55 research outputs found
Mid-infrared two-octave spanning supercontinuum generation in a Ge-Se-Te glass suspended core fiber
International audienc
Linear and Nonlinear Characterizations of Chalcogenide Photonic Crystal Fibers
International audienceIn this paper, we investigate the linear and nonlinear properties of GeSbS and AsSe chalcogenide photonic crystal fibers. Through several experimental setups, we have measured the second- and third-order chromatic dispersion, the effective area, losses, birefringence, the nonlinear Kerr coefficient as well as Brillouin and Raman scattering properties
Accordabilité thermique des interactions ONL: formalisme vectoriel et applications à HGS, KTP et RTP
National audienc
Dispersion and temperature dependence of thermo-optic coefficients of optical materials over their whole transparency range: vectorial formalism and application to KTiOPO4 and HgGa2S4
Optical hysteresis in a semilinear photorefractive coherent oscillator
International audienceHigh contrast optical bistability is found experimentally in the pump-ratio dependences of the output intensity of a semilinear photorefractive coherent oscillator with two counterpropagating pump waves. The data are in qualitative agreement with the results of calculation
Comprehensive formulation of the temperature dependent dispersion of optical materials; illustration with the case of temperature tuning of a mid-IR HgGa2S4 OPO
International audienceThe temperature dependence of refractive indices of optical materials is characterized in this work by what we call their normalized thermo-optic coefficients. These ones are determined experimentally through interferometric measurements of thermal expansion, and changes in optical thickness at a few laser wavelengths as function of temperature. A suitable vectorial formalism applied to these data allows predicting the thermal evolution of the refractive index all over the useful range of transparency. The validity and reliability of our methodology is demonstrated through temperature tuning of a mid-IR HgGa2S4 OPO, pumped at 1.0642 ÎŒm by a Nd:YAG laser. Measured thermal variation of both signal and idler wavelengths agrees very well with the predicted one
Correlation between Molecular Packing and Optical Properties in Different Crystalline Polymorphs and Amorphous Thin Films of mer -Tris(8-hydroxyquinoline)aluminum(III)
International audienc
Flux growth at 1230 °C of cubic Tb2O3 single crystals and characterization of their optical and magnetic properties
In this work, we present the first crystal growth of cubic Tb2O3 single crystals by a controlled atmosphere flux method which uses a heavy metal free solvent working at less than half the melting temperature of this sesquioxide. Cubic millimeter-sized crystals extracted from as-grown boules are phase (powder XRD) and chemically (GDMS) pure and exhibit a Verdet constant in the visible and near-infrared spectral ranges, which is at least three times higher than that of a commercial Tb3Ga5O12 (TGG) crystal. The 1.36 mm thick crystals display a transmission coefficient higher than 77% over the 525 nmâ1.38 ÎŒm spectral range. The absorption spectrum, magnetic susceptibility and specific heat measurements on the single crystals confirm the absence of detectable Tb4+ cations and other impurities
Linear and nonlinear optical properties of MgO:LiTaO3
International audienceWe derive new temperature dependent Sellmeier equations for the extra-ordinary and ordinary refractive indices of 0.5% MgO-doped stoichiometric LiTaO3 crystal. The equations are based on quasi phase-matched frequency conversion measurements, as well as on interferometric measurements of the thermal expansion and thermal dispersion. These equations fit experimental data over wide spectral ranges: 0.35â6 ÎŒm for the extra-ordinary wave and 0.375â3.75 ÎŒm for the ordinary wave, from room temperature up to 200°C. The nonlinear optical measurements set lower-limit values for the d 33, d 22, and d 24 elements of the second-order susceptibility tensor Ï (2) of 12.9, 1.54, and 0.46 pm/V, respectively. The interferometric measurements enable one to determine the linear and quadratic expansion coefficients of 1.45762eâ5 1/°C, and 2.68608eâ8 (1/°C)2, respectively. The Sellmeier equations are in good agreement with previously published data
Second zero dispersion wavelength measurement through soliton self-frequency shift compensation in suspended core fibre
International audienceA simple experimental technique to evaluate the second zero dispersion wavelength of very small core microstrutured fibres is described. Based on the effect of soliton self-frequency shift and its subsequent compensation in the vicinity of the second zero dispersion. the proposed method is applied to both standard and suspended core microstructured fibres by simply measuring the frequency stabilised soliton spectrum, avoiding any calculation and knowledge of any experimental parameters
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