Educação matemática pela arte
Gusmão, Lucimar Donizete
2013-08-28
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103,268 records were found.
The realisation of Gallium-diffused planar waveguides in sapphire is reported. Their characterisation is discussed along with their potential application for the fabrication and optimisation of active devices in sapphire.
We describe the fabrication and use of double-clad and tapered planar waveguide structures for compact and simple, longitudinally-diode-pumped, near-diffraction-limited laser sources with output powers >1W.
Planar photonic crystals comprised of metals and dielectrics show huge enhancements in the surface-enhanced Raman scattering of attached molecules. Plasmon engineering is key to these properties including reproducibility (std.dev.<9%), beamed output, resonances and orientation.
We describe a compact, pulsed, broadband source for sensing using ASE from Er gas detection.
We describe the first non-destructive measurements of the evolution of the optical continuum along a non-linear waveguide. By utilizing near-field microscopy, the spectral variation can be imaged along and across the waveguide with sub-wavelength resolution.
An optical diffraction based sensor has been developed for the detection of DNA-gold nanoparticle hybrids. Silicon substrates were patterned with oligonucleotide sequences in the form of a one-dimensional diffraction grating. Complementary sequences are detected by hybridisation with an oligonucleotide functionalised gold nanoparticle label. Detection of the gold nanoparticles is achieved by examining the diffraction efficiency of the diffraction gratings formed by laser illumination.
Combined electrochemical and planar waveguide surface plasmon resonance measurements demonstrating the oxidative desorption through cyclic voltammetry in acid of an alkane thiol monolayer from a gold film are presented in this paper. We show that the thiol film can be systematically removed and we investigate the oxidative mechanism using both a gold wire and evaporated gold on Pyrex surfaces. For the latter we use a combined planar waveguide surface plasmon resonance (SPR) and electrochemical sensor, where the gold pad acts as both the sensing area for SPR measurements and the electrode for electrochemical investigations. The results show a linear relationship between the fractional coverage of the gold electrode and the transmission measured using SPR, and these results are compared to the results of a numerical simulation. This sens...
The extraordinary progress of optical communications over the last decade or so has led some commentators to suggest that the photonics community has done too good a job in satisfying the demand for bandwidth. In hindsight, historians and economists will point out that a glut of any commodity, in this case bandwidth, inevitably results in a crash in the market. While this may be the case at present, the underlying growth in optical telecommunication remains firm and will surely eventually stabilise. The challenge is to develop the technologies that will be required once the market returns. It is very clear that cost is the next challenge. For the first time, many research laboratories have scaled back their advanced work on 40Gbit/s systems and above, multi-wavelength terabit transmission and large-scale optical switches to focus on lo...
