TY - CHAP A1 - Pomplun, Jan A1 - Zschiedrich, Lin A1 - Klose, Roland A1 - Schmidt, Frank A1 - Burger, Sven T1 - Finite Element Simulation of Radiation Losses in Photonic Crystal Fibers T2 - Nanophotonic Materials: Photonic Crystals, Plasmonics, and Metamaterials Y1 - 2008 U6 - https://doi.org/10.1002/9783527621880.ch17 SP - 313 EP - 331 PB - Wiley-VCH ER - TY - CHAP A1 - Wenzel, Hans A1 - Crump, Paul A1 - Ekhteraei, Hossein A1 - Schultz, Christoph M. A1 - Pomplun, Jan A1 - Burger, Sven A1 - Zschiedrich, Lin A1 - Schmidt, Frank A1 - Erbert, Götz T1 - Theoretical and experimental analysis of the lateral modes of high-power broad-area lasers T2 - Numerical Simulation of Optoelectronic Devices Y1 - 2011 U6 - https://doi.org/10.1109/NUSOD.2011.6041183 SP - 143 EP - 144 ER - TY - JOUR A1 - Sontheimer, Tobias A1 - Preidel, Veit A1 - Lockau, Daniel A1 - Back, Franziska A1 - Rudigier-Voigt, Eveline A1 - Löchel, Bernd A1 - Erko, Alexei A1 - Schmidt, Frank A1 - Schnegg, Alexander A1 - Lips, Klaus A1 - Becker, Christiane A1 - Rech, Bernd T1 - Correlation between structural and opto-electronic characteristics of crystalline Si microhole arrays for photonic light management JF - Journal of Applied Physics Y1 - 2013 U6 - https://doi.org/10.1063/1.4829008 VL - 114 IS - 17 SP - 173513 PB - AIP Publishing ER - TY - JOUR A1 - Lockau, Daniel A1 - Sontheimer, Tobias A1 - Preidel, Veit A1 - Ruske, Florian A1 - Hammerschmidt, Martin A1 - Becker, Christiane A1 - Schmidt, Frank A1 - Rech, Bernd T1 - Advanced microhole arrays for light trapping in thin film silicon solar cells JF - Solar Energy Materials and Solar Cells Y1 - 2014 U6 - https://doi.org/10.1016/j.solmat.2013.11.024 VL - 125 SP - 298 EP - 304 ER - TY - JOUR A1 - Kirner, Simon A1 - Hammerschmidt, Martin A1 - Schwanke, Christoph A1 - Lockau, Daniel A1 - Calnan, Sonya A1 - Frijnts, Tim A1 - Neubert, Sebastian A1 - Schöpke, Andreas A1 - Schmidt, Frank A1 - Zollondz, Jens-Hendrik A1 - Heidelberg, Andreas A1 - Stannowski, Bernd A1 - Rech, Bernd A1 - Schlatmann, Rutger T1 - Implications of TCO Topography on Intermediate Reflector Design for a-Si/μc-Si Tandem Solar Cells — Experiments and Rigorous Optical Simulations JF - IEEE Journal of Photovoltaics Y1 - 2014 U6 - https://doi.org/10.1109/JPHOTOV.2013.2279204 VL - 4 IS - 1 SP - 10 EP - 15 ER - TY - CHAP A1 - Hammerschmidt, Martin A1 - Pomplun, Jan A1 - Burger, Sven A1 - Schmidt, Frank T1 - Adaptive sampling strategies for effcient parameter scans in nano-photonic device simulations T2 - Proc. SPIE Y1 - 2014 U6 - https://doi.org/10.1117/12.2036363 VL - 8980 SP - 89801O PB - SPIE ER - TY - CHAP A1 - Hammerschmidt, Martin A1 - Lockau, Daniel A1 - Zschiedrich, Lin A1 - Schmidt, Frank T1 - Optical modelling of incoherent substrate light-trapping in silicon thin film multi-junction solar cells with finite elements and domain decomposition T2 - Proc. SPIE: Physics and Simulation of Optoelectronic Devices XXII Y1 - 2014 U6 - https://doi.org/10.1117/12.2036346 VL - 8980 SP - 898007 PB - SPIE ER - TY - CHAP A1 - Jäger, Klaus A1 - Barth, Carlo A1 - Hammerschmidt, Martin A1 - Herrmann, Sven A1 - Burger, Sven A1 - Schmidt, Frank A1 - Becker, Christiane ED - European Society for Quantum Solar Energy Conversion, T1 - Sinusoidal Nanotextures for Enhanced Light Management in Thin-Film Solar Cells T2 - 28th Workshop on Quantum Solar Energy Conversion - (QUANTSOL) Y1 - 2016 ER - TY - JOUR A1 - Jäger, Klaus A1 - Köppel, Grit A1 - Barth, Carlo A1 - Hammerschmidt, Martin A1 - Herrmann, Sven A1 - Burger, Sven A1 - Schmidt, Frank A1 - Becker, Christiane T1 - Sinusoidal gratings for optimized light management in c-Si thin-film solar cells JF - Proc. SPIE Y1 - 2016 U6 - https://doi.org/10.1117/12.2225459 VL - 9898 SP - 989808 ER - TY - CHAP A1 - Kantner, Markus A1 - Höhne, Theresa A1 - Koprucki, Thomas A1 - Burger, Sven A1 - Wünsche, Hans-Jürgen A1 - Schmidt, Frank A1 - Mielke, Alexander A1 - Bandelow, Uwe ED - Kneissl, Michael ED - Knorr, Andreas ED - Reitzenstein, Stephan ED - Hoffmann, Axel T1 - Multi-dimensional modeling and simulation of semiconductor nanophotonic devices T2 - Semiconductor Nanophotonics Y1 - 2020 U6 - https://doi.org/10.1007/978-3-030-35656-9_7 VL - 194 SP - 241 EP - 283 PB - Springer CY - Cham ER - TY - CHAP A1 - Hiremath, Kirankumar A1 - Zschiedrich, Lin A1 - Burger, Sven A1 - Schmidt, Frank T1 - Finite elements based numerical solution of nonlocal hydrodynamic Drude model of nano-plasmonic scatterers T2 - 12th International Conference on Fiber Optics and Photonics Y1 - 2014 U6 - https://doi.org/10.1364/PHOTONICS.2014.M3D.4 SP - M3D.4 ER - TY - GEN A1 - Deuflhard, Peter A1 - Friese, Tilmann A1 - Schmidt, Frank A1 - März, Reinhard A1 - Nolting, Hans-Peter T1 - Effiziente Eigenmodenberechnung für den Entwurf integriert-optischer Chips N2 - {\bf Efficient eigenmode computation for the design of integrated optical chips.}The paper deals with adaptive multigrid methods for 2D Helmholtz eigenvalue problems arising in the design of integrated optical chips. Typical features of the technological problem are its geometric complexity, its multiscale structure, the possible occurrence of eigenvalue clusters, and the necessity of quite stringent required relative error tolerances. For reasons of sheer computational complexity, multigrid methods must be used to solve the discretized eigenvalue problems and adaptive grids must be automatically constructed to avoid an undesirable blow-up of the required number of nodes for these accuracies. In view of the problem specifications, an adaptive multigrid method based on Rayleigh quotient minimization, simultaneous eigenspace iteration, and conjugate gradient method as smoother is carefully selected. Its performance in the numerical simulation of a component of a rather recent optical chip (heterodyne receiver of HHI) is documented. T3 - ZIB-Report - SC-96-02 Y1 - 1996 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-2131 ER - TY - GEN A1 - Schmidt, Frank A1 - Yevick, David T1 - Discrete Transparent Boundary Conditions for Schrödinger-Type Equations N2 - We present a general technique for constructing nonlocal transparent boundary conditions for one-dimensional Schrödinger-type equations. Our method supplies boundary conditions for the $\theta$-family of implicit one-step discretizations of Schrödinger's equation in time. The use of Mikusi\'nski's operator approach in time avoids direct and inverse transforms between time and frequency domains and thus implements the boundary conditions in a direct manner. T3 - ZIB-Report - SC-96-17 Y1 - 1996 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-2289 ER - TY - GEN A1 - Schmidt, Frank A1 - März, Reinhard T1 - On the Reference Wave Vector pf Paraxial Helmholtz Equations N2 - The reference wave vector of the paraxial Helmholtz equation is determined using various strategies which result all in similar expressions. The effort for its evaluation is so small that the reference wave vector can be adapted for each propagation step of an arbitrary BPM-algorithm. T3 - ZIB-Report - SC-94-38 Y1 - 1995 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-1660 ER - TY - GEN A1 - Deuflhard, Peter A1 - Schmidt, Frank T1 - Discrete Transparent Boundary Conditions for the Numerical Solution of Fresnel's Equation. N2 - The paper presents a construction scheme of deriving transparent , i. e. reflection-free, boundary conditions for the numerical solution of Fresnel's equation (being formally equivalent to Schrödinger's equation). These boundary conditions appear to be of a nonlocal Cauchy type. As it turns out, each kind of linear implicit discretization induces its own discrete transparent boundary conditions. T3 - ZIB-Report - SC-93-24 Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-1205 ER - TY - GEN A1 - Schmidt, Frank T1 - An Adaptive Approach to the Numerical Solution of Fresnel's Wave Equation. N2 - An adaptive approach to the numerical solution of the wave propagation in integrated optics devices with 1D cross sections is described. First, Fresnel's approximation of the exact wave equation resulting from Maxwell's equations is considered. A criterion to estimate the validity of this approximation is derived. Fresnel's wave equation being formally equivalent to Schroedinger's equation uniquely defines an initial-boundary-value problem, which is solved numerically by a stepwise calculation of the propagating field. Discretization in longitudinal direction first with stepsize control leads to a stationary subproblem for the transversal field distribution, which is then handled by an adaptive finite element method. Thus full adaptivity of the algorithm is realized. The numerical examples are concentrated on taper structures playing an essential role in integrated optics devices for telecommunication systems. T3 - ZIB-Report - SC-91-12 Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-628 ER - TY - GEN A1 - Schmidt, Frank T1 - Computation of Discrete Transparent Boundary Conditions for the 2D Helmholtz Equation N2 - We present a family of nonlocal transparent boundary conditions for the 2D Helmholtz equation. The whole domain, on which the Helmholtz equation is defined, is decomposed into an interior and an exterior domain. The corresponding interior Helmholtz problem is formulated as a variational problem in standard manner, representing a boundary value problem, whereas the exterior problem is posed as an initial value problem in the radial variable. This problem is then solved approximately by means of the Laplace transformation. The derived boundary conditions are asymptotically correct, model inhomogeneous exterior domains and are simple to implement. T3 - ZIB-Report - SC-97-64 Y1 - 1997 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-3330 ER - TY - GEN A1 - Schmidt, Frank T1 - An Alternative Derivation of the Exact DtN-Map on a Circle N2 - The paper supplies an alternative derivation of the exact boundary conditions needed for the solution of time-harmonic acoustic scattering problems modeled by the Helmholtz equation. The main idea is to consider the exterior domain problem as an initial value problem with initial data given on the boundary of a disc or sphere. The solution of the exterior domain problem is obtained via Laplace transformation techniques, where the asymptotic Sommerfeld radiation condition is reformulated accordingly. T3 - ZIB-Report - SC-98-32 KW - Helmholtz equation KW - Dirichlet-to-Neumann map KW - Sommerfeld radiation condition Y1 - 1998 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-3752 ER - TY - BOOK A1 - Abbink, Erwin A1 - Bärmann, Andreas A1 - Bešinovic, Nikola A1 - Bohlin, Markus A1 - Cacchiani, Valentina A1 - Caimi, Gabrio A1 - de Fabris, Stefano A1 - Dollevoet, Twan A1 - Fischer, Frank A1 - Fügenschuh, Armin A1 - Galli, Laura A1 - Goverde, Rob M.P. A1 - Hansmann, Ronny A1 - Homfeld, Henning A1 - Huisman, Dennis A1 - Johann, Marc A1 - Klug, Torsten A1 - Törnquist Krasemann, Johanna A1 - Kroon, Leo A1 - Lamorgese, Leonardo A1 - Liers, Frauke A1 - Mannino, Carlo A1 - Medeossi, Giorgio A1 - Pacciarelli, Dario A1 - Reuther, Markus A1 - Schlechte, Thomas A1 - Schmidt, Marie A1 - Schöbel, Anita A1 - Schülldorf, Hanno A1 - Stieber, Anke A1 - Stiller, Sebastian A1 - Toth, Paolo A1 - Zimmermann, Uwe ED - Borndörfer, Ralf ED - Klug, Torsten ED - Lamorgese, Leonardo ED - Mannino, Carlo ED - Reuther, Markus ED - Schlechte, Thomas T1 - Handbook of Optimization in the Railway Industry N2 - This book promotes the use of mathematical optimization and operations research methods in rail transportation. The editors assembled thirteen contributions from leading scholars to present a unified voice, standardize terminology, and assess the state-of-the-art. There are three main clusters of articles, corresponding to the classical stages of the planning process: strategic, tactical, and operational. These three clusters are further subdivided into five parts which correspond to the main phases of the railway network planning process: network assessment, capacity planning, timetabling, resource planning, and operational planning. Individual chapters cover: Simulation Capacity Assessment Network Design Train Routing Robust Timetabling Event Scheduling Track Allocation Blocking Shunting Rolling Stock Crew Scheduling Dispatching Delay Propagation Y1 - 2018 SN - 978-3-319-72152-1 U6 - https://doi.org/10.1007/978-3-319-72153-8 VL - 268 PB - Springer Verlag ER - TY - THES A1 - Schmidt, Frank T1 - A New Approach to Coupled Interior-Exterior Helmholtz-Type Problems: Theory and Algorithms N2 - The work presents a new approach to the numerical solution of time-harmonic and time-dependent scattering problems. We replace Sommerfeld's radiation condition valid for the Helmholtz equation by a more general concept called pole condition. The pole condition is based on the Laplace transform of the exterior solution and allows a characterization of outgoing waves. Both new insight into the analysis of scattering problems as well as new numerical algorithms are obtained. T3 - ZIB-Report - 02-45 KW - Pole condition KW - Helmholtz equation KW - Wide angle one-way equation KW - Schroedinger equation KW - Transparent boundary conditions KW - Unbounded domains KW - Fini Y1 - 2002 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-7128 ER - TY - GEN A1 - Cordes, Frank A1 - Weber, Marcus A1 - Schmidt-Ehrenberg, Johannes T1 - Metastable Conformations via successive Perron-Cluster Cluster Analysis of dihedrals N2 - Decomposition of the high dimensional conformational space of bio-molecules into metastable subsets is used for data reduction of long molecular trajectories in order to facilitate chemical analysis and to improve convergence of simulations within these subsets. The metastability is identified by the Perron-cluster cluster analysis of a Markov process that generates the thermodynamic distribution. A necessary prerequisite of this analysis is the discretization of the conformational space. A combinatorial approach via discretization of each degree of freedom will end in the so called ''curse of dimension''. In the following paper we analyze Hybrid Monte Carlo simulations of small, drug-like biomolecules and focus on the dihedral degrees of freedom as indicators of conformational changes. To avoid the ''curse of dimension'', the projection of the underlying Markov operator on each dihedral is analyzed according to its metastability. In each decomposition step of a recursive procedure, those significant dihedrals, which indicate high metastability, are used for further decomposition. The procedure is introduced as part of a hierarchical protocol of simulations at different temperatures. The convergence of simulations within metastable subsets is used as an ''a posteriori'' criterion for a successful identification of metastability. All results are presented with the visualization program AmiraMol. T3 - ZIB-Report - 02-40 KW - metastability KW - Perron-Cluster Cluster Analysis KW - curse of dimension KW - Hybrid Monte Carlo KW - significant dihedrals Y1 - 2002 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-7074 ER - TY - GEN A1 - Zschiedrich, Lin A1 - Klose, Roland A1 - Schädle, Achim A1 - Schmidt, Frank T1 - A new Finite Element realization of the Perfectly Matched Layer Method for Helmholtz scattering problems on polygonal domains in 2D N2 - In this paper we propose a new finite element realization of the Perfectly Matched Layer method (PML-method). Our approach allows to deal with arbitrary shaped polygonal domains and with certain types of inhomogeneous exterior domains. Among the covered inhomogeneities are open waveguide structures playing an essential role in integrated optics. We give a detailed insight to implementation aspects. Numerical examples show exponential convergence behavior to the exact solution with the thickness of the PML sponge layer. T3 - ZIB-Report - 03-44 KW - transparent boundary conditions KW - perfectly matched layer KW - pole condition Y1 - 2003 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-7662 ER - TY - GEN A1 - May, Andreas A1 - Eisenhardt, Steffen A1 - Schmidt-Ehrenberg, Johannes A1 - Cordes, Frank T1 - Rigid body docking for Virtual Screening N2 - A recently developed algorithm allows Rigid Body Docking of ligands to proteins, regardless of the accessibility and location of the binding site. The Docking procedure is divided into three subsequent optimization phases, two of which utilize rigid body dynamics. The last one is applied with the ligand already positioned inside the binding pocket and accounts for full flexibility. Initially, a combination of geometrical and force-field based methods is used as a Coarse Docking strategy, considering only Lennard-Jones interactions between the target and pharmaceutically relevant atoms or functional groups. The protein is subjected to a Hot Spot Analysis, which reveals points of high affinity in the protein environment towards these groups. The hot spots are distributed into different subsets according to their group affiliation. The ligand is described as a complementary point set, consisting of the same subsets. Both sets are matched in $\mathrm{I\!R}^{3}$, by superimposing members of the same subsets. In the first instance, steric inhibition is nearly neglected, preventing the system's trajectory from trapping in local minima and thus from finding false positive solutions. Hence the exact location of the binding site can be determined fast and reliably without any additional information. Subsequently, errors resulting from approximations are minimized via finetuning, this time considering both Lennard-Jones and Coulomb forces. Finally, the potential energy of the whole complex is minimized. In a first evaluation, results are rated by a reduced scoring function considering only noncovalent interaction energies. Exemplary Screening results will be given for specific ligands. T3 - ZIB-Report - 03-47 KW - docking KW - point matching KW - identification of active sites Y1 - 2003 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-7690 ER - TY - GEN A1 - Yevick, David A1 - Friese, Tilmann A1 - Schmidt, Frank T1 - A Comparison of Transparent Boundary Conditions for the Fresnel Equation N2 - We establish the relationship between the transparent boundary condition (BPP) of Baskakov and Popov [Wave Motion 14 (1991) 121-128] and Pakpadakis et. al. [J. Acoust. Soc. Am. 92 (1992) 2030-2038] and a second boundary condition (SDY) introduced by Schmidt and Deuflhard [Comp. Math. Appl. 29 (1995) 53-76] and Schmidt and Yevick [J. Compu. Phys. 134 (1997) 96-107], that is explicitly tailored to the form of the underlying numerical propagation scheme. Our analysis demonstrates that if the domain is first discretized in the propagation direction, the SDY expression can be obtained by applying the exact sequence of steps used to derive the BPP procedure. The BPP method is thus an approximate realization of the computationally far simpler and unconditionally stable SDY boundary condition. T3 - ZIB-Report - 00-05 KW - Fresnel equation KW - transparent boundary condition Y1 - 2000 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-5738 ER - TY - GEN A1 - Schmidt, Frank T1 - Discrete Nonreflecting Boundary Conditions for the Helmholtz Equation N2 - We derive exact discrete nonreflecting boundary conditions for time-harmonic scattering problems modeled by the Helmholtz equation. The main idea is to consider the exterior problem as an initial value problem with initial data given on the boundary of the computational domain. The solution of the exterior problem is obtained via Laplace transformation techniques which supply the boundary conditions in terms of discrete Dirichlet-to-Neumann operators. T3 - ZIB-Report - 00-06 KW - Helmholtz equation KW - transparent boundary consitions KW - finite element method Y1 - 2000 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-5744 ER -