Defence of doctoral thesis in the field of Micro- and nanosciences, M.Sc.(Tech.) Henrik Mäntynen
M.Sc.(Tech.) Henrik Mäntynen will defend the thesis "Nanophotonics with Group III-V Compound Semiconductor Nanowires" on 11 February 2022 at 12 in Aalto University School of Electrical Engineering, Department of Electronics and Nanoengineering.
Opponent: Prof. Bernd Witzigmann, Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany
Custos: Prof. Harri Lipsanen, Aalto University School of Electrical Engineering, Department of Electronics and Nanoengineering
Thesis available for public display at: https://aaltodoc.aalto.fi/doc_public/eonly/riiputus/
Doctoral theses in the School of Electrical Engineering: https://aaltodoc.aalto.fi/handle/123456789/53
With modern fabrication techniques, it is possible to controllably create structures for nanophotonics applications such that their optical properties depend not only on the material but also on light diffraction effects. Crystalline group III–V compound semiconductor nanowires typically have diameters smaller than the wavelength of near-infrared and visible light, and they present useful optical properties for nanophotonics applications as well as unique opportunities via bottom-up growth fabrication. For research and design of these nanophotonics applications, numerical optics modeling is an invaluable tool which helps to increase the understanding of the physical operation principles and to reduce costly and time-consuming prototyping. This thesis presents the results of several studies that aimed to advance the research fields of III–V nanowire nanophotonics applications and numerical optics modeling.
In the work, first, a review study was conducted on bottom-up-grown III–V nanowire single-photon sources with embedded quantum dot emitters. The results obtained from this study provide a better overview of these sources than before and help to direct future research efforts. Second, a numerical study was conducted on optical waveguide modes in vertical nanowire oligomers, and the suitability of such modes for lasing was considered based on their modal properties. The optical waveguide modes in nanowire oligomers provided a novel research topic, as previously reported studies had largely considered guided modes and laser applications for only single nanowires. Finally, efficient numerical optics modeling techniques were considered. A more widely applicable symmetry reduction method for finite element method models in linear optics scattering problems was presented and the issue of relative numerical performance and choosing between the Fourier modal method, finite element method, and finite-difference time-domain method in light absorption simulations was addressed. The results obtained from these studies will help to improve the efficiency of linear optics scattering problems simulations, which in turn leads to faster design processes with reduced costs and energy consumption.
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