• Karl Grundahl Danielsen
  • Jesper Lauritz Winkel Sonne
  • Anders Malthe Westerkam
4. term, Nanotechnology, Master (Master Programme)
This project sets out to fabricate and characterise terahertz photonic components, namely spectral-specific reflectors based on Fano resonances and waveguides utilising photonic crystals. To this end, three theoretical models are implemented to design the structures that exhibit the desired response in the lower end of the terahertz region. These methods are the plane wave expansion, Fourier modal method, and an iterative method based on the fast Fourier transform. The fabrication methods reactive ion etching and laser ablation, which are both readily available in most research and industrial environments, are used to produce the samples. The spectral response of the produced samples is measured using terahertz time-domain spectroscopy. The measured spectra of the structures exhibiting Fano resonances are shown to be in great agreement with the Fourier modal method. An additional model to predict the resonances is developed, and it too proved to be in great agreement with the Fourier modal method. Photonic crystals are fabricated by ablating holes or etching silicon rods in high-resistivity silicon wafers. The photonic crystals are made in both hexagonal and square arrays, and band gaps are shown in the lower end of the terahertz region for both configurations. Solid-core waveguide, and cavity, modes are detected for a hexagonal array of air holes and a hexagonal array of silicon rods, respectively.
SpecialisationNanophysics and -materials
Publication date1 Jun 2022
Number of pages176
ID: 471933944