Lars Thorben is a PhD student in Electrical Engineering. In his research, he uses numerical methods to teach computers how to optimize physical devices. Here, he focuses on ion optical devices. The unintuitive shapes that his algorithms design can explore the full range of additive manufacturing of metallic devices. His past work includes the optimization of photonic crystal structures and virtual instrumentation for online education. Lars is an Accel Innovation Scholar at the Stanford Technology Ventures Program. Moreover, he was a Creativity in Research scholar, a program that he is now co-teaching. He is supported by the ERP-Program from the German Federal Ministry of Economics and Energy.
In his personal life, Lars is interested in the societal impact of emerging technologies. Moreover, he likes to stay fit and active by learning how to surf, doing heated Pilates workouts and going to the gym.
Current Research and Scholarly Interests
Lars's research interest lies at the intersection of optimization, applied physics and numerical methods. He is interested in understanding how we can use modern numerical methods and optimization techniques to improve physical devices in photon and charged particle optics. Hereby, the shape and topology of a device oftentimes plays a crucial role in its behavior. Lars is building computational models, including the application of adjoint design sensitivity analysis, to improve device shapes.
Currently, he is working on electron lensing devices. Other application of such computational tools range from optical tweezers and particle transport, near-field scanning microscopy and optical data storage to X-Ray systems.
While working on his research, Lars also encountered the limitations of todays tools of assisting research publications and outreach. Thus, he worked on the iLabs platform for research outreach and online education. This platform combines an interactive and scalable display of research data with social functionalities.
Inverse Design Tool for Ion Optical Devices using the Adjoint Variable Method.
2019; 9 (1): 11031
We present a computer-aided design tool for ion optical devices using the adjoint variable method. Numerical methods have been essential for the development of ion optical devices such as electron microscopes and mass spectrometers. Yet, the detailed computational analysis and optimization of ion optical devices is still onerous, since the governing equations of charged particle optics cannot be solved in closed form. Here, we show how to employ the adjoint variable method on the finite-element method and Störmer-Verlet method for electrostatic charged particle devices. This method allows for a full sensitivity analysis of ion optical devices, providing a quantitative measure of the effects of design parameters to device performance, at near constant computational cost with respect to the number of parameters. To demonstrate this, we perform such a sensitivity analysis for different freeform N-element Einzel lens systems including designs with over 13,000 parameters. We further show the optimization of the spot size of such lenses using a gradient-based method in combination with the adjoint variable method. The computational efficiency of the method facilitates the optimization of shapes and applied voltages of all surfaces of the device.
View details for DOI 10.1038/s41598-019-47408-w
View details for PubMedID 31363126
Remote Experimentation with Massively Scalable Online Laboratories
Online Engineering & Internet of Things
View details for DOI 10.1007/978-3-319-64352-6_24
Immersive Peer Education: Virtual Interactive Scalable Online Notebooks for Science (VISONS)
IEEE. 2018: 805–14
View details for Web of Science ID 000434866100116
Learning from the Unexpected: Statistics and Uncertainty in Massively Scalable Online Laboratories (MSOL)
IEEE. 2018: 815–24
View details for Web of Science ID 000434866100117
- Platform technology for mobile, label-free protein detection TM-TECHNISCHES MESSEN 2017; 84 (6): 426–35
- Simulation methods for multiperiodic and aperiodic nanostructured dielectric waveguides OPTICAL AND QUANTUM ELECTRONICS 2017; 49 (3)
Simulation methods for multiperiodic and aperiodic nanostructured dielectric waveguides.
Optical and quantum electronics
2017; 49 (3): 107
Nanostructured dielectric waveguides are of high interest for biosensing applications, light emitting devices as well as solar cells. Multiperiodic and aperiodic nanostructures allow for custom-designed spectral properties as well as near-field characteristics with localized modes. Here, a comparison of experimental results and simulation results obtained with three different simulation methods is presented. We fabricated and characterized multiperiodic nanostructured dielectric waveguides with two and three compound periods as well as deterministic aperiodic nanostructured waveguides based on Rudin-Shapiro, Fibonacci, and Thue-Morse binary sequences. The near-field and far-field properties are computed employing the finite-element method (FEM), the finite-difference time-domain (FDTD) method as well as a rigorous coupled wave algorithm (RCWA). The results show that all three methods are suitable for the simulation of the above mentioned structures. Only small computational differences are obtained in the near fields and transmission characteristics. For the compound multiperiodic structures the simulations correctly predict the general shape of the experimental transmission spectra with number and magnitude of transmission dips. For the aperiodic nanostructures the agreement between simulations and measurements decreases, which we attribute to imperfect fabrication at smaller feature sizes.
View details for DOI 10.1007/s11082-017-0918-6
View details for PubMedID 32214612
View details for PubMedCentralID PMC7062652
- Adjoint method for estimating Jiles-Atherton hysteresis model parameters JOURNAL OF APPLIED PHYSICS 2016; 120 (9)
Simulation of photonic waveguides with deterministic aperiodic nanostructures for biosensing
View details for DOI 10.1109/ICEAA.2016.7731570
- Properties of Deterministic Aperiodic Photonic Nanostructures for Biosensors Conference on Photonic and Electromagnetic Crystal Structures 2016
Optical Waveguides with Compound Multiperiodic Grating Nanostructures for Refractive Index Sensing
Journal of Sensors
View details for DOI 10.1155/2016/6174527
Wavelength dependency of outcoupling peak intensities for emission layers with multi-periodic photonic crystals.
Transparent Optical Networks (ICTON), 2014 16th International Conference on
View details for DOI 10.1109/ICTON.2014.6876593
- Emission tailoring for organic emitter layers with compound binary gratings MRS Spring Meeting 2014
- Calculation of leaky-wave radiation from compound binary grating waveguides XXIth International Workshop on Optical Wave & Waveguide Theory and Numerical Modelling 2013