Search results for "optoelectronic"
showing 10 items of 2328 documents
In-fiber time-resolved acousto-optics
2014
Time-resolved in-fiber acousto-optics permit the measurement of sub-ppm perturbations of the modal dispersion curves along sections of fiber exceeding 1 m long, with a spatial resolution in the order of few cm.
Extremely efficient evaluation of chromatic dispersion in realistic photonic crystal fibers
2004
We present a fast and accurate procedure for the evaluation of chromatic dispersion in photonic crystal fibers. It combines an iterative Fourier technique to compute the propagation constant at any fixed wavelength and an analytical approach to calculate its derivatives.
Suppression of pulse pedestal using nonlinear optical loop mirrors in grating-compensated dispersion-managed fiber transmission systems
2006
Pulse pedestal suppression by nonlinear optical loop mirrors is utilized to reduce the intersymbol interference caused by the group delay ripples of a real grating profile in dispersion-managed communication systems compensated by chirped fiber gratings.
Giant Enhancement in the Supercapacitance of NiFe–Graphene Nanocomposites Induced by a Magnetic Field
2019
The rapid rise in energy demand in the past years has prompted a search for low-cost alternatives for energy storage, supercapacitors being one of the most important devices. It is shown that a dramatic enhancement (≈1100%, from 155 to 1850 F g-1 ) of the specific capacitance of a hybrid stimuli-responsive FeNi3 -graphene electrode material can be achieved when the charge/discharge cycling is performed in the presence of an applied magnetic field of 4000 G. This result is related to an unprecedented magnetic-field-induced metal segregation of the FeNi3 nanoparticles during the cycling, which results in the appearance of small Ni clusters (<5 nm) and, consequently, in an increase in pseudoca…
Dielectric-loaded plasmonic waveguide components: Going practical
2013
Surface plasmon propagating modes supported by metal/dielectric interfaces in various configurations can be used for radiation guiding similarly to conventional dielectric waveguides. Plasmonic waveguides offer two attractive features: subdiffraction mode confinement and the presence of conducting elements at the mode-field maximum. The first feature can be exploited to realize ultrahigh density of nanophotonics components, whereas the second feature enables the development of dynamic components controlling the plasmon propagation with ultralow signals, minimizing heat dissipation in switching elements. While the first feature is yet to be brought close to the domain of practical applicatio…
Surface plasmon subwavelength optics.
2003
International audience; Surface plasmons are waves that propagate along the surface of a conductor. By altering the structure of a metal's surface, the properties of surface plasmons- in particular their interaction with light-can be tailored, which offers the potential for developing new types of photonic device. This could lead to miniaturized photonic circuits with length scales that are much smaller than those currently achieved. Surface plasmons are being explored for their potential in subwavelength optics, data storage, light generation, microscopy and bio-photonics.
Spatial carrier distribution in InP/GaAs type II quantum dots and quantum posts
2011
We performed a detailed investigation of the structural and optical properties of multi-layers of InP/GaAs quantum dots, which present a type II interface arrangement. Transmission electronic microscopy analysis has revealed relatively large dots that coalesce forming so-called quantum posts when the GaAs layer between the InP layers is thin. We observed that the structural properties and morphology affect the resulting radiative lifetime of the carriers in our systems. The carrier lifetimes are relatively long, as expected for type II systems, as compared to those observed for single layer InP/GaAs quantum dots. The interface intermixing effect has been pointed out as a limiting factor for…
Electron-induced limitation of surface plasmon propagation in silver nanowires
2013
Plasmonic circuitry is considered as a promising solution-effective technology for miniaturizing and integrating the next generation of optical nano-devices. A key element is the shared metal network between electrical and optical information enabling an efficient hetero-integration of an electronic control layer and a plasmonic data link. Here, we investigate to what extend surface plasmons and current-carrying electrons interfere in such a shared circuitry. By synchronously recording surface plasmon propagation and electrical output characteristics of single chemically-synthesized silver nanowires we determine the limiting factors hindering the co-propagation of electrical current and sur…
Modelling nanoparticles formation in the plasma plume induced by nanosecond pulsed lasers
2012
International audience; Nanoparticles formation in a laser-induced plasma plume in the ambient air has been investigated by using numerical simulations and physical models. For high irradiances, or for ultrashort laser pulses, nanoparticles are formed by condensation, as fine powders, in the expanding plasma for very high pairs of temperature and pressure. At lower irradiances, or nanosecond laser pulses, another thermodynamic paths are possible, which cross the liquid-gas transition curve while laser is still heating the target and the induced plasma. In this work, we explore the growth of nanoparticles in the plasma plume induced by nanosecond pulsed lasers as a function of the laser irra…
Fast-Response Single-Nanowire Photodetector Based on ZnO/WS 2 Core/Shell Heterostructures
2018
This work was supported by the Latvian National Research Program IMIS2 and ISSP project for Students and Young Researchers Nr. SJZ/2016/6. S.P. is grateful to the ERA.Net RUS Plus WATERSPLIT project no. 237 for the financial support. S.V. is grateful for partial support by the Estonian Science Foundation grant PUT1689.