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 of a Diffraction Grating Coupled Waveguide Based Biosensor for Microfluidic Applications

Y. Wu [1], M. L. Adams [1],
[1] Auburn University, Auburn, AL, USA

Grating couplers are a common optical component for introducing light into chip-based photonic structures. They are used extensively for optical interconnects and optical device integration. A microfluidic diffraction grating coupled waveguide (MDGCW) biosensor applies a grating coupler for label-free detection of a biological analyte. A novel MDGCW is modeled and the results presented. The ...

Optimized Illumination Directions of Single-Photon Detectors Integrated with Different Plasmonic Structures

M. Csete[1], Á. Sipos[1], A. Szalai[1], G. Szabó[1]
[1]Department of Optics and Quantum Electronics, University of Szeged, Szeged, Hungary

The optimal orientations of different single-photon detector designs were determined by COMSOL software package. Absorption of niobium-nitride (NbN) stripes in two different (p=220 nm, 3p=660 nm) periodic patterns integrated with plasmonic elements was studied. In OC-SNSPDs consisting of ~quarter-photon-wavelength nano-cavity the optimum direction is perpendicular incidence onto NbN stripes in P ...

Simulation, Fabrication and Observation of Plasmonic Halos

F. Ye[1], M. Burns[1], J. Merlo[1], M. Naughton[1]
[1]Department of Physics, Boston College, Chestnut Hill, MA, USA

We present the simulation, observation and systematic study of a novel optical phenomenon, a “plasmonic halo”, wherein optically pumped surface plasmons on circular silver microcavities form confined drumhead modes that, under off-resonant conditions, transform to colorful far field radiation at their circumferential boundaries. We simulated the surface plasmon drumhead modes via COMSOL ...

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 ...

Coupling Picosecond Terahertz Pulses to a Scanning Tunneling Microscope

P. H. Nguyen [1], C. Rathje [2], G. J. Hornig [1], V. Jelic [1], C. Ropers [2], F. A. Hegmann [1],
[1] University of Alberta, Edmonton, AB, Canada
[2] 4th Physical Institute, University of Göttingen, Göttingen, Germany

Probing ultrafast processes over subpicosecond and picosecond time scales provides fundamental insight into the nature of materials. We have experimentally demonstrated terahertz (THz)-pulse-induced tunneling in a scanning tunneling microscope (THz-STM) to image surfaces with simultaneous nanometer spatial resolution and subpicosecond time resolution [1]. However, the exact mechanism by which ...

A Novel Wavelength Detection Method Based on Wavelength Absorption in Silicon

K. Zhang [1], Y. Audet [1],
[1] École Polytechnique de Montréal, Montréal, QC, Canada

A new filter-less method of detecting the spectrum based on wavelength absorption in silicon is proposed. Wavelength dependent absorption coefficient produces a unique excess carrier distribution. Thus the wavelength spectral information can be obtained by measuring the photon generated electron-hole pairs as a function of depth. A model built with the COMSOL Multiphysics® software along with ...

Finite Element Analysis of Integrated Circuit Interconnect Lines on Lossy Silicon Substrate

S. Musa[1], M. Sadiku[1], and A. Emam[2]

[1]Roy G. Perry College of Engineering, Prairie View A&M University, Prairie View, TX
[2]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 ...

Updated Results of Singlet Oxygen Modeling Incorporating Local Vascular Diffusion for PDT - new

R. Penjweini[1], M. M. Kim[1], T. C. Zhu[1]
[1]Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA

Introduction: Singlet oxygen (¹O₂) has a critical role in the cell-killing mechanism of photodynamic therapy (PDT). Therefore, in this study, the distance-dependent reacted ¹O₂ is numerically calculated using finite-element method (FEM). Herein, we use a model [Ref. 1] that has been previously developed to incorporate the diffusion equation for the light transport in tissue and the macroscopic ...

Time-Resolved Optical Tomography in Preclinical Studies: Propagation of Excitation and Fluorescence Photons.

F. Nouizi[1], R. Chabrier[1], M. Torregrossa[2], and P. Poulet[1]
[1]Laboratoire d’Imagerie et de Neurosciences Cognitives, Straßbourg, France
[2]Laboratoire des Sciences de l'Image, de l'Informatique et de la Télédétection, France

We present time-resolved methods that rely on near-infrared photons to image the optical properties and distribution of fluorescent probes in small laboratory animals. The coupled diffusion equations of excitation and fluorescence photons in highly scattering tissues were solved using the three-dimensional Finite Element Method (FEM) provided by COMSOL. The computed results allowed to yield ...

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 ...