Epsilon-near-zero mediated long-range Förster resonance energy transfer process
Pihlava, Tuomas (2020)
2020
Tekniikan ja luonnontieteiden kandidaattiohjelma - Degree Programme in Engineering and Natural Sciences, BSc (Tech)
Tekniikan ja luonnontieteiden tiedekunta - Faculty of Engineering and Natural Sciences
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Hyväksymispäivämäärä
2020-05-12
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tuni-202005085122
https://urn.fi/URN:NBN:fi:tuni-202005085122
Tiivistelmä
Optical metamaterials consisting of unit cells much smaller than the wavelengths of incident light can be used to precisely engineer light-matter interactions. Metamaterials composed of alternating dielectric and metal layers can be used to achieve extraordinary properties, such as propagating high-k waves and epsilon-near-zero (ENZ) behaviour on a certain range of wavelengths.
Förster resonance energy transfer (FRET) is a mechanism of energy transfer between two fluorescent molecules. Typically, FRET takes place when the molecules are separated by no more than 10 nm. However, it has been proposed that a multi-layer nanostructure can be used to achieve over tenfold increase of this range. Furthermore, the physical background of this phenomenon is predominantly unknown. In this thesis, multi-layer nanostructures are studied as a means of mediating FRET over distances much longer than usual Förster distances.
The thesis is divided into two parts. The first part, as the literature review part, concentrates on the properties, fabrication, and applications of multi-layer nanostructures and how they can be used to achieve hyperbolic and ENZ behaviour in a material. Furthermore, a review of photoluminescence and FRET processes is provided. Finally, crucial spectroscopy methods utilized in the experimental part are reviewed.
In the experimental part, the FRET process is studied between two organic dye molecules, Coumarin 485 and LDS 798. The experiments were conducted by steady-state and time-resolved fluorescence spectroscopy measurements. The results demonstrated energy transfer occurring between these molecules. In addition, three multi-layer nanostructures compatible with the mentioned dye molecules were designed based on the introduced theory. The first structure displays dielectric behaviour on the spectral range where FRET takes place. The second structure is an ENZ material and the third one shows hyperbolic behaviour on that range. The results provided in this thesis can be used to conduct a more thorough investigation of FRET mediated by multi-layer nanostructures displaying different optical properties.
Förster resonance energy transfer (FRET) is a mechanism of energy transfer between two fluorescent molecules. Typically, FRET takes place when the molecules are separated by no more than 10 nm. However, it has been proposed that a multi-layer nanostructure can be used to achieve over tenfold increase of this range. Furthermore, the physical background of this phenomenon is predominantly unknown. In this thesis, multi-layer nanostructures are studied as a means of mediating FRET over distances much longer than usual Förster distances.
The thesis is divided into two parts. The first part, as the literature review part, concentrates on the properties, fabrication, and applications of multi-layer nanostructures and how they can be used to achieve hyperbolic and ENZ behaviour in a material. Furthermore, a review of photoluminescence and FRET processes is provided. Finally, crucial spectroscopy methods utilized in the experimental part are reviewed.
In the experimental part, the FRET process is studied between two organic dye molecules, Coumarin 485 and LDS 798. The experiments were conducted by steady-state and time-resolved fluorescence spectroscopy measurements. The results demonstrated energy transfer occurring between these molecules. In addition, three multi-layer nanostructures compatible with the mentioned dye molecules were designed based on the introduced theory. The first structure displays dielectric behaviour on the spectral range where FRET takes place. The second structure is an ENZ material and the third one shows hyperbolic behaviour on that range. The results provided in this thesis can be used to conduct a more thorough investigation of FRET mediated by multi-layer nanostructures displaying different optical properties.
Kokoelmat
- Kandidaatintutkielmat [8997]