In the scope of miniaturized optical sensors for liquid refractometry, this work details the design, numerical simulation, and experimental characterization of a Fabry-Pérot resonator consisting of two deeply-etched silicon cylindrical mirrors with a micro-tube in between holding the liquid analyte under study. The curved surfaces of the tube and the cylindrical mirrors provide three-dimensional light confinement and enable achieving stability for the cavity illuminated by a Gaussian beam input. The resonant optofluidic cavity attains a high-quality factor (Q)-over 2800-which is necessary for a sensitive refractometer, not only by providing a sharp interference spectrum peak that enables accurate tracing of the peak wavelengths shifts, but also by providing steep side peaks, which enables detection of refractive index changes by power level variations when operating at a fixed wavelength. The latter method can achieve refractometry without the need for spectroscopy tools, provided certain criteria
Purpose: To compare lens dimensions and refractive index distributions in type 1 diabetes and age-matched control groups. Methods: There were 17 participants with type 1 diabetes, consisting of two subgroups (7 young [23 ± 4 years] and 10 older [54 ± 4 years] participants), with 23 controls (13 young, 24 ± 4 years; 10 older, 55 ± 4 years). For each participant, one eye was tested with relaxed accommodation. A 3T clinical magnetic resonance imaging scanner was used to image the eye, employing a multiple spin echo (MSE) sequence to determine lens dimensions and refractive index profiles along the equatorial and axial directions. Results: The diabetes group had significantly smaller lens equatorial diameters and larger lens axial thicknesses than the control group (diameter mean ± 95% confidence interval [CI]: diabetes group 8.65 ± 0.26 mm, control group 9.42 ± 0.18 mm; axial thickness: diabetes group 4.33 ± 0.30 mm, control group 3.80 ± 0.14 mm). These differences were also significant ...
Refractometry, a combination of physics, materials, and chemistry, is a measurement technique which determines the composition of known substances by means of calculating their respective refractive indexes (RI). RIs are evaluated via a refractometer, a device which measures the curve, or refraction, resulting when the wavelength of light moves from the air into and through a tested substance. The unitless number given by the refractometer, usually between 1.3000 and 1.7000, is the refractive index. The composition of the substance is then determined with a comparison of the measured RI to standard curves developed for the substance. There are four general types of refractometers: digital, analog, lab, and inline process. Although refractometry can measure a variety of substances, the most common group of known substances to calculate is liquids. Liquid based continuous processes benefit from the use of an inline process refractometer to provide real time data about process output or ...
In the course of the characterization of a NLO crystal the temperature dependence of the refractive indices is an important aspect: phase matching conditions e.g. for SHG can be adjusted effectively by changes of temperature. In this work two techniques for the measurement of the temperature dependence of refractive indices are presented, based on a Jamin interferometer and on the Rotating-Analyser method. Six borate crystals of different symmetry: Zn4[O(BO2)6] (PG: 43m), Li2B4O7 (PG: 4mm), beta-BaB2O4 (PG: 3m), PbB4O7 (PG: mm2), BiB3O6 (PG: 2) and Bi2ZnB2O7 (PG: mm2) were investigated in the temperature range 70-285 K. The influence of temperature change on phase matching is rather large for BiB3O6 while it is small for the other borates Li2B4O7, beta-BaB2O4 and Bi2ZnB2O7. Using the example of zinc guanidinium sulfate, Zn[C(NH2)3]2(SO4)2, the temperatur dependence of refractive indices, as well as of electro-optic and piezoelectric coefficients were studied with a special focus on the symmetry ...
Optical diffraction tomography relies on solving an inverse scattering problem governed by the wave equation. Classical reconstruction algorithms are based on linear approximations of the forward model (Born or Rytov), which limits their applicability to thin samples with low refractive-index contrasts. More recent works have shown the benefit of adopting nonlinear models. They account for multiple scattering and reflections, improving the quality of reconstruction. To reduce the complexity and memory requirements of these methods, we derive an explicit formula for the Jacobian matrix of the nonlinear Lippmann-Schwinger model which lends itself to an efficient evaluation of the gradient of the data-fidelity term. This allows us to deploy efficient methods to solve the corresponding inverse problem subject to sparsity constraints.. © 2017 Optical Society of America. Full Article , PDF Article ...
Optical diffraction tomography using a digital micromirror device for stable measurement of 4-D refractive index tomography of ...
Many materials have a well-characterized refractive index, but these indexes depend strongly upon the frequency of light. Standard refractive index measurements are taken at the "yellow doublet" sodium D line, with a wavelength of 589 nanometers. There are also weaker dependencies on temperature, pressure/stress, etc., as well on precise material compositions (presence of dopants, etc.); for many materials and typical conditions, however, these variations are at the percent level or less. Thus, it is especially important to cite the source for an index measurement if precision is required. In general, an index of refraction is a complex number with both a real and imaginary part, where the latter indicates the strength of absorption loss at a particular wavelength-thus, the imaginary part is sometimes called the extinction coefficient ...
We demonstrate large scale polarization contrast optical diffraction tomography (ODT). In cross-polarized sample arm detection configuration we determine, from the amplitude of the optical wavefield, a relative measure of the birefringence projection. In parallel-polarized sample arm detection configuration we image the conventional phase projection. For off-axis sample placement we observe for polarization contrast ODT, similar as for phase contrast ODT, a strongly reduced noise contribution. In the limit of small birefringence phase shift δ we demonstrate tomographic reconstruction of polarization contrast images into a full 3D image of an optically cleared zebrafish. The polarization contrast ODT reconstruction shows muscular zebrafish tissue, which cannot be visualized in conventional phase contrast ODT. Polarization contrast ODT images of the zebrafish show a much higher signal to noise ratio (SNR) than the corresponding phase contrast images, SNR=73 and SNR=15, respectively.. © 2020 ...
Purpose: Many labs use optical coherence tomography (OCT) to determine ocular parameters in the mouse eye when studying refractive development. The optical linear distance obtained with the OCT is converted to geometrical linear distance using the refractive index of the tissue. Since the optical power of the nocturnal mouse eye is largely dependent on the large ocular lens, many published studies have used the refractive index value of 1.433 for C57BL/6J mouse lenses reported by Remtulla and Hallett (Vision Res 25:21-31; 1985) using the Abbé refractometer. Calculations from the mouse paraxial schematic eye model suggest that refractive index increased from 1.568 to 1.605 between 22 and 100 days in C57BL/6J mice (Schmucker & Schaeffel, Vision Res 44:1857-67; 2004 ). The purpose of this study was to measure the refractive index of isolated mouse lenses across age and in different strains using OCT.. Methods: Lenses were carefully dissected from C57BL/6J wild-type (C57) and nob mice eyes at 4, ...
For many applications, there is a need to measure small changes in refractive index that are easily overwhelmed by nonspecific background signals. For example, measurements of concentration via refractive index require accurate temperature control, and refractive index based biosensors need to be made insensitive to non-specific binding or bulk refractive index changes. Differential measurements with two devices offer a partial remedy. However, the attainable background suppression is often limited due to alignment errors, fabrication tolerances, and other differences between independent sensors.. Diffractive optical microdevices open up a path to differential sensing with direct background cancellation by the interference of light waves. One key advantage of these devices is that the signal of interest and the reference are closely integrated and lie on the same beam path. This principle has previously been used for displacement sensing in micromechanics,11-13 for chemical sensing,14-17 and for ...
Surface plasmon resonance (SPR) based fiber optic sensor has been studied for multichannel and multianalyte sensing. Simulations have been carried out for a fiber optic sensor having two sensing regions coated with silver and gold for multichannel and multianalyte sensing. The simulated results have been obtained for different combinations of refractive indices of the samples around the probes. To support simulations optical fiber SPR probes with two sensing regions coated with silver and gold have been fabricated. SPR spectra for these sensors have been recorded for aqueous sucrose solutions of varying refractive indices. The refractive index of the liquid samples around both the gold and silver coated regions was kept the same to see the potential of SPR based fiber optic multichannel sensing, while it was kept different for studies related to multianalyte sensing. Both the theoretical and experimental results match qualitatively. The SPR resonance wavelengths for gold and silver being ...
Part physics, part material science and part chemistry, refractometry is the process which measures the composition of known substances by means of calculating their respective refractive indexes (RI). RIs are evaluated via a refractometer, a device which measures the curve, or refraction, resulting when the wavelength of light moves from the air into and through a tested substance. The unitless number given by the refractometer, usually between 1.3000 and 1.7000, is the RI. The composition of substances is then determined when the RI is compared to a standard curve specific to the material of the substance ...
JML-135-2007-105-114. This paper contains the results of a new experimental study of the effect of temperature on density, refractive index on mixing and ultrasonic velocity for a number of linear n-alkanes conbined with ethanol. A perusal of deviations between the experimental and calculated derived magnitudes shows that the predictive procedures give a qualitative estimation for the studied mixtures due to their high nonideality.. ...
A photonic nanojet (PNJ) corresponds to the specific highly localized spatial region of electromagnetic near-field distribution in the vicinity of a transparent micrometer-sized particle illuminated by a light wave. Here we consider dielectric spherical composite particles consisting of a core and several concentric shells having different refractive indices. The longitudinal and latitudinal sizes of a PNJ and its peak intensity depending on the optical contrast variation of shells are numerically investigated. We show that by properly changing the refractive indices of neighboring shells, it is possible to manipulate the PNJ shape and, in particular, extend its longitudinal size or increase its peak intensity.. © 2011 Optical Society of America. Full Article , PDF Article ...
An F.sub.2 -excimer laser has multiple closely-spaced spectral lines of interest around 157 nm, and one of the lines is selected by wavelength selection optics. The wavelength selection optics of a first preferred embodiment include a birefringent Brewster window enclosing the laser gas volume of the discharge chamber. The window preferably comprises MgF.sub.2 and is located at one end of the discharge chamber. One line is selected of the two when the optical thickness of the window is selected in coordination with rotatably adjustable, orthogonal refractive indices of the window. The transmissivity of the window is dependent on the orthogonal refractive indices and the optical thickness of the window. The wavelength selection optics of a second preferred embodiment include are at least partially within the laser active volume. In this way, line selection is performed in a manner which optimizes the combination of optical and discharge efficiency,
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Digital Hand-held "Pocket" Sodium bicarbonate Refractometer PAL-64S, ATAGO - 23-5584 23-5584-58 Digital Hand-held Pocket Sodium bicarbonate Refractometer PAL-64S ATAGO 4464 P-R, Refractometers, ATAGO Refractometers, Food Additives, Ingredient Refractometers, ATAGO Handheld pocket refractometer for chemical product ingredient measurement of sodium bicarbonate 0.0 to 10.0%, with a temperature range between 10.0 to 40.0 degrees C Automatic temperature compensation (ATC) for immediate and accurate calibration readings, regardless of ambient temperature LED-illuminated digital display, with an external light interference (ELI) feature to alert of outside light interference Rectangular palm-sized shape (109 x 55 x 31mm), with prism housed in circular sample well Durable, acrylonitrile butadiene styrene (ABS) resin body, with Ingress-Protection (IP)-65 rating for protection against dust and water jets
Date: Thu, 07 Jan 1999 14:26:03 -0600 From: Louis Bonham ,lkbonham at phoenix.net, Subject: Alcohol determination by refractometry [long] Hi folks: [Warning: hard-core beer geek information follows. ,g,] Many of us use a refractometer to assay the gravity of wort during the mash or before fermentation starts. Once fermentation begins, however, the alcohol in the wort/beer skews the reading because it has a different refractive index than water; i.e., it causes light to bend more than water. As a result, a beer that actually has a specific gravity of, say, 1.010 (as measured by a hydrometer, pycnometer, digital density meter, etc.) might read as 5.5 degrees Brix (SG 1.022) on a refractometer. Because of this significant discrepancy, the conventional wisdom has been that refractometers are useless once fermentation starts. (I plead guilty to being one of the parties promulgating this.) In fact, the difference between the actual specific gravity and the apparent gravity as measured by a ...
We present a novel methodology for optical fiber polymer microtip manufacturing ant testing, which supports the structure optimization process through utilization of an optical diffraction tomography system based on the lateral shear digital holographic microscope. The most important functional parameter of an optical fiber microtip is the output beam distribution in the far-field region, which depends on geometrical properties and refractive index distribution within the microtip. These factors, in turn, are determined by the optical power distribution of the actinic light and the exposition time during the photopolymerization process. In order to obtain a desired light field distribution we propose to govern the manufacturing process by a hybrid opto-numerical methodology, which constitutes a convenient feedback loop for modification of the fabrication parameters. A single cycle of the proposed scheme includes numerical modeling, tomographic measurements and modifications of fabrication ...
Solid para-H-2 is a promising gain medium for stimulated Raman scattering, due to its high number density and narrow Raman linewidth. In preparation for the design of a cw solid hydrogen Raman laser, we have made the first measurements, to our knowledge, of the index of refraction of a solid para-H-2 crystal, in the wavelength range of 430-1100 nm. For a crystal stabilized at 4.4 K, this refractive index is measured to be n(p-H2) 1.130 +/- 0.001 at 514 nm. A slight, but significant, dependence on the final crystal-growth temperature is observed, with higher n(p-H2) at higher crystal-growth temperatures. Once a crystal is grown, it can be heated up to 10 K with no change in n(p-H2). The refractive index varies only slightly over the observed wavelength range, and no significant birefringence was observed. (C) 2011 Optical Society of America. ...
Wholesale Ophthalmic Refractometer - Select 2018 high quality Wholesale Ophthalmic Refractometer products in best price from certified Chinese Digital Refractometer manufacturers, Portable Refractometer suppliers, wholesalers and factory on Made-in-China.com
Multilayer interference pigment consisting of plateletlike titanium dioxide as carrier material, coated with alternating layers of metal oxides of low and high refractive index, the difference in the refractive indices being at least 0.1, which is obtainable by solidification and hydrolysis of an aqueous solution of a thermally hydrolysable titanium compound on a continuous belt, detachment of the resulting coat, coating of the resulting titanium dioxide platelets, with or without drying in between, by a wet method with, alternately, a metal oxide hydrate of high refractive index and a metal oxide hydrate of low refractive index by hydrolysis of the corresponding, water-soluble metal compounds, separation, drying and, if desired, calcining of the material obtained.
This invention is directed to the preparation of silver halide-containing photochromic glasses exhibiting refractive indices between 1.585-1.610, Abbe numbers higher than 41, and densities less than 2.80 g/cm.sup.3 generally consisting essentially, in weight percent, of:
9 patients with monocular cataract aged 55-82 underwent surgery.The uncorrected visual acuity equaled 0.02-0.4.All patients underwent femto�â� � assisted phacoemulsification with the implantation of pseudo-accommodative IOL AcrySof ReSTOR (Alcon, USA) with �.0 D additional.The optical power of the IOL was calculated in emmetropic eye according to SRK/T formula.Femto laser stage was performed on a ZiemerFEMTO LDVZ8. Phacoemulsification was performed on StellarisPC Vision Enhancement system (Baush&Lomb,USA). The follow-up period was 6 months.The causes of loss of the paired eye were: phthisis bulbi, corneal leukoma, operated retinal detachment. Preoperative ophthalmological examination included visometry, tonometry, keratometry, refractometry, multiple biometrics,tomography of the retina ...
Urinary tract infections are the second infectious trouble which affects pets just after dermatologic affections. It is considered that 15% dogs and 1 to 3% cats have at least one urinary infection in their life time.. Two types of errors may be made in establishing the diagnosis: false positive animals diagnosed from clinical findings only and from a wrong interpretation of biological findings, and non identified infections due to the lack of systematic urinalysis.. Diagnostic steps. Urinalysis. Urinalysis is to be performed in order to analyze the physical, chemical, cytologic and microbiological features of urine. This includes several steps such as collecting urine, examining it, realizing a reagent strip, assessing urine specific gravity by refractometry, performing a nitric acid test to assess proteinuria, realizing urine sediment.. Use of urinalysis for the diagnosis of urinary tract infections Identification of organisms in urine is the only determining factor in the diagnosis of urinary ...
This study aimed to evaluate the digital Brix and optical serum total protein (STP) refractometers for measuring concentrations of serum immunoglobulin G (IgG) in alpacas and compare them to IgG concentrations measured by the reference method of radial immunodiffusion (RID) assay. The appropriate cutoff point for Brix and STP refractometers and the transmission infrared (TIR) spectroscopy method was determined for low IgG concentrations (, 10 g/L). Serum samples were collected from alpacas (N = Show moreThis study aimed to evaluate the digital Brix and optical serum total protein (STP) refractometers for measuring concentrations of serum immunoglobulin G (IgG) in alpacas and compare them to IgG concentrations measured by the reference method of radial immunodiffusion (RID) assay. The appropriate cutoff point for Brix and STP refractometers and the transmission infrared (TIR) spectroscopy method was determined for low IgG concentrations (, 10 g/L). Serum samples were collected from alpacas (N = ...
This study aimed to evaluate the digital Brix and optical serum total protein (STP) refractometers for measuring concentrations of serum immunoglobulin G (IgG) in alpacas and compare them to IgG concentrations measured by the reference method of radial immunodiffusion (RID) assay. The appropriate cutoff point for Brix and STP refractometers and the transmission infrared (TIR) spectroscopy method was determined for low IgG concentrations (, 10 g/L). Serum samples were collected from alpacas (N = Show moreThis study aimed to evaluate the digital Brix and optical serum total protein (STP) refractometers for measuring concentrations of serum immunoglobulin G (IgG) in alpacas and compare them to IgG concentrations measured by the reference method of radial immunodiffusion (RID) assay. The appropriate cutoff point for Brix and STP refractometers and the transmission infrared (TIR) spectroscopy method was determined for low IgG concentrations (, 10 g/L). Serum samples were collected from alpacas (N = ...
Anton Paar produces high precision measuring and laboratory instruments for industry and research. It is the world leader in the measurement of Density, Concentration and CO2 and in the field of Rheometry. Other areas of specialty are: Viscometry, Polarimetry, Refractometry, Microwave Sample Preparation & Synthesis, Surface Analysis and Characterisation, Nanostructure Analysis and X-Ray Scattering. Established in 1922, Anton Paar GmbH today is owned by the charitable Santner Foundation. Over 3200 employees at the headquarters in Graz and the sales subsidiaries worldwide ensure that Anton Paar products live up to their excellent reputation. The core competence of Anton Paar - high-precision production - and close contact to the scientific community form the basis for the quality of Anton Paars instruments. Located in St Albans, Anton Paar Limited provides sales, application support and service to users across the UK and ...
Elscolab offers an extensive range of instrumentation for industrial processes. There are dedicated solutions for every industry and all applications, ranging from food manufacturing via the pharmaceutical industry to heavy chemical processes.. Our equipment meets and exceeds todays industry standards. Of course they meet international guidelines and norms for safety (ATEX, SIL...) and hygiene (FDA, USP, EHEDG, …). The inline and online sensors are capable of digital and analogue communication with your process control system.. Our specialties: pH/ORP, oxygen, UV-VIS-NIR spectrophotometry, conductivity, colour, turbidity, refractometry, viscosity, pressure, temperature, flow, galvanic separators and much more.. ...
Merck provides a variety of Certipur® reference materials for special applications - from refractometry to TOC analysis to color measurement
MilliporeSigma provides a variety of Certipur® reference materials for special applications - from refractometry to TOC analysis to color measurement
Background Noninflammatory corneal ectasias is a group of diseases including keratoconus (KC), pellucid marginal degeneration (PMD), and keratoglobus. KC is the most common form of corneal ectasia characterized by progressive thinning of the central or inferior cornea, causing corneal steepening and cone formation. The disease typically presents during the second decade of life and is bilateral, but often one eye precedes the other. Detecting the cases of subclinical KC had always been a challenge for refractive surgeons especially when the suggestive clinical signs and symptoms to differentiate subclinical KC from the normal are not observed. Aim The aim of the study is to determine the prevalence of ectatic corneal conditions among keratorefractive population admitted for refractive surgery at Al-Mashreq Eye Centre, during the period from June 2017 till December 2017, using data from the Scheimpflug tomographer imaging system. Patients and methods Our study was conducted on patients seeking ...
Anton Paar develops, produces and distributes highly accurate laboratory instruments and process measuring systems, and provides custom-tailored automation and robotic solutions.. It is the world leader in the measurement of density, concentration and CO2 and in the field of Rheometry. Other areas of specialty are: Viscometry, Polarimetry, Refractometry, Microwave Sample Preparation & Synthesis, Chemical and Mechanical Surface and Nanostructure Analysis.. With over 2200 employees at the headquarters in Graz (Austria) and the 25 sales subsidiaries worldwide, Anton Paar ensure that their products live up to their excellent reputation. The core competence of the company - high-precision production - and close contact to the scientific community form the basis for the quality of Anton Paars instruments.. A strong sales network in more than 110 countries guarantees customers rapid support and answers to their application and service queries.. Innovation is the basis for progress and every year Anton ...
I found this text to be a well-written, practical guide to refractometry. An entire chapter of case studies really helps the reader apply the concepts learned. Dr. Kolkers book is a great text for new technicians, and a wonderful resource for technician trainers! ...
HT-2 microscope facilitates three-dimensional fluorescence and optical diffraction tomography of live cells with minimal stress on cells. 27 November 2018, Daejeon, South Korea: The HT-2 from Tomocube is the worlds first microscope to combine both holotomography and 3D fluorescence imaging into one unit. Capable of simultaneously capturing high resolution 3D optical diffraction tomography and 3D fluorescence images, the new microscope enables long-term tracking of specific targets in live cells while minimising stress. The capability to easily deliver holotomography and fluorescence correlative analysis in 2D, 3D and 4D will enable researchers and clinicians to open new frontiers in bioscience and better understand, diagnose, and treat disease.. "Research and diagnosis in the life sciences depends on the information that can be found using cellular analysis," says Aubrey Lambert, Tomocubes Chief Marketing Officer. "Current microscopy techniques limit the quantity and quality of information ...
Breeders Choice Equine Refractometer for Checking Colostrum [refract] - This refractometer is for measuring the quality of mares colostrum. Simply use the dropper to take a sample of colostrum post foaling and put it on the prism. Then hold the refractometer up to the light and look through the eyepiece. Measures Brix: 0-32% and Specific Gravity:1.000-1.120 Includes:One Refractometer, carry case, screw driver, sample dropper
1) M. P. Lisitsa et al.. Dispersion of the refractive indices and birefringence of CdSxSe1-x single crystals, Phys. Status Solidi, 31, 389-399 (1969) ...
The composition, particle shape, number concentration, size distribution, and spatial and temporal distributions of dust aerosols cause significant uncertainties in relevant radiative transfer simulations. The spherical particle approximation has been generally recognized to introduce errors in radiative transfer calculations involving dust aerosols. Although previous studies have attempted to quantify the effect of non-spherical particles, no consensus has been reached as to the significance of the dust aerosols non-spherical effect on flux calculations. For this study, we utilize a newly developed ultra-violet-to-far-infrared spectral database of the single-scattering properties of tri-axial ellipsoidal, mineral dust-like aerosols to study the non-spherical effect on radiative forcing. The radiance and flux differences between the spherical and ellipsoidal models are obtained for various refractive indices and particle size distributions. The errors originating from using the spherical model ...
Organic aerosols (OAs) in the atmosphere affect Earths energy budget by not only scattering but also absorbing solar radiation due to the presence of the so-called "brown carbon" (BrC) component. However, the absorptivities of OAs are not represented or are poorly represented in current climate and chemical transport models. In this study, we provide a method to constrain the BrC absorptivity at the emission inventory level using recent laboratory and field observations. We review available measurements of the light-absorbing primary OA (POA), and quantify the wavelength-dependent imaginary refractive indices (k OA, the fundamental optical parameter determining the particles absorptivity) and their uncertainties for the bulk POA emitted from biomass/biofuel, lignite, propane, and oil combustion sources. In particular, we parametrize the k OA of biomass/biofuel combustion sources as a function of the black carbon (BC)-to-OA ratio, indicating that the absorptive properties of POA depend strongly ...
Refractive index (RI) and its dispersion play a major role in interaction of electromagnetic wave with matter. Quantitative phase imaging (QPI) has proven to be a useful tool to estimate the RI from the sample-induced phase delay measurement at high spatio-temporal resolution. Here, we introduce near-infrared dispersive quantitative phase imaging (NIRD-QPI) of microscopic objects. The setup uses a new geometry for quantitative phase microscopy by use of spatial frequency filtering in Fourier plane. High resolution refractive index spectroscopic measurement over a range from 690 to 840nm in interval of 25nm is reported. This method could prove to be very useful for characterizing wide range of nano and biomaterials ...
0026]In general, for purposes of light reflection, coating thickness and refractive index are related, as seen from the above equations. A primary purpose of the coatings of the present technology is to reduce reflections from off axis light while minimizing any adverse effects on the transmission of off axis light and on the transmission of axial light. Accordingly, for a range of refractive indices, a range of coating thicknesses may be established that achieve this purpose using equations (A1) and (A2). Referring to the graph of FIG. 6, the curves represent the variation of reflectance of axial (on axis) light and off axis light with coating thickness for an exemplary embodiment of a coating that includes two coating layers of equal thickness. The x-axis of the graph represents the thickness of the coating layers, which are identical, not the total coating thickness. (The total coating thickness would be twice the coating layer thickness, in this case.) In the zone marked "A," the reflectance ...
Light changes speed as it moves from one medium to another (for example, from air into the glass of the prism). This speed change causes the light to be refracted and to enter the new medium at a different angle (Huygens principle). The degree of bending of the lights path depends on the angle that the incident beam of light makes with the surface, and on the ratio between the refractive indices of the two media (Snells law). The refractive index of many materials (such as glass) varies with the wavelength or color of the light used, a phenomenon known as dispersion. This causes light of different colors to be refracted differently and to leave the prism at different angles, creating an effect similar to a rainbow. This can be used to separate a beam of white light into its constituent spectrum of colors. A similar separation happens with iridescent materials, such as a soap bubble. Prisms will generally disperse light over a much larger frequency bandwidth than diffraction gratings, making ...
The two independent refractive indices of anisotropic crystals are quantified in terms of their birefringence, a measure of the difference in refractive index.
The present invention provides improved elastomeric interference films which are readily coextruded, have improved transparency, and have greater mismatches of refractive indices than those of the prior art. An improved elastomeric optical interference film comprising at least 100 alternating layers of at least first and second divergent substantially transparent elastomeric polymeric materials is provided. Adjacent layers of the first and second polymeric materials differ from each other in refractive index by at least about 0.05, and the thickness of the layers is from about 0.05 to about 0.5 micrometers. Stretching the films results in different wavelengths of light being reflected.
between two media (say air and water), then light is refracted (jargon for "bent") so that if the angle that the incoming ray makes with the interface is ui , then the outgoing ray comes out at an angle [4] ur = sin-1((n1/n2)sin(ui)), where n1 and n2 are properties of the two media in question called the refractive index of the material (again it is just a name, I could have called the property Karthik or Pradeep, but for the sake of conformity I call it by the name already given to it). Dont worry about the formula if it looks complicated to you. Think of it as follows. If someone told you that they shined light at the interface of two media of given refractive indices, you can just tap some keys on your calculator and know where to put your eye or your camera so that you can see the refracted ray. So much for that. But how does this explain dispersion? The key is that the properties n1 and n2 depend not only on what the medium in question is (i.e., water, air glass etc) but also on the color ...
Densities, viscosities, refractive indices and ultrasonic velocities of the binary mixtures of Acetophenone with Propyl acetate were measured over the entire mole fractions at (303.15, 313.15 and 323.15) K. From these experimental results, excess molar volumes VE, viscosity deviation ∆η, refractive index deviation ∆nD, deviations in isentropic compressibility ∆Ks and excess intermolecular free length ∆Lf are calculated. The viscosity values were fitted to the models of Krishnan- Laddha and McAllister. The thermo physical properties under study were fit to the Jouyban - Acree model. The excess values were correlated using Redlich-Kister polynomial equation to obtain their coefficients and standard deviations. It was found that in all cases, the data obtained fitted with the values correlated by the corresponding models very well. The results are interpreted in terms of molecular interactions occurring in the solution.
Refractive index increment dn/dc values when you need them? In light Equation displaying K=2 pi^2 n^2/lambda^4 / Since the refractive index is intuitively related to the density / specific volume of Starch, Aqueous Buffer, DNA = desoxyribonucleic acid ; RNA = ribonucleic acid ; SDS = sodium. measuring the refractive index which has the added advantage of requiring as little as 20 μl of sample. There is a simple linear relationship between refractive index and the density. (e.g. sucrose and NaCl). values for iodixanol solutions ) to get an absorbance . SDS-polyacrylamide and agarose gel electrophoresis. A Brix degree is a measure of the density or concentration of sugar solutions. There are two Relationship of Brix Tolerance to Refractive Index Tolerance. ...
Autori: Mihaela Antonina Cãlin, Marian Romeo Cãlin, Constantin Munteanu. Editorial: THE EUROPEAN PHYSICAL JOURNAL PLUS, 129:116, 2014.. Rezumat:. In this paper we propose a new approach to using reflectance spectrometry in connection with the Kramers-Kronig analysis for the determination of the complex refractive index of biological cells. Applying this procedure, the real and imaginary parts of the refractive index (refractive index and extinction coefficient) can be simultaneously determined. The accuracy of this procedure in the determination of the refractive index and extinction coefficient of culture media proved to be comparable with spectroscopic ellipsometry. Applying this procedure on the human umbilical vein endothelial cells (HUVEC), the results obtained from time-series measurements showed significant changes in the complex refractive index of cell cultures within 72h, the most important increases for both real and imaginary parts of the refractive index being recorded in the ...
Article Research on an Approach to Ultrasound Diffraction Tomography Based on Wave Theory in Sensors and Transducers Journal, Vol. 159, Issue 11, November 2013, pp.464-469
A retroreflective article that has a layer of optical elements and a multilayer reflective coating disposed on the optical elements. The reflective coating reflects light back into the optical elements so that it can be returned toward the light source. The multilayer reflective coating has multiple polymer layers and has layers that possess different refractive indices.