16 research outputs found
Trends in gezondheid en het belang van zelfredzaamheid bij zelfstandig wonende ouderen. Advies Raad voor de Volksgezondheid & Zorg
This is the author accepted manuscript. The final version is available from American Chemical Society via the DOI in this record.The range of application of diverse graphene-based devices could be limited by insufficient surface
reactivity, unsatisfied shaping, or null energy gap of graphene. Engineering the graphene structure by laser
techniques can adjust transport properties and surface area of graphene, providing devices of different nature
with a higher capacitance. Additionally, the created periodic potential and appearance of the active
external/inner/edge surface centers determine the multifunctionality of the graphene surface and
corresponding devices. Here, we report on the first implementation of nonlinear laser lithography (NLL) for
multilayer graphene (MLG) structuring, which offers a low-cost, single-step, and high-speed
nanofabrication process. The NLL relies on the employment of a high repetition rate femtosecond Yb fiber
laser that provides generation of highly reproducible, robust, uniform and periodic nanostructures over a
large surface area (1 cm2
/15 sec). NLL allows one to obtain clearly pre-designed patterned graphene
structures without fabrication tolerances, caused by contacting mask contamination, polymer residuals and
direct laser exposure of the graphene layers. We represent regularly-patterned multilayer graphene (p-MLG)
obtained by the CVD-method on NLL-structured Ni foil. We also demonstrate tuning of chemical
(wettability) and electro-optical (transmittance and sheet resistance) properties of p-MLG due to laser power
adjustment. In conclusion, we show the great promise of fabricated devices, namely supercapacitors, and
Li-ion batteries by using NLL-assisted graphene patterning. Our approach demonstrates a new avenue to
pattern graphene for multifunctional device engineering in optics, photonics, and bioelectronicsThis research was partially supported by the European Research Council (ERC) Consolidator Grants ERC682723
SmartGraphene and ERC-617521 NLL; the European Union funding: Marie Curie Fellowship
visiting grant; and the Engineering and Physical Sciences Research Council (EPSRC) of the United
Kingdom via Grant No. EP/N035569/1
Ultrafast optics: Nonlinear attraction
International audienceA new femtosecond fibre laser design combines two distinct regimes of nonlinear dynamic attraction within a single cavity to yield robust and low-noise performance
The Influence of CO<sub>2</sub> Admixtures on the Product Composition in a Nitrogen-Methane Atmospheric Glow Discharge Used as a Prebiotic Atmosphere Mimic
This work extends our previous experimental studies of the chemistry of Titan’s atmosphere by atmospheric glow discharge. The Titan’s atmosphere seems to be similarly to early Earth atmospheric composition. The exploration of Titan atmosphere was initiated by the exciting results of the Cassini-Huygens mission and obtained results increased the interest about prebiotic atmospheres. Present work is devoted to the role of CO2 in the prebiotic atmosphere chemistry. Most of the laboratory studies of such atmosphere were focused on the chemistry of N2 + CH4 mixtures. The present work is devoted to the study of the oxygenated volatile species in prebiotic atmosphere, specifically CO2 reactivity. CO2 was introduced to the standard N2 + CH4 mixture at different mixing ratio up to 5 % CH4 and 3 % CO2. The reaction products were characterized by FTIR spectroscopy. This work shows that CO2 modifies the composition of the gas phase with the detection of oxygenated compounds: CO and others oxides. There is a strong influence of CO2 on increasing concentration other products as cyanide (HCN) and ammonia (NH3)
Self-similarity in ultrafast nonlinear optics
Recent developments in nonlinear optics have led to the discovery of a new class of ultrashort pulse, the 'optical similariton'. Optical similaritons arise when the interaction of nonlinearity, dispersion and gain in a high-power fibre amplifier causes the shape of an arbitrary input pulse to converge asymptotically to a pulse whose shape is self-similar. In comparison with optical solitons, which rely on a delicate balance of nonlinearity and anomalous dispersion and which can become unstable with increasing intensity, similaritons are more robust at high pulse powers. The simplicity and widespread availability of the components needed to build a self-similar amplifier capable of producing optical similaritons provides a convenient experimental platform to explore the fundamental nature of dynamical self-similarity. Here, we provide an overview of self-similar pulse propagation and scaling in optical fibre amplifiers, and their use in the development of high-power ultrafast optical sources, pulse synthesis and all-optical pulse regeneration
Self-similarity in ultrafast nonlinear optics
International audienceRecent developments in nonlinear optics have led to the discovery of a new class of ultrashort pulse, the `optical similariton'. Optical similaritons arise when the interaction of nonlinearity, dispersion and gain in a high-power fibre amplifier causes the shape of an arbitrary input pulse to converge asymptotically to a pulse whose shape is self-similar. In comparison with optical solitons, which rely on a delicate balance of nonlinearity and anomalous dispersion and which can become unstable with increasing intensity, similaritons are more robust at high pulse powers. The simplicity and widespread availability of the components needed to build a self-similar amplifier capable of producing optical similaritons provides a convenient experimental platform to explore the fundamental nature of dynamical self-similarity. Here, we provide an overview of self-similar pulse propagation and scaling in optical fibre amplifiers, and their use in the development of high-power ultrafast optical sources, pulse synthesis and all-optical pulse regeneration