Experimental demonstration of multi-watt CW supercontinuum tailoring in photonic crystal fibers

We demonstrate experimentally that the spectral broadening of CW supercontinuum can be controlled by using photonic crystal fibers with two zero-dispersion wavelengths pumped by an Yb fiber laser at 1064 nm. The spectrum is bounded by two dispersive waves whose spectral location depends on the two zero-dispersion wavelengths of the fiber. The bandwidth of the generated spectrum and the spectral power density may thus be tailored for particular applications, such as high-resolution optical coherence tomography or optical spectroscopy.Comment: 14 preprint pages, 2 figures, 1 tabl

The second-​harmonic generation in chalcogenide glass-​ceramic doped with CdS nanocrystals

International audienceAn innovative way is proposed here to synthesize chalcogenide glass-​CdS nanocrystal composites by hot-​pressing a combination of Ge20Sb12S68 glassy powder and nonlinear CdS nanoparticles. The cadmium sulfide nanoparticles, which possess the second-​harmonic generation property, were synthesized from basic cadmium soln. strongly complexed by amine. The obtained nanocomposites present a homogeneous distribution of the crystals. The transmission reaches 30​% at 5 μm and up to 60​% at 10.6 μm. The second-​harmonic generation at 0.9 μm has been detected. This technique can overcome the uncontrollable hetero-​crystn. which tends to occur in the glass-​ceramics prepd. by the conventional thermal treatment method

Correlation between multiple modulation instability side lobes in dispersion oscillating fiber

We investigate numerically and experimentally the spectral correlation between multiple modulation instability (MI) side lobes in a dispersion oscillating fiber. By leveraging the dispersive Fourier transformation, we acquire instantaneous spectra and investigate the energy correlation between individual MI sidebands through scattergrams. We found that conjugate MI side lobes are strongly correlated while other combinations experience a very low degree of correlation, revealing that parametric processes related to each side lobe pair act quasi-independently.published_or_final_versio

Sensitivity of photonic crystal fiber modes to temperature, strain and external refractive index

Several strong narrowband resonances are observed in the transmission spectra of fiber Bragg gratings photo-written in photonic crystal fiber that has a refractive index-neutral germanium/fluorine co-doped core. Experimental results for the strain, temperature and refractive index sensitivities of these mode resonances are reported and compared to those of conventional single mode fiber. In particular, we identify three kinds of resonances whose relative sensitivities to strain, temperature and refractive index are markedly different and present numerical simulations to explain these properties. Potential multiparameter optical sensor applications of these mode resonances are briefly discussed

O papel social e economica da mulher imigrante na região de Venda Nova do Imigrante (ES) - 1891 A 1927

Dissertação apresentada no Pragrma de Pós- Graduação de Históri

Optical and structural properties of new chalcohalide glasses

New class of chalcohalide glasses has been prepared in the GeS2–In2S3–CsI system with regard to their potential non-linear properties. The study of glass-forming region was undertaken to select glassy compositions, which present high non-linear (NL) optical properties with a low two-photon absorption. Thermal analyses, structural examination by Raman spectroscopy, non-linear optical measurements were investigated as a function of CsI contents. Introduction of CsI has shifted the band-gap edge towards the blue region of the absorption optical spectrum and therefore has limited the two-photon absorption. Their NL refractive index n2 are 60 times higher than silica glasses without any NL absorption. Moreover, second harmonic signal was observed in thermally poled samples similar to silica glass. However, this second order non-linearity is not temporally stable

Second-Order Nonlinear Susceptibility In As2S3 Chalcogenide Thin Glass Films

As2Sb3 chalcogenide thin glass films are investigated when a second-order nonlinear susceptibility χ(2) is induced to the glasses. Both thermal poling and optical poling are used to induced this nonlinearity. In both cases, the magnitude of the χ333 coefficient is estimated to be \u3e0.6 pm/V