Integrated Systems and Photonics

Modeling

Modelling is an important tool for design and optimisation. The first step when modelling is determining the dominant physical effects in the system under investigation. Then analytical or numerical methods are used to calculate the behaviour of the system. In so doing, the influence of design parameters on the function of the system is investigated.


For numerical calculation, we primarily use the finite element method (FEM) and the finite-difference time-domain (FDTD) method. FEM is particularly suitable for multiphysics modelling. We are able to use this method to solve, for example, coupled differential equation systems with mechanical, piezoelectric and magnetostrictive properties, in the area of magnetic field sensors. The FDTD method is particularly useful for issues related to nanostructured optical components. We also develop our own programmes for specific problems.
The illustrations show, as an example, results for the transmission spectrum of a nanostructured waveguide with two superimposed periods. All three numerical methods deliver the same result, and a fundamental correlation with the experiment is visible.

 

 

Figure 1:
Figure 1: Waveguide structure with two superimposed periods with superimposed network for calculation using the finite element method (FEM).
Figure 2:
Figure 2: Comparison of the results of different simulation methods as well as with the experiment for a nanostructured waveguide with two superimposed periods (RCWA: rigorous coupled-wave analysis; FDTD: finite-difference time-domain method).

Selected Publications

M. Paulsen, L. Neustock, S. Jahns, J. Adam, M. Gerken, "Simulation methods for multiperiodic and aperiodic nanostructured dielectric waveguides", Optical and Quantum Electronics, vol: 49:107 (2017).
Link: »https://doi.org/10.1007/s11082-017-0918-6

L. T. Neustock, S. Jahns, J. Adam & M. Gerken. "Optical waveguides with compound multiperiodic grating nanostructures for refractive index sensing", Journal of Sensors, 501, 6174527 (2016).
Link: »https://dx.doi.org/10.1155/2016/6174527

J. L. Gugat, M. Krantz, M. Gerken, "Two-Dimensional Versus Three-Dimensional Finite Element Method Simulations of Cantilever Magnetoelectric Sensors", Magnetics, IEEE Transactions on , vol. 49, iss 10, pp. 5287-5283 doi: 10.1109/TMAG.2013.2260346 (2013)
Link: »https://doi.org/10.1109/TMAG.2013.2260346