| 1. |
- Lodewijks, Kristof, 1984, et al.
(författare)
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Magnetoplasmonic Design Rules for Active Magneto-Optics
- 2014
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Ingår i: Nano letters. - : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 14:12, s. 7207-7214
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Tidskriftsartikel (refereegranskat)abstract
- Light polarization rotators and nonreciprocal optical isolators are essential building blocks in photonics technology. These macroscopic passive devices are commonly based on magneto-optical Faraday and Kerr polarization rotation. Magnetoplasmonics, the combination of magnetism and plasmonics, is a promising route to bring these devices to the nanoscale. We introduce design rules for highly tunable active magnetoplasmonic elements in which we can tailor the amplitude and sign of the Kerr response over a broad spectral range.
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| 2. |
- Pettersson, Håkan, 1962-, et al.
(författare)
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Electrical and optical properties of InP nanowire ensemble p(+)-i-n(+) photodetectors
- 2012
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Ingår i: Nanotechnology. - Bristol, UK : Institute of Physics Publishing (IOPP). - 0957-4484 .- 1361-6528. ; 23:13
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Tidskriftsartikel (refereegranskat)abstract
- We report on a comprehensive study of electrical and optical properties of efficient near-infrared p(+)-i-n(+) photodetectors based on large ensembles of self-assembled, vertically aligned i-n(+) InP nanowires monolithically grown on a common p(+) InP substrate without any buffer layer. The nanowires have a polytype modulated crystal structure of wurtzite and zinc blende. The electrical data display excellent rectifying behavior with an ideality factor of about 2.5 at 300 K. The ideality factor scales with 1/T, which possibly reflects deviations from classical transport models due to the mixed crystal phase of the nanowires. The observed dark leakage current is of the order of merely similar to 100 fA/nanowire at 1 V reverse bias. The detectors display a linear increase of the photocurrent with reverse bias up to about 10 pA/nanowire at 5 V. From spectrally resolved measurements, we conclude that the photocurrent is primarily generated by funneling photogenerated carriers from the substrate into the NWs. Contributions from direct excitation of the NWs become increasingly important at low temperatures. The photocurrent decreases with temperature with an activation energy of about 50 meV, which we discuss in terms of a temperature-dependent diffusion length in the substrate and perturbed transport through the mixed-phase nanowires. © 2012 IOP Publishing Ltd.
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| 3. |
- Zubritskaya, Irina, 1984, et al.
(författare)
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Active magnetoplasmonic ruler
- 2015
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Ingår i: Nano letters. - : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 15:5, s. 3204-3211
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Tidskriftsartikel (refereegranskat)abstract
- Plasmon rulers are an emerging concept in which the strong near-field coupling of plasmon nanoantenna elements is employed to obtain structural information at the nanoscale. Here, we combine nanoplasmonics and nanomagnetism to conceptualize a magnetoplasmonic dimer nanoantenna that would be able to report nanoscale distances while optimizing its own spatial orientation. The latter constitutes an active operation in which a dynamically optimized optical response per measured unit length allows for the measurement of small and large nanoscale distances with about 2 orders of magnitude higher precision than current state-of-the-art plasmon rulers. We further propose a concept to optically measure the nanoscale response to the controlled application of force with a magnetic field.
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| 4. |
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| 5. |
- Zubritskaya, Irina, 1984
(författare)
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Active magnetoplasmonics for nanoscale distances sensing
- 2015
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Magnetoplasmonics is an emerging field within nano-photonics that operates with the combination of propagating or localized surface plasmons and magnetism. Active and adaptive magnetoplasmonic components that are capable of controlling light on the nanoscale with external weak magnetic fields are envisioned to push the development of integrated photonic circuits, high-density data storage, or the advanced schemes for bio- and chemo-sensing. In these components plasmon-enhanced and controlled magneto-optical activity creates a new way of active control of plasmonic devices.In this thesis we investigate the role of localized surface plasmons on magneto-optical activity and demonstrate how magnetoplasmonics can be employed in the optical detection of nanoscale distances. Plasmon rulers are an emerging concept in which the strong near-field coupling of plasmon nanoantenna elements is employed to obtain structural information at the nanoscale. We introduce an active magnetoplasmonic ruler that provides active operation and nanoscale distances reading with the figure-of-merit substantially exceeding the one of traditional plasmon rulers. We combine nanoplasmonics and nanomagnetism to conceptualize a magnetoplasmonic dimer nanoantenna that would be able to report nanoscale distances while optimizing its own spatial orientation. The latter constitutes an active operation, in which a dynamically optimized optical response per measured unit length allows for the measurement of small and large nanoscale distances with about two orders of magnitude higher precision than current state-of-the-art plasmon rulers.
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| 6. |
- Zubritskaya, Irina, 1984
(författare)
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Designer magnetoplasmonics for adaptive nano-optics
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Materials that provide real-time control of the fundamental properties of light at visible and near-infrared frequencies enable the essential components for future optical devices. Metal nanostructures that couple electromagnetic (EM) radiation on a sub-wavelength length scale to free electrons, forming propagating or localized surface plasmons, provide many exciting functionalities due to their ability to manipulate light via the local EM field shaping and enhancement. Magnetoplasmonics is an emerging field within nano-optics that operates with the combination of propagating or localized surface plasmons and magnetism. Active and adaptive magnetoplasmonic components capable of controlling light on the nanoscale with externally applied magnetic fields are envisioned to push the development of integrated photonic circuits, high-density data storage, or the advanced schemes for bio- and chemo-sensing. In these components plasmon-enhanced and controlled magneto-optical activity creates a new way of control for plasmonic devices, which is explored in this thesis. Another focus of this thesis are chiral plasmonic materials that exhibit an enhanced chiroptical response due to the nanoconfinement of light and strong near-field coupling. These have benefits in applications like chiral sensing. Fundamentally, they offer an additional degree of freedom to control the phase and polarization of light on the sub-wavelength scale via interaction with its helicity, i.e., angular momentum. Adaptive chiral materials provide a new pathway for real-time control of chiral light’s scattering and absorption by weak magnetic fields. Engineering of chiral materials that can manipulate the helicity of light is decisive for angular momentum-controlled nanophotonics. A general topic of this thesis is the design and fabrication of advanced optical nanoantennas, used to dynamically manipulate light. Among applications are nanorulers, adaptive magneto-chiral and highly transparent magneto-dielectric surfaces.
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| 7. |
- Zubritskaya, Irina, 1984, et al.
(författare)
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Dynamically Tunable Optical Cavities with Embedded Nematic Liquid Crystalline Networks
- 2023
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Ingår i: Advanced Materials. - : Wiley. - 0935-9648 .- 1521-4095. ; 35:13
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Tidskriftsartikel (refereegranskat)abstract
- Tunable metal–insulator–metal (MIM) Fabry–Pérot (FP) cavities that can dynamically control light enable novel sensing, imaging and display applications. However, the realization of dynamic cavities incorporating stimuli-responsive materials poses a significant engineering challenge. Current approaches rely on refractive index modulation and suffer from low dynamic tunability, high losses, and limited spectral ranges, and require liquid and hazardous materials for operation. To overcome these challenges, a new tuning mechanism employing reversible mechanical adaptations of a polymer network is proposed, and dynamic tuning of optical resonances is demonstrated. Solid-state temperature-responsive optical coatings are developed by preparing a monodomain nematic liquid crystalline network (LCN) and are incorporated between metallic mirrors to form active optical microcavities. LCN microcavities offer large, reversible and highly linear spectral tuning of FP resonances reaching wavelength-shifts up to 40 nm via thermomechanical actuation while featuring outstanding repeatability and precision over more than 100 heating–cooling cycles. This degree of tunability allows for reversible switching between the reflective and the absorbing states of the device over the entire visible and near-infrared spectral regions, reaching large changes in reflectance with modulation efficiency ΔR = 79%.
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| 8. |
- Zubritskaya, Irina, 1984, et al.
(författare)
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Magnetic control of the chiroptical plasmonic surfaces
- 2018
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Ingår i: Nano letters. - : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 18:1, s. 302-307
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Tidskriftsartikel (refereegranskat)abstract
- A major challenge facing plasmon nanophotonics is the poor dynamic tunability. A functional nanophotonic element would feature the real-time sizeable tunability of transmission, reflection of light’s intensity or polarization over a broad range of wavelengths, and would be robust and easy to integrate. Several approaches have been explored so far including mechanical deformation, thermal or refractive index effects, and all-optical switching. Here we devise an ultra-thin chiroptical surface, built on 2D nanoantennas, where the chiral light transmission is controlled by the externally applied magnetic field. The magnetic field-induced modulation of the far-field chiroptical response with this surface exceeds 100% in the visible and near-infrared spectral ranges, opening the route for nanometer-thin magnetoplasmonic light-modulating surfaces tuned in real time and featuring a broad spectral response.
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