Search results for "Refractive index"
showing 10 items of 332 documents
Saharan dust absorption and refractive index from aircraft-based observations during SAMUM 2006
2009
During the Saharan Mineral Dust Experiment (SAMUM) conducted in summer 2006 in southeast Morocco, the complex refractive index of desert dust was determined from airborne measurements of particle size distributions and aerosol absorption coefficients at three different wavelengths in the blue (467 nm), green (530 nm) and red (660 nm) spectral regions. The vertical structure of the dust layers was analysed by an airborne high spectral resolution lidar (HSRL). The origin of the investigated dust layers was estimated from trajectory analyses, combined with Meteosat 2nd Generation (MSG) scenes and wind field data analyses. The real part n of the dust refractive index was found almost constant w…
Er:Cr:YSGG laser with electrooptic PLZT ceramics Q-switching Fabry-Perot interferometer output mirror
2001
Summary form only given. Q-switching of Er:Cr:YSGG laser with transparent PLZT ceramics electro-optic modulators was reported previously. The extremely large quadratic EO effect in PLZT allows to build small size moderate control voltages. The high induced birefringence in PLZT results from an essential contribution to polarization (and consequently to the birefringence) of processes with longer relaxation times up to seconds, corresponding to the Er:Cr:YSGG laser operating rate. PLZT ceramics have also a high value of the refractive index (n /spl ap/ 2.2-2.3 for /spl lambda/ = 3 /spl mu/m, slightly depending on PLZT composition and temperature) and thus considerable Fresnel reflections R/s…
Dyakonov-like surface waves in semi-infinite metal-dielectric lattices
2012
We demonstrated the existence of Dyakonov-like surface waves propagating at the boundary between a metal-insulator lattice and an isotropic dielectric. A range of propagation angles substantially greater than that for conventional birefringent materials is obtained, and with reasonably small losses.
Laser-induced anisotropy in terbium-gallium garnet
1998
Ga5O12 crystal when illuminated at the terbium ion resonance, becomes optically uniaxial. The optical axis is found to be along the beam-propagation axis. The origin of this symmetry breakdown is a thermal effect. Our observation of a conoscopic pattern is accounted for by a quadratic stress and refractive index distribution model. By spatial integration of the conoscopic pattern, the laser-induced stress birefringence variation as a function of the incident beam power is determined.
Dielectric polarization and polarizability of 1-pentanol+n-octane mixtures from static dielectric constant and refractive index data at 0,25 and 45�C
1990
Static dielectric constants and refractive indices of 1-pentanol+n-octane mixtures were measured in the temperature range between 0 and 45°C. Data discussed in terms of Kirkwood correlation factor and Lorentz-Lorenz molar refractivity give information on the short range intermolecular interactions between the components. The role played by the nonpolar n-octane in the destruction of 1-pentanol oligomers is also pointed out.
Influence of hydrogen-ion concentration on refractive index value in red blood cells of diabetes patients
2002
Since hyperglycaemia changes fluidity of erythrocyte cell membrane and impair cell deformability, our goal was to characterize light refractive properties of haemoglobin and red blood cells (RBC) in diabetes patients. Microscopic investigation was carried out on intact and in methanol fixed RBCs of diabetes patients with long-term hyperglycaemia (glycosylated haemoglobin > 7,5%). Interference microscopy was used for refractive index (RI) measurements at 18 different pH levels in range of 2 - 13. Results showed that the curves of RI in intact and fixed cells of diabetes patients and fixed cells for control group were of similar configuration, with one branch in alkaline portion, one branch i…
Thermo‐optical investigations of NaNbO 3 thin films by spectral ellipsometry
2009
In this work a spectroscopic ellipsometry was applied to the thermo-optical investigations of sodium niobate NaNbO3 (NN) thin films at the wide temperature range of 5–820 K. The temperature dependence of complex refractive index dispersions and optical bang energy of the direct allowed electron transitions were evaluated. Additionally dynamic scans of the main ellipsometric angles at the several fixed wave lengths of 300, 400, 500 and 635 nm were performed to acquire more detailed temperature dependences of the refractive index and extinction coefficient. Pronounced minima/maxima and substantial jumps in the temperature dependence of complex refractive index and band gap energy were found a…
Anisotropy of the refractive index and absorption coefficient in the layer plane of gallium telluride single crystals
1995
Refractive index and absorption coefficient of GaTe for light polarized in the optical axis directions in the layer plane are determined from transmission measurements. The refractive index is determined in the wavelength range from 0.7 to 25 μm and the absorption coefficient in the range of energies from 1.6 to 2 eV at room temperature and at 30 K. The optical constants are found to be anisotropic in the layer plane. The refractive index dispersion is interpreted through a Phillips-Van Vechten model and the Penn gaps for each direction are found to be E pg (⊥b) = 3.37 eV and E pg (∥b) = 3.58 eV. In the long-wavelength region a polar phonon contribution is also taken into account. The absor…
New aspects of scattering and absorbing properties of atmospheric aerosol particles
1972
Abstract Knowledge of the scattering and absorbing processes of the atmospheric aerosol particles in the solar wavelength range is necessary in order to calculate the energy balance of the atmosphere. Both of these depend on the relative humidity of the air. Until now little was known of the behavior of the particles. This paper shows experimental and theoretical results of the real and imaginary part of the refractive index of the aerosol particles at different relative humidities.
Densities, Viscosities, and Refractive Indices of Some Binary Liquid Systems of Methanol + Isomers of Hexanol at 298.15 K
1996
Viscosities, densities, and refractive indices of eight binary liquid systems containing ethanol + some isomers of hexanol have been determined at 298.15 K. The excess property values were fitted to the Redlich-Kister equation to estimate the binary coefficients and the standard deviations.