Search results for "Refractive"
showing 10 items of 559 documents
Conjunctival Sac Fluid Contains Elevated Levels of Soluble TRAIL: Implications for the Anti-Tumoral Surveillance of the Anterior Surface of the Eye
2008
Little is known on the ability of different epithelia to release soluble TNF-related apoptosis-inducing ligand (TRAIL) and the relevance of TRAIL secretion by epithelial cells is still incompletely understood. On these bases, we have measured the concentration of soluble TRAIL by ELISA in the conjunctival sac fluid. It was the highest ever detected in a biological fluid (mean value of 26,800 pg/ml), being approximately 20-fold greater than that found in human saliva and >200-fold greater than that detected in human serum. On the other hand, osteoprotegerin, the soluble decoy receptor of TRAIL, was almost undetectable in the conjunctival sac fluid. Of note, the levels of soluble TRAIL measur…
An experimental investigation of the nonlinear refractive index (n2) of carbon disulfide and toluene by spectral shearing interferometry and z-scan t…
2003
International audience; The recently proposed spectral shear interferometry and the well-known z-scan techniques were employed for the determination of the nonlinear refractive index n2 of CS2, toluene and fused silica. The determined n2 values by both techniques were found to be in very good agreement. In addition, the role of the repetition rate of the laser is also investigated revealing its importance for the correct determination of both the size and the sign of the nonlinearity.
Diffusiosmessungen an polymeren in lösung mittels tracer-technik
2007
A cell for measuring coefficients of diffusion and self-diffusion by tracer techniques is described. The cell consists of two Teflon disks and is of the rotational shearing type. The amount of polymer is minimal (about 0.1 ml. for both components). Labeled and unlabeled fractionated polymethacrylate of identical molecular weight distribution was used to determine diffusion coefficients in benzene and toluene. The classical optical measurement is impossible, for these solvents exhibit a refraction index very close to that of polymethacrylate. In acetone, where optical as well as tracer techniques are applicable, the measured diffusion coefficients of the two methods are in good agreement. Al…
Sputtered SiOxNy thin films: improving optical efficiency of liquid crystal diffuser elements in multi-focal near-to-eye display architecture
2021
In this work we present reactive sputtered SiOxNy films with a variable refractive index as a convienent solution for contrast improvement of liquid crystal diffuser multi stacks in near-to-eye AR/VR displays. The focus concerns minimization of light reflections between internal structures, in particular ITO, by optimizing internal layers through tailored properties of thin film coatings, as well as subsequent laser patterning of thin film stack. Inorganic thin films have been deposited on glass by physical vapor deposition. Corresponding refractive index, thickness, uniformity and dielectric characteristics and other electro-optical properties have been measured and their impact on the res…
Measurement technique for real-time and low-cost biosensing using photonic bandgap structures
2011
We present a sensing technique based on using photonic bandgap structures where only the output power is monitored, without the need of tunable sources or spectrum analyzers, thus providing a real-time and low-cost system.
<title>High-frequency electrodeless light sources for application</title>
2001
The high-frequency electrodes light sources (HFELS) are widely used as bright radiators of narrow and intensive spectral lines covering spectral region from VUV to IR. In this work we shall give a short overview of our experience in preparation of HFELS, containing He, H, Rb, Hg, Zn, Pb, As, Sb, Bi, Tl, Hg-Cd, Hg-Zn, Hg-Cd-Zn, Se-Te for different applications. Special attention would be paid for HFELS use in Zeeman mercury analyzer, in Atomic absorption analyzer and Angle and glass refractive index measurement system.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
New Analytical Tools for Evaluation of Spherical Aberration in Optical Microscopy
2010
The required tightly focused spots in three-dimensional (3D) scanning optical techniques are usually achieved by high-NA immersion lenses. The refractive index mismatch between the sample and the immersion medium introduces an important amount of spherical aberration when imaging deep inside the specimen, spreading out the focusing response. Since this aberration depends on the focalization depth, it is not possible to simultaneously achieve a global compensation for the whole scanned sample. In this way, the design of pupil elements that increase the tolerance to this aberration is of great interest. We present a new formalism for the evaluation and the design of filters that decrease the …
Near‐field optical addressing of single molecules in coplanar geometry: a theoretical study
2001
Photonic transfer through elongated optical structures of submicrometre section microfabricated at the surface of dielectric or semiconductor samples can be enhanced by an appropriate structuring of the local refraction index. We show from computerized simulations that both the light localization and the spectroscopic properties of such structures can be used to selectively excite, in coplanar geometry, individuals molecules located in the near-field.
A proposed equation of correlation for the study of thermodynamic properties (density, viscosity, surface tension and refractive index) of liquid bin…
2009
Abstract The literature on the physicochemical properties of liquid binary mixtures shows that most such systems exhibit nonlinear behavior. As a result, rigorous data and equations capable of affording a reliable estimate of the behavior of such mixtures are needed. The present study offers an equation of correlation providing a reliable estimation of the properties (density, viscosity, surface tension and refractive index) of binary mixtures of liquids as a function of mole fraction. In order to assess the validity of the proposed equation, the latter has been applied to reference binary mixtures, and comparisons have been made of the experimental values of the studied magnitudes versus t…
Volumetric properties, viscosities and refractive indices of binary liquid mixtures of tetrafluoroborate-based ionic liquids with methanol at several…
2015
Abstract Densities, speeds of sound, viscosities and refractive indices of two binary systems 1-butyl-3-methylimidazolium tetrafluoroborate [bmim][BF4] + methanol and 1-ethyl-3-methylimidazolium tetrafluoroborate [emim][BF4] + methanol, as well as of all pure components, have been measured covering the whole range of compositions at T = (278.15 to 318.15) K and p = 101 kPa. From this data, excess molar volumes, excess isentropic compressibilities, viscosity deviations and refractive index deviations were calculated and fitted to extended versions of the Redlich–Kister equation. Estimated coefficients of these equations taking into account the dependence on composition and temperature simult…