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Aqui você encontrará apresentações realizadas nas Conferências de Usuários COMSOL de todo o mundo. As apresentações englobam pesquisas e produtos inovadores feitas por engenheiros e cientistas usando o COMSOL Multiphysics. Os tópicos abramgem uma grande gama de indústrias e aplicações, como elétrica, mecânica, escoamento e química. Use a função de busca "Quick Search" para encontrar apresentações na sua área de interesse.

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 ...

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 ...

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 ...

Purcell Effect via Numerical Simulation - new

I. Zabkov [1], V. Klimov[1], A. Pavlov[1], D. Guzatov[2]
[1]All-Russia Research Institute of Automatics (VNIIA), Moscow, Russia
[2]Yanka Kupala State University of Grodno, Grodno, Belarus

As it is known nano-sized emitters (such as atoms, quantum dots and point defects in diamonds) interaction with nano-environment leads to drastic changes of their decay rate and therefore lifetime (Purcell effect). To calculate the influence in general one needs to solve equations of quantum electrodynamics. However in weak interaction limit these emitters can be considered as point electric ...

Drift-Diffusion and Ballistic Transport Modeling in III-Nitride Multiple-QW Light Emitting Structures

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

COMSOL-based modeling software developed at Ostendo Technologies allows detailed simulation of semiconductor lasers and light-emitting diodes. In this work, we study the inhomogeneity of the carrier injection into optically active quantum wells of polar and nonpolar III-nitride light emitters. Despite the absence of polarization-induced potential barriers, the nonpolar multiple-quantum well ...

Electromagnetic Analysis of an Optical Measuring Device Installed in a Transmission Line - new

C. Soares[1], N. Padoin[1], A. C. Zimmermann[1], G. Cunha[2], P. B. Uliana[2], M. Wendhausen[2]
[1]Federal University of Santa Catarina, Florianópolis, SC, Brazil
[2]PowerOpticks Technology Ltda, Florianópolis, SC, Brazil

In this study, COMSOL Multiphysics® software was applied to the investigation of the electromagnetic behavior of an optical crystal submitted to the magnetic field generated by electric current in a near positioned metallic conductor. Moreover, the influence of a ferromagnetic apparatus (magnetic concentrator) on the magnetic field acting upon the crystal was investigated. Three cases were ...

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 ...

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 ...

Near-fields in Arrays of Triangular Particles: Coupling Effects and Field Enhancements

M. Goncalves[1], T. Makaryan[2], G. Papageorgiou[3], U. Herr[3], and O. Marti[1]
[1]Ulm University - Inst. of Experimental Physics, Ulm, Germany
[2]Yerevan State University, Yerevan, Armenia
[3]Ulm University - Institute of Micro and Nanomaterials, Ulm, Germany

Surface enhanced Raman scattering (SERS) investigations of silver and gold triangular nanoparticles reveal strong field enhancements at the corners of the particles. Though the measurements were done at wavelengths far from the surface-plasmon resonance of the particles, large field enhancements can be generated by near-field coupling between the triangular particles and smaller metal ...

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 ...