Search results for "Refractometry"
showing 10 items of 48 documents
Easy-use and low-cost fiber-based two-color dynamic light-scattering apparatus
2011
We present a small and compact two-color cross-correlation light-scattering setup designed to study the structure and dynamics of colloidal suspensions in the regime of considerable turbidity. Using a homemade concentric four-arm goniometer, combined with fiber-optical illumination and detection devices, allows an easy and long time stable alignment-even under a temperature variation of ∼5 °C. Tests with a nearly multiple scattering free suspension of small Rayleigh scatterers show intercepts in cross correlation near 0.4 over a wide range of scattering angles from 20° to 150°. Measuring slightly turbid samples in cross-correlation mode multiple scattering is sufficiently suppressed allowin…
Features of randomized electric-field assisted domain inversion in lithium tantalate
2011
We report on bulk and guided-wave second-harmonic generation via random Quasi-Phase-Matching in Lithium Tantalate. By acquiring the far-field profiles at several wavelengths, we extract statistical information on the distribution of the quadratic nonlinearity as well as its average period, both at the surface and in the bulk of the sample. By investigating the distribution in the two regions we demonstrate a non-invasive approach to the study of poling dynamics.
Photoalignment and Surface-Relief-Grating Formation are Efficiently Combined in Low-Molecular-Weight Halogen-Bonded Complexes
2012
It is demonstrated that halogen bonding can be used to construct low-molecular-weight supramolecular complexes with unique light-responsive properties. In particular, halogen bonding drives the formation of a photoresponsive liquid-crystalline complex between a non-mesogenic halogen bond-donor molecule incorporating an azo group, and a non-mesogenic alkoxystilbazole moiety, acting as a halogen bond-acceptor. Upon irradiation with polarized light, the complex exhibits a high degree of photoinduced anisotropy (order parameter of molecular alignment > 0.5). Moreover, efficient photoinduced surface-relief-grating (SRG) formation occurs upon irradiation with a light interference pattern, with…
Self-assembly of C60 fullerene molecules in the hexane–xylene solvent system
2021
The behavior of self-assembly of C60 molecules in solutions of C60/hexane/xylene were studied by the methods of refractometry, ultraviolet–visible spectroscopy and dynamic light scattering (DLS). I...
Equivalences between refractive index and equilibrium water content of conventional and silicone hydrogel soft contact lenses from automated and manu…
2007
PURPOSE: The purpose of the present study was to develop mathematical relationships that allow obtaining equilibrium water content and refractive index of conventional and silicone hydrogel soft contact lenses from refractive index measures obtained with automated refractometry or equilibrium water content measures derived from manual refractometry, respectively. METHODS: Twelve HEMA-based hydrogels of different hydration and four siloxane-based polymers were assayed. A manual refractometer and a digital refractometer were used. Polynomial models obtained from the sucrose curves of equilibrium water content against refractive index and vice-versa were used either considering the whole range…
Thermo-optic control of dielectric-loaded plasmonic waveguide components
2010
International audience; We report preliminary results on the development of compact (length 20%) is demonstrated with MZI-and WRR-based components, and efficient (similar to 30%) rerouting is achieved with DC switches. (C) 2010 Optical Society of America
Direct optical measurement of light coupling into planar waveguide by plasmonic nanoparticles
2012
Coupling of light into a thin layer of high refractive index material by plasmonic nanoparticles has been widely studied for application in photovoltaic devices, such as thin-film solar cells. In numerous studies this coupling has been investigated through measurement of e.g. quantum efficiency or photocurrent enhancement. Here we present a direct optical measurement of light coupling into a waveguide by plasmonic nanoparticles. We investigate the coupling efficiency into the guided modes within the waveguide by illuminating the surface of a sample, consisting of a glass slide coated with a high refractive index planar waveguide and plasmonic nanoparticles, while directly measuring the inte…
Self-phase modulation-based 2R regenerator including pulse compression and offset filtering for 42.6 Gbit/s RZ-33% transmission systems
2009
International audience; We report on the experimental and theoretical study of a self-phase-modulation-based regenerator at 42.6 Gbit/s with a return-to-zero 33% format. We point out some detrimental effects such as intrachannel interactions and Brillouin scattering. An efficient solution, relying on a self-phase-modulation-based pulse compressor in combination with the regenerator, is proposed to overcome these detrimental phenomena. The experimental demonstration shows the effectiveness of a wavelength-transparent regenerator at 42.6 Gbit/s with a sensitivity-improvement of more than 5 dB and an eye-opening improvement of 2.3 dB in a back-to-back configuration, as well as a 10 times maxim…
Soft proton exchanged channel waveguides in congruent lithium tantalate for frequency doubling
2010
We report on stable optical waveguides fabricated by soft-proton exchange in periodically-poled congruent lithium tantalate in the a-phase. The channel waveguides are characterized in the telecom wavelength range in terms of both linear properties and frequency doubling. The measurements yield a nonlinear coefficient of about 9.5pm/V, demonstrating that the nonlinear optical properties of lithium tantalate are left nearly unaltered by the process. (C) 2010 Optical Society of America
Planar metamaterial analogue of electromagnetically induced transparency for plasmonic sensing.
2009
We experimentally demonstrate a planar metamaterial analogue of electromagnetically induced transparency at optical frequencies. The structure consists of an optically bright dipole antenna and an optically dark quadrupole antenna, which are cut-out structures in a thin gold film. A pronounced coupling-induced reflectance peak is observed within a broad resonance spectrum. A metamaterial sensor based on these coupling effects is experimentally demonstrated and yields a sensitivity of 588 nm/RIU and a figure of merit of 3.8.