| 1. |
- Caligiuri, Vincenzo, et al.
(författare)
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Dry synthesis of bi-layer nanoporous metal films as plasmonic metamaterial
- 2024
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Ingår i: Nanophotonics. - : Walter de Gruyter. - 2192-8606 .- 2192-8614. ; 13:7, s. 1159-1167
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Tidskriftsartikel (refereegranskat)abstract
- Nanoporous metals are a class of nanostructured materials finding extensive applications in multiple fields thanks to their unique properties attributed to their high surface area and interconnected nanoscale ligaments. They can be prepared following different strategies, but the deposition of an arbitrary pure porous metal is still challenging. Recently, a dry synthesis of nanoporous films based on the plasma treatment of metal thin layers deposited by physical vapour deposition has been demonstrated, as a general route to form pure nanoporous films from a large set of metals. An interesting aspect related to this approach is the possibility to apply the same methodology to deposit the porous films as a multilayer. In this way, it is possible to explore the properties of different porous metals in close contact. As demonstrated in this paper, interesting plasmonic properties emerge in a nanoporous Au–Ag bi-layer. The versatility of the method coupled with the possibility to include many different metals, provides an opportunity to tailor their optical resonances and to exploit the chemical and mechanical properties of components, which is of great interest to applications ranging from sensing, to photochemistry and photocatalysis.
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| 2. |
- Chang, Jin, et al.
(författare)
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Nanowire-based integrated photonics for quantum information and quantum sensing
- 2023
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Ingår i: Nanophotonics. - : Walter de Gruyter GmbH. - 2192-8614 .- 2192-8606. ; 12:3, s. 339-358
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Forskningsöversikt (refereegranskat)abstract
- At the core of quantum photonic information processing and sensing, two major building pillars are single-photon emitters and single-photon detectors. In this review, we systematically summarize the working theory, material platform, fabrication process, and game-changing applications enabled by state-of-the-art quantum dots in nanowire emitters and superconducting nanowire single-photon detectors. Such nanowire-based quantum hardware offers promising properties for modern quantum optics experiments. We highlight several burgeoning quantum photonics applications using nanowires and discuss development trends of integrated quantum photonics. Also, we propose quantum information processing and sensing experiments for the quantum optics community, and future interdisciplinary applications.
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| 3. |
- Dahlin, Andreas, 1980, et al.
(författare)
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Promises and challenges of nanoplasmonic devices for refractometric biosensing
- 2013
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Ingår i: Nanophotonics. - : Walter de Gruyter GmbH. - 2192-8614 .- 2192-8606. ; 2:2, s. 83-101
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Tidskriftsartikel (refereegranskat)abstract
- Optical biosensors based on surface plasmon resonance (SPR) in metallic thin films are currently standard tools for measuring molecular binding kinetics and affinities - an important task for biophysical studies and pharmaceutical development. Motivated by recent progress in the design and fabrication of metallic nanostructures, such as nanoparticles or nanoholes of various shapes, researchers have been pursuing a new generation of biosensors harnessing tailored plasmonic effects in these engineered nanostructures. Nanoplasmonic devices, while demanding nanofabrication, offer tunability with respect to sensor dimension and physical properties, thereby enabling novel biological interfacing opportunities and extreme miniaturization. Here we provide an integrated overview of refractometric biosensing with nanoplasmonic devices and highlight some recent examples of nanoplasmonic sensors capable of unique functions that are difficult to accomplish with conventional SPR. For example, since the local field strength and spatial distribution can be readily tuned by varying the shape and arrangement of nanostructures, biomolecular interactions can be controlled to occur in regions of high field strength. This may improve signal-to-noise and also enable sensing a small number of molecules. Furthermore, the nanoscale plasmonic sensor elements may, in combination with nanofabrication and materials-selective surface-modifications, make it possible to merge affinity biosensing with nanofluidic liquid handling.
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| 4. |
- Davidsson, Joel, 1989-, et al.
(författare)
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Exhaustive characterization of modified Si vacancies in 4H-SiC
- 2022
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Ingår i: Nanophotonics. - : Walter de Gruyter. - 2192-8606 .- 2192-8614. ; 11:20, s. 4565-4580
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Tidskriftsartikel (refereegranskat)abstract
- The negatively charged silicon vacancy (V-Si(-)) in silicon carbide is a well-studied point defect for quantum applications. At the same time, a closer inspection of ensemble photoluminescence and electron paramagnetic resonance measurements reveals an abundance of related but so far unidentified signals. In this study, we search for defects in 4H-SiC that explain the above magneto-optical signals in a defect database generated by automatic defect analysis and qualification (ADAQ) workflows. This search reveals only one class of atomic structures that exhibit silicon-vacancy-like properties in the data: a carbon anti-site (C-Si) within sub-nanometer distances from the silicon vacancy only slightly alters the latter without affecting the charge or spin state. Such a perturbation is energetically bound. We consider the formation of V-Si(-) + C-Si; up to 2 nm distance and report their zero phonon lines and zero field splitting values. In addition, we perform high-resolution photoluminescence experiments in the silicon vacancy region and find an abundance of lines. Comparing our computational and experimental results, several configurations show great agreement. Our work demonstrates the effectiveness of a database with high-throughput results in the search for defects in quantum applications.
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| 5. |
- Hansson, Tobias, 1983, et al.
(författare)
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Dynamics of microresonator frequency comb generation: models and stability
- 2016
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Ingår i: Nanophotonics. - : Walter de Gruyter GmbH. - 2192-8614 .- 2192-8606. ; 5:2, s. 231-243
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Forskningsöversikt (refereegranskat)abstract
- Microresonator frequency combs hold promise for enabling a new class of light sources that are simultaneously both broadband and coherent, and that could allow for a profusion of potential applications. In this article, we review various theoretical models for describing the temporal dynamics and formation of optical frequency combs. These models form the basis for performing numerical simulations that can be used in order to better understand the comb generation process, for example helping to identify the universal combcharacteristics and their different associated physical phenomena. Moreover, models allow for the study, design and optimization of comb properties prior to the fabrication of actual devices. We consider and derive theoretical formalisms based on the Ikeda map, the modal expansion approach, and the Lugiato-Lefever equation. We further discuss the generation of frequency combs in silicon resonators featuring multiphoton absorption and free-carrier effects. Additionally, we review comb stability properties and consider the role of modulational instability as well as of parametric instabilities due to the boundary conditions of the cavity. These instability mechanisms are the basis for comprehending the process of frequency comb formation, for identifying the different dynamical regimes and the associated dependence on the comb parameters. Finally, we also discuss the phenomena of continuous wave bi- and multistability and its relation to the observation of mode-locked cavity solitons.
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| 6. |
- Jayakumar, N, et al.
(författare)
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Multi-moded high-index contrast optical waveguide for super-contrast high-resolution label-free microscopy
- 2022
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Ingår i: Nanophotonics. - : Walter de Gruyter GmbH. - 2192-8606 .- 2192-8614. ; 11:15, s. 3421-3436
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Tidskriftsartikel (refereegranskat)abstract
- The article elucidates the physical mechanism behind the generation of superior-contrast and high-resolution label-free images using an optical waveguide. Imaging is realized by employing a high index contrast multi-moded waveguide as a partially coherent light source. The modes provide near-field illumination of unlabeled samples, thereby repositioning the higher spatial frequencies of the sample into the far-field. These modes coherently scatter off the sample with different phases and are engineered to have random spatial distributions within the integration time of the camera. This mitigates the coherent speckle noise and enhances the contrast (2–10) × as opposed to other imaging techniques. Besides, the coherent scattering of the different modes gives rise to fluctuations in intensity. The technique demonstrated here is named chip-based Evanescent Light Scattering (cELS). The concepts introduced through this work are described mathematically and the high-contrast image generation process using a multi-moded waveguide as the light source is explained. The article then explores the feasibility of utilizing fluctuations in the captured images along with fluorescence-based techniques, like intensity-fluctuation algorithms, to mitigate poor-contrast and diffraction-limited resolution in the coherent imaging regime. Furthermore, a straight waveguide is demonstrated to have limited angular diversity between its multiple modes and therefore, for isotropic sample illumination, a multiple-arms waveguide geometry is used. The concepts introduced are validated experimentally via high-contrast label-free imaging of weakly scattering nanosized specimens such as extra-cellular vesicles (EVs), liposomes, nanobeads and biological cells such as fixed and live HeLa cells.
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| 7. |
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| 8. |
- Larsson, Elin Maria Kristina, 1979, et al.
(författare)
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Nanoplasmonic sensing for nanomaterials science
- 2012
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Ingår i: Nanophotonics. - : Walter de Gruyter GmbH. - 2192-8614 .- 2192-8606. ; 1:3-4, s. 249-266
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Forskningsöversikt (refereegranskat)abstract
- Nanoplasmonic sensing has over the last two decades emerged as and diversified into a very promising experimental platform technology for studies of biomolecular interactions and for biomolecule detection (biosensors). Inspired by this success, in more recent years, nanoplasmonic sensing strategies have been adapted and tailored successfully for probing functional nanomaterials and catalysts in situ and in real time. An increasing number of these studies focus on using the localized surface plasmon resonance (LSPR) as an experimental tool to study a process of interest in a nanomaterial, with a materials science focus. The key assets of nanoplasmonic sensing in this area are its remote readout, non-invasive nature, single particle experiment capability, ease of use and, maybe most importantly, unmatched flexibility in terms of compatibility with all material types (particles and thin/thick layers, conductive or insulating) are identified. In a direct nanoplasmonic sensing experiment the plasmonic nanoparticles are active and simultaneously constitute the sensor and the studied nano-entity. In an indirect nanoplasmonic sensing experiment the plasmonic nanoparticles are inert and adjacent to the material of interest to probe a process occurring in/on this material. In this review we define and discuss these two generic experimental strategies and summarize the growing applications of nanoplasmonic sensors as experimental tools to address materials science-related questions.
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| 9. |
- Leosson, K., et al.
(författare)
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Ultra-thin gold films on transparent polymers
- 2013
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Ingår i: Nanophotonics. - : Walter de Gruyter GmbH. - 2192-8614 .- 2192-8606. ; 2:1, s. 3-11
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Tidskriftsartikel (refereegranskat)abstract
- Fabrication of continuous ultra-thin gold films (
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| 10. |
- Mante, Pierre Adrien, et al.
(författare)
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Acoustic phonons in nanowires probed by ultrafast pump-probe spectroscopy
- 2018
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Ingår i: Nanophotonics. - : Walter de Gruyter GmbH. - 2192-8614 .- 2192-8606. ; 7:11, s. 1759-1780
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Tidskriftsartikel (refereegranskat)abstract
- The fascinating relationship between structure and property in nanowires has enabled a wealth of applications in photonics and electronics. The behavior of phonons in nanowires is also modified compared to their bulk counterparts. In this review, we provide an overview of the recent efforts to investigate the properties of acoustic phonons in nanowires using ultrafast optical methods. In particular, we focus on the calculation of the modified phonon dispersion in nanowires and how to address them optically. We then discuss experimental investigations in arrays of nanowires and a single nanowire. The analysis of phonon behavior reveals the possibility to perform advanced mechanical characterization and to vary the thermal properties of nanowires. The review concludes with a brief perspective on future research directions, from phonon-induced control over properties to three-dimensional (3D) acoustic nano-imaging.
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