned device is increased 50 times with respect to unpatterned ...

Analysis of a Plasma-Mediated Photoacoustic Response From Plasmonic Nanoparticles in Ultrashort Regime

A. Hatef [1], B. Darvish [1], A. Dagallier [2], C. Boutopoulos [2], M. Meunier [2],
[1] Nipissing University, North Bay, ON, Canada
[2] École Polytechnique de Montréal, Montréal, QC, Canada

Over the last decade, plasmonic nanoparticles (PNPs) have received growing interest as exogenous contrast agents in the thermal expansion based photoacoustic (PA) imaging technique in biomedical applications [1]. Such functionality is due to the localized surface plasmon resonance (LSPR) created by the light-induced coherent oscillation of the conduction electrons in the PNPs. In the near-field ...

Fruit Optical Properties Assessment by Means of Spatially Resolved Spectroscopy

E. Madieta[1], V. Piron[2], A. Flament[1], J.P. L’Huillier[2], and E. Mehinagic[1]
[1]PRES L’UNAM, ESA, Grappe, Angers, France
[2]ENSAM Paristech, Angers, France

Since the invention of laser sources, understanding the interaction between the laser and biological tissues is a subject of great importance because of their medical applications in particular for diagnostic purposes. They recently found a growing interest in the sector of the arboriculture to check the fruits quality in a non-destructive way. In this work, we study the interaction between the ...

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 ...

Simulação de Fibras Retorcidas para a Geração de Modos com Momento Angular Orbital - new

F. Beltrán-Mejía[1, 2], C. M. B. Cordeiro[1]
[1]Universidade Estadual de Campinas - UNICAMP, SP, Brasil
[2]Atualmente no Instituto Nacional de Telecomunicações (INATEL), Santa Rita do Sapucaí, MG, Brasil

Uma fibra óptica retorcida pode se converter em uma estrutura longitudinalmente invariante através de uma transformação de coordenadas. O anterior permite fazer um analise de modos transversais da fibra, servindo para estudar a geração de modos com momento angular orbital (OAM). Atualmente, os modos OAM se encontram em diversas aplicações como na microscopia e nas telecomunicações entre ...

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 ...

Modeling of an Optical Black Hole with True Gaussian Beam Incidence

X. Ni[1], A. Kildishev[1], E. Narimanov[1], and L. Prokopeva[2]
[1]Purdue University, West Lafayette, IN, USA
[2]Russian Academy of Sciences, Novosibirsk, Russia

We model an ideal optical black hole device in COMSOL Multiphysics as an electromagnetic scattering problem. The device is illuminated with a Gaussian beam which is focused at a fixed position in horizontal direction (x0) and different positions in vertical direction (y0). The device is modeled as a cylindrical system with a gradient-index shell and absorbing core. Using the classical paraxial ...

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 ...

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 ...

COMSOL Multiphysics Super Resolution Analysis of a Spherical Geodesic Waveguide Suitable for Manufacturing

H. Ahmadpanahi[1], D. Grabovi?ki?[1], J.C. González[1], P. Benítez[1], J.C. Miñano[1]
[1]Cedint Universidad Politécnica de Madrid, Madrid, Spain

Recently it has been proved theoretically (Miñano et al, 2011) that the super-resolution up to ? /500 can be achieved using an ideal metallic Spherical Geodesic Waveguide (SGW). This SGW is as a theoretical design, in which the conductive walls are considered to be lossless conductors with zero thickness. In this paper, we study some key parameters that might influence the super resolution ...