Bleckmann, Felix: Controlling surface plasmon polaritons with dielectric nanostructures. - Bonn, 2016. - Dissertation, Rheinische Friedrich-Wilhelms-Universität Bonn.

Online-Ausgabe in bonndoc: https://nbn-resolving.org/urn:nbn:de:hbz:5n-45880

Online-Ausgabe in bonndoc: https://nbn-resolving.org/urn:nbn:de:hbz:5n-45880

@phdthesis{handle:20.500.11811/6947,

urn: https://nbn-resolving.org/urn:nbn:de:hbz:5n-45880,

author = {{Felix Bleckmann}},

title = {Controlling surface plasmon polaritons with dielectric nanostructures},

school = {Rheinische Friedrich-Wilhelms-Universität Bonn},

year = 2016,

month = dec,

note = {This thesis focuses on the investigation of methods to control surface plasmon polaritons (SPPs), i.e., coupled oscillations of electromagnetic waves with the conduction band electrons at the surface of metals.

In the first part, the evolution of so-called Airy SPP beams propagating under influence of a non-vanishing gradient of the effective refractive index is investigated. These beams represent the plasmonic analog to a class of non-diffracting wave packets, named Airy beams. We experimentally demonstrate that by fabricating dielectric wedges on top of a gold layer with negative-tone gray-scale electron beam lithography, Airy SPP beams can be bent in a controlled manner. The evolution of bent Airy SPP beams is observed by making use of leakage radiation microscopy. The results exhibit an excellent agreement to our numerical calculations.

In the second part of this thesis we use dielectric loaded SPP waveguide arrays as quantum simulators. In this context, a Su-Schrieffer-Heeger topological insulator is implemented in the plasmonic system. Such material can provide both, a band structure with a band gap in its bulk material as well as in-gap states, localized at the surface/edge of the system. The waveguide arrays are fabricated on top of a gold layer by negative-tone gray-scale electron beam lithography. The intensity distribution of propagating SPPs in these arrays is then investigated in both, real and Fourier space by making use of leakage radiation microscopy. As a result, a topologically protected edge state is observed as localized state in the real space and as an in-gap state in the Fourier space. All results are in excellent agreement to numerical calculations.

The last part of the thesis is dedicated to the switching of plasmonic systems. For this purpose we make use of photochromic materials, i.e., materials that provide isomers with different complex refractive indices which can be converted into each other by light induced chemical reactions.

In this context, we investigate Fano resonances in photochromic metallic photonic crystal slabs on their behavior by switching the state of a photochromic layer. The Fano resonances are induced by the interaction of localized plasmonic modes in gold wires with extended waveguide modes in the dielectric layer. The corresponding structures are fabricated with positive tone electron beam lithography. By careful adjustment of all parameters we observe a strong blurring of the Fano resonance upon switching the photochromic material. All results are in good agreement to numerical calculations.

Finally, we investigate the influence of a changing real part of the effective refractive index on SPPs propagating along a photochromic-material-gold interface, as induced by photochromic switching. By making use of Fourier space imaging we demonstrate a change of the effective refractive index of the SPPs of approximately 5%. Additionally, first experiments on the manipulation of propagating SPPs by a locally switched photochromic layer are discussed.},

url = {https://hdl.handle.net/20.500.11811/6947}

}

urn: https://nbn-resolving.org/urn:nbn:de:hbz:5n-45880,

author = {{Felix Bleckmann}},

title = {Controlling surface plasmon polaritons with dielectric nanostructures},

school = {Rheinische Friedrich-Wilhelms-Universität Bonn},

year = 2016,

month = dec,

note = {This thesis focuses on the investigation of methods to control surface plasmon polaritons (SPPs), i.e., coupled oscillations of electromagnetic waves with the conduction band electrons at the surface of metals.

In the first part, the evolution of so-called Airy SPP beams propagating under influence of a non-vanishing gradient of the effective refractive index is investigated. These beams represent the plasmonic analog to a class of non-diffracting wave packets, named Airy beams. We experimentally demonstrate that by fabricating dielectric wedges on top of a gold layer with negative-tone gray-scale electron beam lithography, Airy SPP beams can be bent in a controlled manner. The evolution of bent Airy SPP beams is observed by making use of leakage radiation microscopy. The results exhibit an excellent agreement to our numerical calculations.

In the second part of this thesis we use dielectric loaded SPP waveguide arrays as quantum simulators. In this context, a Su-Schrieffer-Heeger topological insulator is implemented in the plasmonic system. Such material can provide both, a band structure with a band gap in its bulk material as well as in-gap states, localized at the surface/edge of the system. The waveguide arrays are fabricated on top of a gold layer by negative-tone gray-scale electron beam lithography. The intensity distribution of propagating SPPs in these arrays is then investigated in both, real and Fourier space by making use of leakage radiation microscopy. As a result, a topologically protected edge state is observed as localized state in the real space and as an in-gap state in the Fourier space. All results are in excellent agreement to numerical calculations.

The last part of the thesis is dedicated to the switching of plasmonic systems. For this purpose we make use of photochromic materials, i.e., materials that provide isomers with different complex refractive indices which can be converted into each other by light induced chemical reactions.

In this context, we investigate Fano resonances in photochromic metallic photonic crystal slabs on their behavior by switching the state of a photochromic layer. The Fano resonances are induced by the interaction of localized plasmonic modes in gold wires with extended waveguide modes in the dielectric layer. The corresponding structures are fabricated with positive tone electron beam lithography. By careful adjustment of all parameters we observe a strong blurring of the Fano resonance upon switching the photochromic material. All results are in good agreement to numerical calculations.

Finally, we investigate the influence of a changing real part of the effective refractive index on SPPs propagating along a photochromic-material-gold interface, as induced by photochromic switching. By making use of Fourier space imaging we demonstrate a change of the effective refractive index of the SPPs of approximately 5%. Additionally, first experiments on the manipulation of propagating SPPs by a locally switched photochromic layer are discussed.},

url = {https://hdl.handle.net/20.500.11811/6947}

}