Measurement Of Optical Parameters Research Articles

Simultaneous measurement of thickness and group refractive index in birefringent crystals

In order to measure the group refractive index and thickness of birefringent crystals simultaneously, a method based on spectral-domain interferometry is proposed. The optical path of each reflection layer of birefringent crystal is converted into spectral interference fringe of corresponding frequency by the principle of spectral-domain interferometry, and the accurate optical path calculation is realized by fast Fourier transform and Hanning-windowed energy centrobaric method. A two-step measurement method was designed to measure the crystal thickness and group refractive index of ordinary ( o ) and extraordinary ( e ) light synchronously by comparing the changes of the optical path before and after the insertion of the sample. The comparison between experimental and theoretical results of LiNbO3 crystals shows that the accuracy of the thickness measured by this system is better than 1 μm and the relative error of the group refractive index is better than 0.15%. The measurement method is simple to implement and has high precision, which is of practical significance for realizing the rapid and high-precision measurement of optical parameters of birefringent crystals.

Characterization of Core–Shell CaFe1.925Sm0.05Gd0.025O4 @ Polymer from Synthesis to Applications

A novel core/shell nanoferrite material has been developed for use in various potential applications. Rare-earth doped calcium-ferrite with the compositional formula CaFe1.925Sm0.05Gd0.025O4\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ ext{Ca}{\ ext{Fe}}_{1.925}{\ ext{Sm}}_{0.05}{\ ext{Gd}}_{0.025}{\ ext O}_4$$\\end{document} was prepared as a core using the citrate auto-combustion method before being coated with PVA as a polymeric shell. High crystalline and single-phase orthorhombic nanoparticles are confirmed by XR-D (X-ray diffraction). An estimate has been made for the mean size of the crystal structures by analyzing the broadening of XR-D lines within a range of 20 nanometers. HR-TEM (high-resolution tunnelling electron microscope) micrographs also showed that the particles had an orthorhombic shape with well-defined boundaries. EDX (energy-dispersive X-ray) and FT-IR were used to investigate the elemental constitution and the molecular structure of samples. The dielectric properties were discussed in the basics of interfacial polarization and Koop`s model. The anti-ferromagnetic nature of the samples was identified by a VSM (vibrating sample magnetometer). The proposed composition was found to improve the electromagnetic absorption performance, which was confirmed with the measurements of optical parameters from the absorbance spectrum recorded by the UV–VIS–NIR spectroscope. The optical band-gap and Urbach energies of the synthesized samples have been investigated, in addition to the refractive index and the extinction coefficient. The Wemple-DiDomenico oscillator model was used to examine the dispersion energies.

Influence of immersion agents on optical parameters of bio-tissues during laser photothermal therapy of tumor: pilot study

Combined use of an immersion agent with low-intensity laser irradiation for optical clearing of skin before plasmon photothermal therapy (PPTT) procedure is offered. Pilot study results of influence of the immersion agents on optical parameters of skin, subdermal connective tissue and model tumor of rats in vivo at hyperthermia during PPTT are presented. Model of alveolar liver cancer --- cholangiocarcinoma, transplanted under the skin, was used as a model tumor. For PPTT the gold nanorods with absorption band in the area of diode laser radiation (808 nm) were introduced. Monitoring of light attenuation coefficient change in skin at optical clearing was performed using optical coherent tomography. Measurements of optical parameters of the complete tumor and its layers were performed using spectrometers in a wave length range of 350-2200 nm. Reduction of skin thermal damage during PPTT with preliminary optical clearing using immersion agent (mixture of 70% glycerol water solution and 10% DMSO) and low-intensity laser irradiation at wave length of 808 nm is observed. Keywords: gold nanorods, IR laser radiation, optical clearing, optical parameters, plasmon photothermal therapy.

Mathematical and computational modeling for the determination of optical parameters of breast cancer cell

ABSTRACT This study enumerates the quantitative measurement of optical parameters used in several diagnostic procedures for malignant tissue. Optical diagnosis is proposed due to its non-invasive and non-destructive nature. This paper recapitulates Fresnel equation (polarization independent) to determine the characteristic critical angle of malignant tissue. The critical angle of malignant tissue is lower than healthier tissue and is therefore an optical parameter of interest for lesion tissue diagnosis. Similarly, a quantitative analysis is derived to commensurate refractive index and absorption and reflective property of tissue and its nuance with healthier counterparts. The second dichotomy of the research concentrates on comparing and validating the mathematical analysis with COMSOL Multiphysics® 5.2 simulation. The magnitude of malignant tissue reflectance is obtained across a range of incident angle ranging from 0° to 90°. The simulation results satiate the quantitative analysis with only 1.3% deviation. This quantitative result provides prospect of collaborating bio-electromagnetism results with Artificial Intelligence technology for active disease progression diagnosis utilizing minimum invasive diagnostic procedure.

Measurement of the optical constants of monolayer MoS2 via the photonic spin Hall effect

How to explore the physical effect and characterize physical parameters in atomic scale crystals is still a challenging issue in modern optics. We detect the photonic spin Hall effect in monolayer MoS2 to study the atomic light-matter interaction. Due to the sensitive dependence of the spin-Hall shifts on the optical constants of MoS2, we propose this fundamental effect as a metrological tool for the parameter characterization. Combined with the weak-value technique, the experimental results show that the complex refractive index can be extracted by treating the atomically thin MoS2 as a homogeneous slab with an effective thickness. However, modeling the thin crystal as a surface current can determine the optical conductivity with a high measurement resolution. We believe this fast and precise measurement of optical parameters can provide a reliable approach to investigate optical properties for transition metal dichalcogenides.

单波长椭偏法测量各向异性晶体光学参数的研究

单波长椭偏法测量各向异性晶体光学参数的研究

Measurement of Optical Parameters and Electrical Conductivity for Determining the Quality of Besuki Local Honey Using Spectrophotometer

Honey is one of the foods that have been found in the world, consisting of natural sweet liquids, derived from flowers collected by honey bees. Honey is made from a mixture of complex, airborne, and most minor components that can be susceptible to counterfeiting. The components of honey can also be used by excessive storage for the manufacturing process or with inadequate storage. Determining the quality of honey is an important factor for producers. This study determines the quality of local honey based on optical parameter values. Determination of honey quality is based on optical parameters using a spectrophotometer to measure absorbance. From this absorbance it is used to determine: color at 560 nm, diastase number at 620 nm, sugar content at 500 nm, fructose content at 518 nm, invertase at 400 nm, and HMF at 284nm. All measurements were carried out using a spectrophotometer. The results of this measurement then compare the European (EC) and Indonesian quality (SNI) quality regulations.

基于包-全法的红外滤光片光学参数测量方法

基于包-全法的红外滤光片光学参数测量方法

Optical parameters detection with multi-frequency modulation based on NIR DPDW

For measuring the optical parameters of biological tissues accurately and rapidly, this study built an optical parameters measurement system based on near-infrared (NIR) Diffuse Photon Density Waves (DPDW) technology using frequency sweep modulation. The transmitted swept optical amplitude and phase can be nonlinearly fitted according to the physical diffusive approximation equation then to obtain the absorption coefficient and reduced scattering coefficient of the tissue phantoms, respectively. The experimental results of the 20 Intralipid solutions show that the average absolute errors of μa and μs′ are 0.066 cm−1 and 0.716 cm−1, respectively, and the correlation coefficients between the measured and true values were 0.965 and 0.989, respectively. The experimental results of the 3 solid phantoms show that the average absolute errors of μa and μs′ are 0.1140 cm−1 and 0.0023 cm−1, respectively. Therefore, the DPDW technology with frequency sweep modulation can detect the optical parameters of the tissue phantoms accurately and quickly, and it would be optimized for tissue tomography imaging and blood components noninvasively detection in vivo.

Joint measurements of optical parameters by irradiance scintillation and angle-of-arrival fluctuations

AbstractA method for joint measuring the power law exponent and the structure constant of atmospheric turbulence is proposed and examined. The measurements are equivalent to solve the simultaneous equations formed by the irradiance scintillation index and the angle-of-arrival fluctuations variance, where the measured parameters are regarded as the unknowns. The measured error analysis is also presented. Based on our proposed method, the measured results accord with the daily trend of atmospheric turbulence.

Factors affecting measurement of optic parameters by time-resolved near-infrared spectroscopy in breast cancer.

The purpose of this study was to evaluate the effects of the thickness and depth of tumors on hemoglobin measurements in breast cancer by optical spectroscopy and to demonstrate tissue oxygen saturation (SO2) and reduced scattering coefficient (μs') in breast tissue and breast cancer in relation to the skin-to-chest wall distance. We examined 53 tumors from 44 patients. Total hemoglobin concentration (tHb), SO2, and μs' were measured by time-resolved spectroscopy (TRS). The skin-to-chest wall distance and the size and depth of tumors were measured by ultrasonography. There was a positive correlation between tHb and tumor thickness, and a negative correlation between tHb and tumor depth. SO2 in breast tissue decreased when the skin-to-chest wall distance decreased, and SO2 in tumors tended to be lower than in breast tissue. In breast tissue, there was a negative correlation between μs' and the skin-to-chest wall distance, and μs' in tumors was higher than in breast tissue. Measurement of tHb in breast cancer by TRS was influenced by tumor thickness and depth. Although SO2 seemed lower and μs' was higher in breast cancer than in breast tissue, the skin-to-chest wall distance may have affected the measurements.

Effect of annealing temperature on properties of molybdenum disulfide thin films

The technologically significant molybdenum disulfide thin films were coated onto a non-conducting glass substrates using Automatic-CBD process. Consequences of annealed process on its physical appearance of the thin films, thickness, morphology, growth, structural and optical properties of the films were studied. The annealed sample shows an impact on the structural analysis, lattice cell, volume, average crystallite parameters. The effects of annealed temperature on the XRD pattern show that the increase of crystallite size leads to decrease in the grain boundary which will decrease in the dislocation density. Optical parameters measurement revealed that the optical band energies values of the annealed thin films lie in the range among 1.78–2.08 eV for temperature range 373–473 K. The obtained values were confirmed by photoluminesce. Surface morphology study by FE-scanning electron microscopy showed increase of grain sizes with annealing temperature. The Effect of annealed temperature on properties of thin films is discussed from the point of applications based on achieving high-performance opto-electronics and solar devices.

具有在线形貌矫正能力的组织体光学参数测量系统

具有在线形貌矫正能力的组织体光学参数测量系统

THE CERTIFIED REFERENCE MATERIALS OF ORGANIZATION FOR OPTICAL PARAMETERS MEASUREMENT OF SINGLE CRYSTALS AND STOCKS ON THEIR BASE

The effectiveness of metrological control and consequently the credibility of test results directly depend on the level of certified reference material completeness in laboratory. In the sphere of single crystals optical parameters measurement the deficiency of state and manufactured certified reference materials takes place. Therefore, the development and application of certified reference materials of organization are reasonable and effective. The experience of development and application of organization certified reference materials designed for control of stability and guaranteeing of measurement traceability in the testing laboratory «Single crystals and stocks on their base» of National University of Science and Technology «MISIS» is considered.

The TUS orbital detector optical system and trigger simulation

The TUS orbital experiment is aimed to study energy spectrum, composition and arrival directions of the Ultra High Energy Cosmic Rays (UHECR) at E ~ 1020 eV. The TUS mission is planned for operation at the dedicated "Mikhail Lomonosov" satellite. The TUS detector will measure the fluorescence and Cherenkov light radiated by EAS of the UHECR using the optical system – Fresnel mirror-concentrator of 7 modules of ~2 m2 area in total. Status of the Fresnel mirror production, its optical parameters measurement and the TUS trigger system simulation are presented.

The TUS Fesnel mirror production and optical parameters measurement

The TUS space experiment is aimed to study energy spectrum, composition, and angular distribution of the Ultra-High Energy Cosmic Ray (UHECR) at E ∼ 1020 eV. The TUS mission is planned for operation at the end of 2012 at the dedicated “Mikhail Lomonosov” satellite. The TUS detector will measure the fluorescence and Cherenkov light radiated by EAS of the UHECR using the optical system—Fresnel mirror-concentrator of 7 modules of ∼2 m2 area in total. Production of the flight model of the optical system is in progress. Status of the Fresnel mirror production, the method, and results of their optical parameters measurement are presented.

A Simple Method to Minimize Orientation Effects in a Profiling Radiometer

Marine optical parameters required for ocean color satellite applications must be measured with high accuracy and errors within the permissible limits. These stringent requirements demand careful measurements of optical parameters. Though the free-fall radiometer is found to be a better option for measuring underwater light parameters as it avoids the effects of ship shadow and is easy to operate, the measurements demand profiling the radiometer vertical in water with minimum tilt. Here we present the results of our observations on the tilts of the radiometer from the measurements in the Arabian Sea. Since there is hardly any study carried-out on the tilt of the profiling radiometer, the result of this study will help in the better design of such marine instruments. The tilt of the radiometer near the surface of the water is attributed to the mode of deployment and environment parameters, while the tilt at depth of the water is influenced by the density variations of the water. Here we also demonstrate a method of deploying the instrument that minimizes the tilt of the instrument at the surface layer of the water.

Research on Non-Invasive Measurement of Optical Parameters of the Tissues by Support Vector Machine

To measure optical parameters of biological tissues, support vector machine was adopted. The diffuse reflected light on the surface of the biological tissue corresponding to optical characteristic parameters of human tissue were obtained by Monte Carlo simulation. The nonlinear relationship model had been established between the diffuse reflected light and the optical parameters. The optical parameters were obtained by the support vector machine and the diffuse reflected light. That were compared with the given values of the same sample, and they were coherent basically. It was shown that support vector machine used to measure optical parameters had a high accuracy.

Properties of Phase Functions for Biological Materials with Properties of Composite Materials and their High-Order Parameters

Biological materials with properties of composite materials are complex, phase function can describe the complexity. Several phase functions and their high-order parameters were discussed. The results demonstrate that: single HG(Henyey-Greenstein) phase function can not describe the scattering of real biological material, the high-order parameters are dependent on the first-order parameter; Mie phase function can provide theorical reference for scattering chart of biological material although the function is complex;Tissue phase function can picture scattering for most biological materials and the form is simpleness, the high-order parameters are independent and relate to the micro-structures of biological material. it is necessary of selecting appropriate phase function for applied technology of medical diagnosis and measurement of optical parameters.

Optical parameters measurement for diagnostic and photodynamic therapy of human cervical adenocarcinoma (HeLa) cell line

The purpose of this study was to investigate the optical properties, absorption coefficient (μ a ) scattering coefficient (μ s ) and refractive indices, (n) of HeLa cell line in a suspension of 2% minimum essential medium (MEM) at two different (632.8 and 532.0 nm) wave lengths of laser light. Optical properties were determined with Kubelka Munk Model (KMM) and refractive index measurement was made through minimum angle of deviation method (MAD). We reported μ a = 8.643 ± 0.187 and 2.348 ± 0.249 cm−1 and μ s = 5.609 ± 0.287 and 88.166 ± 2.833 cm−1 at 632.8 and 532.0 nm, respectively. Refractive index was found to be 1.332 and 1.312 at 632.8 nm and 532.0 nm, respectively. The discussed results provide a route of information for clinical diagnosis, therapeutic application and dosimetry studies in HeLa and other cell lines.