Nanoscale electric and magnetic optical vector fields: mapping & injection

Boris le Feber

Abstract

Nanophotonic structures, which offer a sub-wavelength control over light and nearby emitters, promise to advance, for example, our ability to harvest light, process information and detect (bio-) chemical compounds. In general, the optical field distributions near nanophotonic structures are much more complex than those in the far field. That is, nanophotonic structures achieve much of their unique functionalities because both the electromagnetic fields and the emission modification of nearby emitters spatially vary on the nanoscale with respect to their orientation, amplitude and phase. Furthermore, unlike for conventional microscopic structures, the interaction between the optical magnetic fields and nanophotonics structures frequently plays an important role. Hence, an understanding of light-matter interactions at the nanoscale requires a method to spatially map nanoscale electric and magnetic optical vector fields and the emission modification of electric and magnetic dipole emitters. This thesis demonstrates that an aperture type near-field microscope can be used to achieve such a mapping. Firstly, we use the microscope to map the electric and magnetic optical fields of the photonic mode in a benchmark structure, a photonic crystal waveguide. Then, in both the electric and magnetic optical fields we identify points where a property of the field is undefined; optical singularities. For example, we identify polarization singularities, where the light is circularly polarized and the local orientation of the local polarization ellipse is undefined. We measure the local helicity of the circularly polarized light and we trace the position of the singularities in three-dimensional space. Finally, we use the near-field microscope to mimic the emission modification of dipolar emitters and circularly polarized dipoles in particular. We show that the handedness of electric and magnetic circular dipoles, in combination with the local helicity of the photonic mode, can determine the direction of the light emitted into the waveguide. Additionally, we demonstrate that the optical wavelength can be used to tune the positions of efficient helicity-to-path coupling.
Original languageEnglish
Awarding Institution
  • University of Twente
Supervisors/Advisors
  • Supervisor
Date of Award30 Jan 2015
Place of PublicationEnschede
Publisher
Print ISBNs978-94-6259-491-3
StatePublished - 30 Jan 2015

Fingerprint

emitters
microscopes
photonics
near fields
dipoles
waveguides
handedness
chemical compounds
theses
ellipses
polarization
magnetic dipoles
wavelengths
polarized light
electric dipoles
far fields
electromagnetic fields
apertures
interactions
injection

Keywords

  • METIS-309347
  • IR-96339

Cite this

le Feber, B. (2015). Nanoscale electric and magnetic optical vector fields: mapping & injection Enschede: Universiteit Twente
le Feber, Boris. / Nanoscale electric and magnetic optical vector fields: mapping & injection. Enschede : Universiteit Twente, 2015. 140 p.
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abstract = "Nanophotonic structures, which offer a sub-wavelength control over light and nearby emitters, promise to advance, for example, our ability to harvest light, process information and detect (bio-) chemical compounds. In general, the optical field distributions near nanophotonic structures are much more complex than those in the far field. That is, nanophotonic structures achieve much of their unique functionalities because both the electromagnetic fields and the emission modification of nearby emitters spatially vary on the nanoscale with respect to their orientation, amplitude and phase. Furthermore, unlike for conventional microscopic structures, the interaction between the optical magnetic fields and nanophotonics structures frequently plays an important role. Hence, an understanding of light-matter interactions at the nanoscale requires a method to spatially map nanoscale electric and magnetic optical vector fields and the emission modification of electric and magnetic dipole emitters. This thesis demonstrates that an aperture type near-field microscope can be used to achieve such a mapping. Firstly, we use the microscope to map the electric and magnetic optical fields of the photonic mode in a benchmark structure, a photonic crystal waveguide. Then, in both the electric and magnetic optical fields we identify points where a property of the field is undefined; optical singularities. For example, we identify polarization singularities, where the light is circularly polarized and the local orientation of the local polarization ellipse is undefined. We measure the local helicity of the circularly polarized light and we trace the position of the singularities in three-dimensional space. Finally, we use the near-field microscope to mimic the emission modification of dipolar emitters and circularly polarized dipoles in particular. We show that the handedness of electric and magnetic circular dipoles, in combination with the local helicity of the photonic mode, can determine the direction of the light emitted into the waveguide. Additionally, we demonstrate that the optical wavelength can be used to tune the positions of efficient helicity-to-path coupling.",
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author = "{le Feber}, Boris",
year = "2015",
month = "1",
isbn = "978-94-6259-491-3",
publisher = "Universiteit Twente",
school = "University of Twente",

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le Feber, B 2015, 'Nanoscale electric and magnetic optical vector fields: mapping & injection', University of Twente, Enschede.

Nanoscale electric and magnetic optical vector fields: mapping & injection. / le Feber, Boris.

Enschede : Universiteit Twente, 2015. 140 p.

Research output: ScientificPhD Thesis - Research external, graduation UT

TY - THES

T1 - Nanoscale electric and magnetic optical vector fields: mapping & injection

AU - le Feber,Boris

PY - 2015/1/30

Y1 - 2015/1/30

N2 - Nanophotonic structures, which offer a sub-wavelength control over light and nearby emitters, promise to advance, for example, our ability to harvest light, process information and detect (bio-) chemical compounds. In general, the optical field distributions near nanophotonic structures are much more complex than those in the far field. That is, nanophotonic structures achieve much of their unique functionalities because both the electromagnetic fields and the emission modification of nearby emitters spatially vary on the nanoscale with respect to their orientation, amplitude and phase. Furthermore, unlike for conventional microscopic structures, the interaction between the optical magnetic fields and nanophotonics structures frequently plays an important role. Hence, an understanding of light-matter interactions at the nanoscale requires a method to spatially map nanoscale electric and magnetic optical vector fields and the emission modification of electric and magnetic dipole emitters. This thesis demonstrates that an aperture type near-field microscope can be used to achieve such a mapping. Firstly, we use the microscope to map the electric and magnetic optical fields of the photonic mode in a benchmark structure, a photonic crystal waveguide. Then, in both the electric and magnetic optical fields we identify points where a property of the field is undefined; optical singularities. For example, we identify polarization singularities, where the light is circularly polarized and the local orientation of the local polarization ellipse is undefined. We measure the local helicity of the circularly polarized light and we trace the position of the singularities in three-dimensional space. Finally, we use the near-field microscope to mimic the emission modification of dipolar emitters and circularly polarized dipoles in particular. We show that the handedness of electric and magnetic circular dipoles, in combination with the local helicity of the photonic mode, can determine the direction of the light emitted into the waveguide. Additionally, we demonstrate that the optical wavelength can be used to tune the positions of efficient helicity-to-path coupling.

AB - Nanophotonic structures, which offer a sub-wavelength control over light and nearby emitters, promise to advance, for example, our ability to harvest light, process information and detect (bio-) chemical compounds. In general, the optical field distributions near nanophotonic structures are much more complex than those in the far field. That is, nanophotonic structures achieve much of their unique functionalities because both the electromagnetic fields and the emission modification of nearby emitters spatially vary on the nanoscale with respect to their orientation, amplitude and phase. Furthermore, unlike for conventional microscopic structures, the interaction between the optical magnetic fields and nanophotonics structures frequently plays an important role. Hence, an understanding of light-matter interactions at the nanoscale requires a method to spatially map nanoscale electric and magnetic optical vector fields and the emission modification of electric and magnetic dipole emitters. This thesis demonstrates that an aperture type near-field microscope can be used to achieve such a mapping. Firstly, we use the microscope to map the electric and magnetic optical fields of the photonic mode in a benchmark structure, a photonic crystal waveguide. Then, in both the electric and magnetic optical fields we identify points where a property of the field is undefined; optical singularities. For example, we identify polarization singularities, where the light is circularly polarized and the local orientation of the local polarization ellipse is undefined. We measure the local helicity of the circularly polarized light and we trace the position of the singularities in three-dimensional space. Finally, we use the near-field microscope to mimic the emission modification of dipolar emitters and circularly polarized dipoles in particular. We show that the handedness of electric and magnetic circular dipoles, in combination with the local helicity of the photonic mode, can determine the direction of the light emitted into the waveguide. Additionally, we demonstrate that the optical wavelength can be used to tune the positions of efficient helicity-to-path coupling.

KW - METIS-309347

KW - IR-96339

M3 - PhD Thesis - Research external, graduation UT

SN - 978-94-6259-491-3

PB - Universiteit Twente

ER -

le Feber B. Nanoscale electric and magnetic optical vector fields: mapping & injection. Enschede: Universiteit Twente, 2015. 140 p.