Mitarbeitende

Niklas Georg M.Sc.

Aufgabenbereich

Simulation hochfrequenter und optischer Komponenten mit Unsicherheiten

Kontakt

work +49 6151 16-24393

Work S2|17 33
Schloßgartenstr. 8
64289 Darmstadt

Numerical simulations are well established and play an important role in the design process of electromagnetic components. Thereby, the geometry of the devices and the material properties which are the input data of the numerical simulation, are generally assumed to be known exactly. However, this is not the case in practice, since the manufacturing process introduces (possibly small) variations which usually can only be described statistically. Additionally, there is often a lack of knowledge about the material data due to measurement errors. These uncertainties in the input data can then cause the real components to fail the design specifications. It also favors the choice of disproportionate safety factors. This is especially problematic because of the decreasing size of structures and increasing demands on the components, e.g. in nanotechnology.

Therefore, favored by the continuously increasing computing power, uncertainty quantification (UQ) is a topic of great interest. UQ aims for realistic predictions by describing input data as well as output data as random variables. The probability density function (PDF) of the inputs is then propagated to the outputs, i.e. the quantities of interest (QoIs). In many cases it can also be sufficient to compute a few statistical moments, e.g. mean and standard deviation of the QoI. This could be achieved by applying the well-known Monte Carlo (MC) simulation. However, MC simulation is too computationally expensive for many applications since it needs many (possibly millions) of simulation runs in order to obtain reliable results. In this research, spectral methods for efficient UQ of high-frequency and optical components are investigated. In particular, periodic metamaterials and plasmonic structures are considered which can be subject to relatively huge manufacturing imperfections.

Young Scientist Award und zweiter Platz beim Best Paper Award auf der URSI HKHB 2019 für den Beitrag 'Improved surrogate modeling for uncertainty quantification of an optical grating coupler'

2020

Ziegler, Anna ; Georg, Niklas ; Schöps, Sebastian (2020):
Automatic Mode Recognition for Superconducting Cavities using Shape Morphing and Eigenvalue Tracking.
In: Workshop on Advances in Electromagnetic Research – KWT 2020. URL: http://maxwell-in-motion.org. [Talk]

Georg, Niklas ; Römer, Ulrich ; Schuhmann, Rolf (2020):
Decoupled Uncertainty Propagation for Quasi-Periodic Optical Structures.
In: Workshop on Advances in Electromagnetic Research – KWT 2020. URL: http://maxwell-in-motion.org. [Talk]

Georg, Niklas ; Römer, Ulrich (2020):
Conformally Mapped Polynomial Chaos Expansions for Uncertain Dynamical Systems.
In: 21st IFAC World Congress 2020, Berlin. URL: https://www.ifac2020.org/. [Talk]

Georg, Niklas ; Lehmann, Christian ; Römer, Ulrich ; Schuhmann, Rolf (2020):
Multifidelity Uncertainty Quantification for Optical Structures.
In: 13th Conference on Scientific Computing in Electrical Engineering (SCEE 2020), Eindhoven. URL: https://www.scee-conferences.org/. [Talk]

Georg, Niklas ; Römer, Ulrich (2020):
Conformally Mapped Polynomial Chaos Expansions for Maxwell's Source Problem with Random Input Data.
In: International Journal of Numerical Modelling: Electronic Networks, Devices and Fields, pp. 1–15, ISSN: 0894-3370, DOI: 10.1002/jnm.2776, ARXIV: 2005.05152. [Article]

Georg, Niklas ; Loukrezis, Dimitrios ; Römer, Ulrich ; Schöps, Sebastian (2020):
Enhanced adaptive surrogate models with applications in uncertainty quantification for nanoplasmonics.
In: International Journal for Uncertainty Quantification, 10, (2), pp. 165–193, ISSN: 2152-5080, DOI: 10.1615/Int.J.UncertaintyQuantification.2020031727, ARXIV: 1807.07485. [Article]

Fuhrländer, Mona ; Georg, Niklas ; Römer, Ulrich ; Schöps, Sebastian (2020):
Yield Optimization Based on Adaptive Newton-Monte Carlo and Polynomial Surrogates.
In: International Journal for Uncertainty Quantification, 10, (4), pp. 351–373, ISSN: 2152-5080, DOI: 10.1615/Int.J.UncertaintyQuantification.2020033344, ARXIV: 1912.09908. [Article]

Corno, Jacopo ; Georg, Niklas ; Gorgi Zadeh, Shahnam ; Heller, Johann ; Gubarev, Vladimir ; Roggen, Toon ; Römer, Ulrich ; Schmidt, Christian ; Schöps, Sebastian ; Schultz, Julius ; Sulimov, Alexey ; van Rienen, Ursula (2020):
Uncertainty modeling and analysis of the European X-ray free electron laser cavities manufacturing process.
In: Nuclear Instruments & Methods in Physics Research Section A – Accelerators, Spectrometers, Detectors and Associated Equipment, 971, pp. 164135, ISSN: 0168-9002, DOI: 10.1016/j.nima.2020.164135. [Article]

2019

Schmitt, Nikolai ; Georg, Niklas ; Brière, Gauthier ; Loukrezis, Dimitrios ; Héron, Sébastien ; Lanteri, Stéphane ; Klitis, Charalambos ; Sorel, Marc ; Römer, Ulrich ; De Gersem, Herbert ; Vézian, Stéphane ; Genevet, Patrice (2019):
Optimization and uncertainty quantification of gradient index metasurfaces.
In: Optical Materials Express, 9, (2), pp. 892–910, DOI: 10.1364/OME.9.000892. [Article]

Georg, Niklas ; Römer, Ulrich (2019):
Improved surrogate modeling for uncertainty quantification of an optical grating coupler.
In: URSI Kleinheubacher Tagung (KHB 2019), Miltenberg. URL: https://www.kh2019.de. [Poster]

Georg, Niklas ; Römer, Ulrich (2019):
Improved surrogate modeling for uncertainty quantification of an optical grating coupler.
In: URSI Kleinheubacher Tagung (KHB 2019), Miltenberg. URL: https://www.kh2019.de. [Talk]

Georg, Niklas ; Römer, Ulrich ; Schöps, Sebastian (2019):
Surrogate Modeling for Optical Gratings based on Polynomial Approximations and Conformal Maps.
In: Workshop on Advances in Electromagnetic Research – KWT 2019, Rietzlern, Austria. URL: http://maxwell-in-motion.org. [Talk]

Georg, Niklas ; Loukrezis, Dimitrios ; Römer, Ulrich ; Schöps, Sebastian (2019):
Uncertainty quantification for optical metasurfaces.
In: UNCECOMP 2019. URL: https://2019.uncecomp.org/. [Talk]

Georg, Niklas ; Loukrezis, Dimitrios ; Römer, Ulrich ; Schöps, Sebastian (2019):
Uncertainty Quantification for an Optical Grating Coupler using Adaptive Polynomial Approximations and Conformal Maps.
In: Doktorandentage - Institut für Dynamik und Schwingungen, Technische Universität Braunschweig. [Talk]

Georg, Niklas ; Ackermann, Wolfgang ; Corno, Jacopo ; Schöps, Sebastian (2019):
Uncertainty quantification for Maxwell’s eigenproblem using isogeometric analysis and mode tracking.
In: Computer Methods in Applied Mechanics and Engineering, 350, pp. 228–244, ISSN: 0045-7825, DOI: 10.1016/j.cma.2019.03.002, ARXIV: 1802.02978. [Article]

Fuhrländer, Mona ; Georg, Niklas ; Schöps, Sebastian (2019):
Yield Estimation and Optimization of Electromagnetic Devices.
In: 9th International Congress on Industrial and Applied Mathematics (ICIAM 2019), Valencia, Spain. URL: https://iciam2019.org. [Talk]

2018

Georg, Niklas ; Loukrezis, Dimitrios ; Römer, Ulrich ; Schöps, Sebastian (2018):
Uncertainty Quantification for Optical Metasurfaces with Adjoint Error-Based Adaptive Collocation.
In: Workshop on UQ for acoustic simulations, Braunschweig. [Talk]

Georg, Niklas ; Corno, Jacopo ; De Gersem, Herbert ; Gorgi Zadeh, Shahnam ; Römer, Ulrich ; Schöps, Sebastian ; Sulimov, Alexey ; van Rienen, Ursula (2018):
Uncertainty quantification for the fundamental mode spectrum of the European XFEL Cavities.
In: 13th International Computational Accelerator Physics Conference (ICAP18), Florida, USA. URL: http://bt.pa.msu.edu/ICAP18. [Talk]

Georg, Niklas ; Loukrezis, Dimitrios ; Römer, Ulrich ; Schöps, Sebastian (2018):
Uncertainty Quantification for an Optical Grating Coupler with Adjoint-based Adaptive Collocation.
In: Workshop on Advances in Electromagnetic Research – KWT 2018, Rietzlern, Austria. URL: http://maxwell-in-motion.org. [Poster]

Georg, Niklas ; Loukrezis, Dimitrios ; Römer, Ulrich ; Schöps, Sebastian (2018):
Uncertainty Quantification for an Optical Grating Coupler with Adjoint Error-Based Adaptive Collocation.
In: WiRe seminar, Technische Universität Braunschweig, Braunschweig. [Talk]

Georg, Niklas (2018):
Numerical Simulation of an Optical Grating Coupler with Uncertainties using Adaptive Sparse-Grids based on Adjoint-Error Indicators. Technische Universität Darmstadt, Darmstadt. [Master's Thesis]

Georg, Niklas ; Römer, Ulrich ; Schöps, Sebastian ; Schuhmann, Rolf (2018):
Uncertainty Quantification for an Optical Grating Coupler using Adaptive Stochastic Collocation.
In: SIAM Conference on Uncertainty Quantification 2018, Garden Grove, USA. URL: https://www.siam.org/meetings/uq18. [Talk]

2017

Schöps, Sebastian ; Bontinck, Zeger ; Corno, Jacopo ; Georg, Niklas (2017):
Uncertainty Quantification in Electrical Engineering: Superconducting cavities, Magnets and Electrical Machines.
In: Kolloquium SFB 805, Darmstadt. URL: http://www.sfb805.tu-darmstadt.de/. [Talk]

Georg, Niklas ; Römer, Ulrich ; Schöps, Sebastian (2017):
Uncertainty Quantification for an Optical Grating Coupler using Generalized Polynomial Chaos.
In: Meeting of the Scientific Network UQ for Cavities 2017, Hamburg, Germany. [Talk]

Georg, Niklas ; Römer, Ulrich ; Schöps, Sebastian (2017):
Uncertainty Quantification for a Plasmon Waveguide using Stochastic Collocation.
In: Workshop on Advances in Electromagnetic Research – KWT 2017, Rietzlern, Austria. URL: http://maxwell-in-motion.org. [Talk]

Ackermann, Wolfgang ; Corno, Jacopo ; de Falco, Carlo ; Georg, Niklas ; Kellermann, Malena ; Krimm, Alexander ; Schöps, Sebastian (2017):
Eigenvalue Tracking for the Sensitivity Analysis of Resonant Modes in Superconducting Cavities.
In: URSI-B Workshop Felder und Wellen, Groß-Behnitz, Germany. [Talk]

2016

Georg, Niklas ; Römer, Ulrich ; Schuhmann, Rolf (2016):
Uncertainty Quantification for a Plasmonic Waveguide using Generalized Polynomial Chaos.
In: Workshop on Advances in Electromagnetic Research – KWT 2016, Rietzlern, Austria. URL: http://maxwell-in-motion.org. [Poster]

Ackermann, Wolfgang ; Corno, Jacopo ; de Falco, Carlo ; Georg, Niklas ; Kellermann, Malena ; Krimm, Alexander ; Schöps, Sebastian (2016):
Eigenvalue Tracking for the Sensitivity Analysis of Higher Order Modes.
In: ICFA Mini Workshop on High Order Modes in Superconducting Cavities (HOMSC 2016), Warnemünde. URL: http://indico.cern.ch/event/465683/. [Talk]

2015

Georg, Niklas (2015):
Shape derivatives for boundary value and interface problems in electro- and magnetostatics. Technische Universität Darmstadt, Darmstadt. [Bachelor's Thesis]