C. Del Vecchio, G. Agapito, G. Tomassi, and E. De Santis
National Institute for Astrophysics, Arcetri Astrophysical Observatory, Firenze, Italy
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 ...
A. Alabastri, R. Krahne, A. Giugni, G. Das, R. P. Zaccaria, M. Zanella, I. Franchini, and E. di Fabrizio
Italian Institute of Technology (IIT)
We studied the optical phonon excitations (LO) of ordered arrays of dot/ rod core-shell CdSe/ CdS nanorods by Raman spectroscopy. Upon deposition on planar substrates the nanorods formed super-lattice structures via side-by side assembly into tracks over some microns of length. COMSOL Multiphysics software has been used to calculate the magnitude of the electric field generated by the ...
Designers of electro-optic modulators and related devices often use separate tools to study the optical and electrical portions of the device. The flexibility of COMSOL Multiphysics makes it possible to construct unified models of EO phenomena including realistic waveguide profiles and anisotropic material properties. We demonstrate the use of the RF Module to compute both RF and optical ...
Complex K-Bands Calculation for Plasmonic Crystal Slabs by Means of Weak Formulation of Helmholtz's Eigenvalue Equation
G. Parisi, P. Zilio, F. Romanato
University of Padova, Padova, Italy
We present a Finite Element Method (FEM) to calculate the complex valued k(?) dispersion curves of a photonic crystal slab in presence of both dispersive and lossy materials. In particular the method can be exploited to study plasmonic crystal slabs. We adopt Perfectly Matched Layers (PMLs) in order to truncate the open boundaries of the model, including their related anisotropic permittivity ...
Optimized Illumination Directions of Single-Photon Detectors Integrated with Different Plasmonic Structures
M. Csete, Á. Sipos, A. Szalai, G. Szabó
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 ...
P. Gagnon, H. Manouzi, M. El Amraoui, Y. Messaddeq
Laval University, Quebec City, QC, Canada
An important step in designing a microstructured optical fiber is the computation and management of its dispersion curve. It is well-known that computing chromatic dispersion can be done analytically for certain geometries (e.g. step-index fibers), but no such analytical methods is known in the realm of microstructured optical fibers. Figure 1, Figure 2, and Figure 3 illustrate cross-sections of ...
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 ...
H. Karakuzu, M. Dubov, S. Boscolo
 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 ...
A. Pors, O. Albrektsen, S.I. Bozhevolnyi, and M. Willatzen
Mads Clausen Institute, University of Southern Denmark, Sønderborg, Denmark
Institute of Sensors, Signals and Electrotechnics, University of Southern Denmark, Odense, Denmark
The use of plasmonic effects to dramatically enhance the electromagnetic field near the surface of a metallic nanostructured surface has grown into a large research area in the effort to take advantage of the surface enhanced field. In this paper the electromagnetic field near a nano-sized truncated spherical cavity embedded in a gold substrate is investigated and modeled in 3D with COMSOL ...
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 ...