| 1. |
- Baev, Alexander, et al.
(författare)
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Metaphotonics : An emerging field with opportunities and challenges
- 2015
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Ingår i: Physics reports. - : Elsevier. - 0370-1573 .- 1873-6270. ; 594, s. 1-60
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Forskningsöversikt (refereegranskat)abstract
- Metaphotonics is an emerging multidisciplinary field that deals with manipulation of electro-magnetic fields in nanoengineered (meta)materials using both electric and magnetic interactions and their cross-coupling. It offers unprecedented control of both linear and nonlinear optical functions for applications ranging from optical switching, to negative- and near-zero refractive index metamaterials, to chiral bioimaging, to cloaking. However, realization of such applications requires physics-guided nanoengineering of appropriate artificial media with electro-magnetic properties at visible and infrared wavelengths that are tailored to surpass those of any naturally-occurring material. Here, we review metaphotonics with a broadened vision and scope, introduce potential applications, describe the role of theoretical physics through multiscale modeling, review the materials development and current status, and outline opportunities in this fertile emerging field.
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| 2. |
- Fomin, Alexey, et al.
(författare)
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Fiber Laser Intracavity Spectroscopy of hot water for temperature and concentration measurements
- 2015
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Ingår i: Applied Physics B. - : Springer Science and Business Media LLC. - 0946-2171 .- 1432-0649. ; 121:3, s. 345-351
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Tidskriftsartikel (refereegranskat)abstract
- The feasibility of temperature and concentration measurements using near-IR (similar to 1.5 mu m) water spectra obtained by fiber laser intracavity spectroscopy was evaluated. The spectra were registered with water vapor heated in a tubular oven at temperatures between 1000 and 1300 K and in adiabatic flames where temperatures were above 1800 K. Adiabatic flames of methane were stabilized on the heat flux burner. For temperature and concentration evaluation, the observed spectra were fitted by simulated spectra calculated utilizing the HITEMP database. Several discrepancies between HITEMP data and the experiments leading to significant errors in evaluation were found. After small corrections to the database better, accuracy of the temperature (+/- 70 K) and concentration (+/- 20 %) measurements is obtained. A more precise spectroscopic assignment is needed to improve the accuracy of the results.
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| 3. |
- Lim, Chang-Keun, et al.
(författare)
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Plasmon-enhanced two-photon-induced isomerization for highly-localized light-based actuation of inorganic/organic interfaces
- 2016
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Ingår i: Nanoscale. - : Royal Society of Chemistry. - 2040-3364 .- 2040-3372. ; 8:7, s. 4194-4202
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Tidskriftsartikel (refereegranskat)abstract
- Two-photon initiated photo-isomerization of an azobenzene moiety adsorbed on silver nanoparticles (Ag NPs) is demonstrated. The azobenzene is linked to a materials-binding peptide that brings it into intimate contact with the Ag NP surface, producing a dramatic enhancement of its two-photon absorbance. An integrated modeling approach, combining advanced conformational sampling with Quantum Mechanics/Capacitance Molecular Mechanics and response theory, shows that charge transfer and image charges in the Ag NP generate local fields that enhance two-photon absorption of the cis isomer, but not the trans isomer, of adsorbed molecules. Moreover, dramatic local field enhancement is expected near the localized surface plasmon resonance (LSPR) wavelength, and the LSPR band of the Ag NPs overlaps the azobenzene absorbance that triggers cis to trans switching. As a result, the Ag NPs enable two-photon initiated cis to trans isomerization, but not trans to cis isomerization. Confocal anti-Stokes fluorescence imaging shows that this effect is not due to local heating, while the quadratic dependence of switching rate on laser intensity is consistent with a two-photon process. Highly localized two-photon initiated switching could allow local manipulation near the focal point of a laser within a 3D nanoparticle assembly, which cannot be achieved using linear optical processes.
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