Remanent switching of Bloch-polaritons

• Applicant: Dr. Chris Sturm
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2018 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 390089887

• Final Report Year: 2024

Final Report Abstract

Within this project we developed photonic structure which exhibit surface modes and are coupled to the excitonic resonance of ZnO, forming long range propagating surface exciton polaritons (Bloch surface polaritons). The strong coupling of the Bloch surface and the exciton was observable up to T = 430 K and a coupling strength of up to 100 meV at room temperature was determined. This coupling strength is, slightly larger than those observed for ZnO based microcavities with a similar cavity thickness. The increase can be attributed to the enhancement of the electric field distribution in the ZnO layer compared to the microcavities. In order to investigate the propagation properties of the Bloch surface polaritons, we developed strategy for a local pattering of the structures with gratings in order to excite these polaritons resonantly, and to investigate there emission locally. The optical properties of the gratings were investigated using spatially resolved reflectometry and ellipsometry. Non-idealities of the setup, such as the finite bandwidth of the monochromator, was taken into account. This allowed us to determine the geometric parameters of the gratings using ellipsometry and reflectance measurements. In the case of Bloch surface polaritons, we observed propagation lengths of up to 40 µm for the samples produced in the vicinity of the exciton resonance.

Publications

• Strong coupling of Bloch Surface Waves and excitons in ZnO up to 430 K, DPG Spring Meeting, online, 2021 (Poster).
  S. Henn, M. Grundmann & C. Sturm
  
• Strong coupling of Bloch surface waves and excitons in ZnO up to 430 K. New Journal of Physics, 23(9), 093031.
  Henn, S.; Grundmann, M. & Sturm, C.
  
• Strong coupling of Bloch Surface Waves to excitons in ZnO, 13th Annual BuildMoNa Conference, (online), 2021 (Poster).
  S. Henn, M. Grundmann & C. Sturm
  
• Propagation And Manipulation Of Bloch Surface Waves And Bloch Surface Wave Polaritons In ZnO, DPG Spring Meeting, Germany, 2022 (Poster).
  S. Henn, M. Grundmann & C. Sturm
  
• Strong Coupling Of Bloch Surface Waves And Excitons In ZnO Up To 430 K, 13th International Conference on Metamaterials, Photonic Crystals and Plasmonics (META), Spain, 2022 (Poster).
  S. Henn, M. Grundmann & C. Sturm
  
• Imaging Ellipsometry For Photonic Guided Mode Detection, 12th Workshop on Spectroscopic Ellipsometry, Czech Republic, 2023 (Poster, awarded).
  S. Henn, M. Grundmann & C. Sturm
  
• Imaging Ellipsometry For Photonic Guided Mode Detection, 12th Workshop on Spectroscopic Ellipsometry, Czech Republic, 2023 (Talk).
  S. Henn, M. Grundmann & C. Sturm
  
• Optical Grating Couplers For The Excitation Of Bloch Surface Waves, DPG Spring Meeting, Germany, 2023 (Poster).
  S. Henn, M. Grundmann & C. Sturm
  
• Strongly Coupled Bloch Surface Wave Polaritons In ZnO Above Room Temperature, Annual Build MoNa Conference, Germany, 2023 (Poster).
  S. Henn, M. Grundmann & C. Sturm