C. Kraeh, and H. Hedler
Siemens AG, Munich
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 ...
S. Ni, C. Yang Koh, S. Kooi, and E. Thomas
Institute for Soldier Nanotechnologies
Dept. of Materials Science and Eng.
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 ...
K. Tarnowski, W. Salejda
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, N. Mirabolfathi, B. Sadoulet, K. M. Sundqvist
Department of Physics, University of California - Berkeley, Berkeley, CA, USA
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 ...
TM Wave Propagation in Optical Nanostructures with a Third-Order Nonlinear Response: Modeling and Validation with COMSOL
A. Kildishev, E. E. Narimanov
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 ...
T. Hutter, N. Bamiedakis, and S. Elliott
Department of Chemistry, University of Cambridge, UK
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 ...
S. Musa, M. Sadiku, and A. Emam
Roy G. Perry College of Engineering, Prairie View A&M University, Prairie View, TX
Information Systems Department, King Saud University, Riyadh, Saudi Arabia
The silicon substrate has a significant effect on the inductance parameter of a lossy interconnect line on an integrated circuit. It is essential to take this into account in determining the transmission line electrical parameters. In this paper, a new quasi-TEM capacitance and inductance analysis of multiconductor multilayer interconnects is successfully demonstrated using the finite element ...
P. Mikulski, K. Mcilhany, and R. Malek-Madani
United States Naval Academy
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 ...
FE Modeling of Surfaces with Realistic 3D Roughness: Roughness Effects in Optics of Plasmonic Nanoantennas
J. Borneman, A. Kildishev, K. Chen, and V. Drachev
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 ...
N. Katte, J. Haus, J.B. Serushema, and M. Scalora
University of Dayton, Dayton, OH, USA
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 ...