Search results for " Optics"
showing 10 items of 5880 documents
Fabrication-friendly polarization-sensitive plasmonic grating for optimal surface-enhanced Raman spectroscopy
2020
Plasmonic nanostructures are widely utilized in surface-enhanced Raman spectroscopy (SERS) from ultraviolet to near-infrared applications. Periodic nanoplasmonic systems such as plasmonic gratings are of great interest as SERS-active substrates due to their strong polarization dependence and ease of fabrication. In this work, we modelled a silver grating that manifests a subradiant plasmonic resonance as a dip in its reflectivity with significant near-field enhancement only for transverse-magnetic (TM) polarization of light. We investigated the role of its fill factor, commonly defined as a ratio between the width of the grating groove and the grating period, on the SERS enhancement. We des…
Skin Parameter Map Retrieval from a Dedicated Multispectral Imaging System Applied to Dermatology/Cosmetology
2013
International audience; In vivo quantitative assessment of skin lesions is an important step in the evaluation of skin condition. An objective measurement device can help as a valuable tool for skin analysis. We propose an explorative new multispectral camera specifically developed for dermatology/cosmetology applications. The multispectral imaging system provides images of skin reflectance at different wavebands covering visible and near-infrared domain. It is coupled with a neural network-based algorithm for the reconstruction of reflectance cube of cutaneous data. This cube contains only skin optical reflectance spectrum in each pixel of the bidimensional spatial information. The reflect…
Purcell Enhancement and Wavelength Shift of Emitted Light by CsPbI3 Perovskite Nanocrystals Coupled to Hyperbolic Metamaterials
2020
Manipulation of the exciton emission rate in nanocrystals of lead halide perovskites (LHPs) was demonstrated by means of coupling of excitons with a hyperbolic metamaterial (HMM) consisting of alternating thin metal (Ag) and dielectric (LiF) layers. Such a coupling is found to induce an increase of the exciton radiative recombination rate by more than a factor of three due to the Purcell effect when the distance between the quantum emitter and HMM is nominally as small as 10 nm, which coincides well with the results of our theoretical analysis. Besides, an effect of the coupling-induced long wavelength shift of the exciton emission spectrum is detected and modeled. These results can be of i…
Validation of 2D Force Measurement Roller Ski and Practical Application.
2022
Several methods could be used to measure the forces from skis or roller skis in cross-country skiing. Equipment that could measure medio-lateral forces may be of good help for investigating the relevant skating techniques. The aim of this study was to validate a pair of newly designed two-dimensional force measurement roller skis. The vertical and medio-lateral forces which were perpendicular to the body of the roller ski could be measured. Forces were resolved into the global coordinate system and compared with the force components measured by a force plate. A static and dynamic loading situation for the force measurement roller ski was performed to reveal the validity of the system. To de…
Preliminary analysis of CH3D from 3250 to 3700 cm(-1)
2006
International audience; The infrared spectrum of CH3D from 3250 to 3700 cm(-1) was studied for the first time to assign transitions involving the nu(2) + nu(3), nu(2) + nu(5), nu(2) + nu(6), nu(3) + 2(nu 6) and 3 nu(6) vibrational states. Line positions and intensities were measured at 0.011 cm(-1) resolution using Fourier transform spectra recorded at Kitt Peak with isotopically enriched samples. Some 2852 line positions (involving over 900 upper state levels) and 874 line intensities were reproduced with RMS values of 0.0009 cm(-1) and 4.6%, respectively. The strongest bands were found to be nu(2) + nu(3) at 3499.7 cm(-1) and nu(2) + nu(6) at 3342.5 cm(-1) with integrated strengths, respe…
Design and simulation of QCA-based 3-bit binary to gray and vice versa code converter in reversible and non-reversible mode
2022
The current Very Large-Scale Integration (VLSI) technology has reached its peak due to the fundamental physical limits of Complementary Metal-Oxide-Semiconductor (CMOS). Quantum-dot Cellular Automata (QCA) is considered a proper alternative to CMOS technology in digital circuit design. QCA has features like low power, small area, and high speed in nanoscale digital circuit design. A code converter is a circuit that converts a determined code to another one. Code converters such as Binary to Gray, Gray to Binary, and Binary to BCD converters have a crucial role in fast signal processing in digital systems. Also, code converters are used as a base unit for data transmission into the Arithmeti…
Clinical Assessment of the Effects of Low-Level Laser Therapy on Coronally Advanced Flap Procedure in the Management of Isolated Gingival Recession
2022
The aim of this randomized, controlled split-mouth clinical trial was to assess the effect of LLLT on wound healing after modified coronally advanced flap (MCAF) procedure for treatment of isolated recession-type defects. Fifteen patients with isolated bilaterally symmetrical gingival recessions (Miller’s Class I or Class II, or a combination of both) were enrolled in this study. After a modified, coronally advanced flap technique was implemented, a diode laser (810 nm) with a power of 120 mW irradiated the inner surface of the flap and the outer surface of the flap (low-level laser therapy—LLLT) after suturing for 5 min. This was repeated for the following four consecutive days…
When the Grafting of Double Decker Phthalocyanines on Si(100)-2 × 1 Partly Affects the Molecular Electronic Structure
2016
International audience; A combined X-ray photoelectron spectroscopy (XPS), scanning tunneling microscopy (STM), and density functional theory (DFT) study has been performed to characterize the adsorbate interaction of lutetium biphthalocyanine (LuPc2) molecules on the Si(100)-2 × 1 surface. Large molecule–substrate adsorption energies are computed and are found to compete with the molecule–molecule interactions of the double decker molecules. A particularly good matching between STM images and computed ones confirms the deformation of the molecule upon the absorption process. The comparison between DFT calculations and XP spectra reveals that the electronic distribution in the two plateaus …
Folate targeted coated SPIONs as efficient tool for MRI
2017
The development of more sensitive diagnostic tools allowing an early-stage and highly efficient medical imaging of tumors remains a challenge. Magnetic nanoparticles seem to be the contrast agents with the highest potential, if properly constructed. Therefore, in this study, hybrid magnetic nanoarchitectures were developed using a new amphiphilic inulin-based graft copolymer (INU-LAPEG-FA) as coating material for 10-nm spinel iron oxide (magnetite, Fe3O4) superparamagnetic nanoparticles (SPION). Folic acid (FA) covalently linked to the coating copolymer in order to be exposed onto the nanoparticle surface was chosen as the targeting agent because folate receptors are upregulated in many can…