33A-1: 9a KH2PO4 [F]: 9a Optical properties: refractive indices, birefringence, reflection, absorption

2006 ◽  
pp. 1-40 ◽  
Author(s):  
E. Nakamura ◽  
M. Komukae ◽  
T. Osaka
Keyword(s):  
Optical Properties ◽  
Refractive Indices

scholarly journals Microstructure-Induced Anisotropic Optical Properties of YF3 Columnar Thin Films Prepared by Glancing Angle Deposition

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2413
Author(s):  
Yao Shan ◽  
Pian Liu ◽  
Yao Chen ◽  
Haotian Zhang ◽  
Huatian Tu ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Volume Fraction ◽  
Electron Beam Evaporation ◽  
Glancing Angle Deposition ◽  
Refractive Indices ◽  
Glancing Angle ◽  
Axis Parallel ◽  
Angle Deposition ◽  
Deposition Angle

Yttrium fluoride (YF3) columnar thin films (CTFs) were fabricated by electron beam evaporation with the glancing angle deposition method. The microstructures and optical properties of YF3 CTFs were studied systematically. The YF3 films grown at different deposition angles are all amorphous. As the deposition angle increases, the columns in YF3 CTFs become increasingly separated and inclined, and the volume fraction of YF3 decreases, resulting in lower refractive indices. This phenomenon is attributed to the self-shadowing effect and limited adatom diffusion. The YF3 CTFs are optically biaxial anisotropic with the long axis (c-axis) parallel to the columns, the short axis (b-axis) perpendicular to the columns, and the other axis (a-axis) parallel to the film interface. The principal refractive index along the b-axis for the 82°-deposited sample is approximately 1.233 at 550 nm. For the 78°-deposited sample, the differences of principal refractive indices between the c-axis and the b-axis and between the a-axis and the b-axis reach the maximum 0.056 and 0.029, respectively. The differences of principal refractive indices were affected by both the deposition angle and the volume fraction of YF3.

Optical properties of a liquid crystal with small ordinary and extraordinary refractive indices and small optical anisotropy

2014 ◽  
Vol 22 (3) ◽  
Author(s):  
J. Kędzierski ◽  
K. Garbat ◽  
Z. Raszewski ◽  
M. Kojdecki ◽  
K. Kowiorski ◽  
...  
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Liquid Crystal ◽  
Optical Anisotropy ◽  
Order Parameter ◽  
Orientational Order ◽  
Refractive Indices ◽  
Orientational Order Parameter ◽  
Unknown Density ◽  
Abbe Refractometer

AbstractOptical properties of a nematic liquid crystal with small refractive index and small birefringence were studied. The ordinary and extraordinary refractive indices and birefringence were measured as functions of temperature by using an Abbe refractometer and wedge nematic cells. From values of these indices the nematic orientational order parameter was calculated by using several methods and corresponding mathematical models. Kuczyński et al. method was found to be suitable for determining the order parameter also for materials featuring small ordinary refractive index, with unknown density.

scholarly journals MOPSMAP v0.9: A versatile tool for modeling of aerosol optical properties

2018 ◽  
Author(s):  
Josef Gasteiger ◽  
Matthias Wiegner
Keyword(s):  
Remote Sensing ◽  
Optical Properties ◽  
Aerosol Particles ◽  
Particle Orientation ◽  
Spherical Particles ◽  
Refractive Indices ◽  
Hygroscopic Growth ◽  
Web Interface ◽  
Optical Modeling ◽  
Wide Range

Abstract. The spatiotemporal distribution and characterization of aerosol particles are usually determined by remote sensing and optical in-situ measurements. These measurements are indirect with respect to microphysical properties and thus inversion techniques are required to determine the aerosol microphysics. Scattering theory provides the link between microphysical and optical properties; it is not only needed for such inversions but also for radiative budget calculations and climate modeling. However, optical modeling can be very time consuming, in particular if non-spherical particles or complex ensembles are involved. In this paper we present the MOPSMAP package (modeled optical properties of ensembles of aerosol particles) which is computationally fast for optical modeling even in case of complex aerosols. The package consists of a data set of pre-calculated optical properties of single aerosol particles, a Fortran program to calculate the properties of user-defined aerosol ensembles, and a user-friendly web interface for online calculations. Spheres, spheroids, and a small set of irregular particle shapes are considered over a wide range of sizes and refractive indices. MOPSMAP provides the fundamental optical properties assuming random particle orientation, including the scattering matrix for the selected wavelengths. Moreover, the output includes tables of frequently used properties such as the single scattering albedo, the asymmetry parameter or the lidar ratio. To demonstrate the wide range of possible MOPSMAP applications a selection of examples is presented, e.g., dealing with hygroscopic growth, mixtures of absorbing and non-absorbing particles, the relevance of the size equivalence in case of non-spherical particles, and the variability of volcanic ash microphysics. The web interface is designed to be intuitive for expert and non-expert users. To support users a large set of default settings is available, e.g., several wavelength-dependent refractive indices, climatologically representative size distributions, and a parameterization of hygroscopic growth. Calculations are possible for single wavelengths or user-defined sets (e.g., of specific remote sensing application). For expert users more options for the microphysics are available. Plots for immediate visualization of the results are shown. The complete output can be downloaded for further applications. All input parameters and results are stored in the user’s personal folder so that calculations can easily be reproduced. The MOPSMAP package is available on request for offline calculations, e.g., when large numbers of different runs for sensitivity studies shall be made.

Soot Optical Properties in the Terahertz Spectra Domain

2012 ◽  
Vol 134 (7) ◽  
Author(s):  
Fei Wang ◽  
Ting Xu ◽  
Zhishen Qiang ◽  
Qunxing Huang ◽  
Dong Liu ◽  
...  
Keyword(s):  
Optical Properties ◽  
Time Domain ◽  
Wavelength Region ◽  
Optical Methods ◽  
Optical Data ◽  
Refractive Indices ◽  
Spectroscopy Technique ◽  
Terahertz Time Domain Spectroscopy ◽  
Time Domain Spectroscopy ◽  
Combustion Diagnostics

For understanding and accurately modeling combustion, the important questions are what species are present in the flame, and the spatial distribution and temperature of these species. Traditional optical methods used only the electromagnetic waves in the wavelength region from the ultraviolet region up to the infrared. Terahertz time-domain spectroscopy technique can be used for the combustion research as a novel tool. However, for some sooty combustion environments, the strong absorption, spectral interference from soot scattering, and fluorescence from large molecules must be considered. The optical properties of soot in the terahertz domain are the main basic data for terahertz application. In this paper, the terahertz time-domain spectroscopy technique was used to study the optical properties of flame soot within 0.2–1.6 THz. The complex refractive indices of the soot were deduced by the fixed-point iteration method. In order to validate the results, the complex refractive indices of the soot from the four different fuel flames were deduced. It was found that the complex refractive indices in the terahertz domain of the soot from the different fuel flames are very close to each other. The comparisons of complex refractive indices between the visible–IR domain and the terahertz domain indicate that the value of absorption index in terahertz domain is smaller than in IR domain, which implies that the terahertz wave will penetrate the sooty flame with smaller absorption than the IR rays. The results can provide the basic optical data of flame soot for the application of terahertz time-domain spectroscopy technique in the optical combustion diagnostics and extend the optical combustion diagnostics application area.

Optical Properties of Nd Doped Lead Borotellurite Glass

2016 ◽  
Vol 846 ◽  
pp. 193-198 ◽  
Author(s):  
Azman Kasim ◽  
H. Azhan ◽  
S. Akmal Syamsyir ◽  
Mardhiah Abdullah ◽  
M.R.S. Nasuha
Keyword(s):  
Optical Properties ◽  
Room Temperature ◽  
Optical Band Gap ◽  
Band Gap Energy ◽  
Rare Earth Ions ◽  
Band Gaps ◽  
Refractive Indices ◽  
Excitation Wavelength ◽  
Gap Energy ◽  
Trivalent Rare Earth

Many trivalent rare earth ions such as Er3+, Tm3+, Ho3+, Pr3+ and Nd3+ were doped as absorption and emission centers in glass hosts. In this work, lead borotellurite (PBT) glass doped with neodymium ion (Nd3+) has been prepared and characterized by mean of their optical properties. The UV-Vis measurement has been carried out in order to determine the optical band gap energy, reflective indices and the polarizability. Optical absorption spectra of the glass samples are recorded in the range 400–900 nm at room temperature From the result, there are six significant absorption peaks that corresponds to 525 nm, 584 nm, 683 nm, 747 nm, 805 nm and 878 nm wavelength have been observed with the most predominant peak to be used as excitation wavelength is found centered at 584 nm. The energy band gaps as well as the refractive indices were found to vary from 2.50eV to 2.59eV and from 1.89 to 1.96 with mol% of Nd content respectively. Meanwhile, the polarizability shows a similar trend of results to refractive indices as it varies from 5.56 x 10-24 cm3 to 5.63 x 10-24 cm3. These results will be discussed further in details.

The use of a slit in determining refractive indices with the microscope

1917 ◽  
Vol 18 (84) ◽  
pp. 130-132
Author(s):  
John William Evans
Keyword(s):  
Crystal Structure ◽  
Refractive Index ◽  
Optical Properties ◽  
Critical Angle ◽  
Total Reflection ◽  
Index Of Refraction ◽  
Refractive Indices ◽  
Object Image ◽  
Ordinary Object

Certain optical properties of crystals, and more particularly the refractive index, may be determined either in the directions-image, often referred to as the 'image in convergent light', or in the ordinary object-image in which the object itself is seen. In the former case, in which the index of refraction is 'usually determined by means of the critical angle of total-reflection, every point in the image corresponds to a single direction of propagation of the wave-front through the crystal-structure and to the two corresponding directions of vibration. One of these can, however, be eliminated by the insertion of a nicol in an approximate position, and thus all ambiguity in the determination of the refractive index is removed.

Optical Properties of II-IV-N2 Semiconductors

2004 ◽  
Vol 831 ◽  
Author(s):  
John Muth ◽  
Ailing Cai ◽  
Andrei Osinsky ◽  
Henry Everitt ◽  
Ben Cook ◽  
...  
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Optical Loss ◽  
Wide Band ◽  
Refractive Indices ◽  
Bulk Crystals ◽  
Wide Band Gap ◽  
Optical Effects ◽  
Transmission Studies ◽  
Novel Devices

ABSTRACTRecently, wide band gap II-IV-N2 semiconductors such as ZnSiN2, and ZnGeN2 and ZnSiGeN2 have been synthesized, but very little is known about their band structure, optical properties, or electronic properties. Bulk crystals are hard to synthesize because high temperatures and pressures are required. The success in growing II-IV-N2 films epitaxially by MOCVD creates interesting opportunities. The crystal structure of II-IV-N2 compounds is orthorhombic, and when grown on r-plane sapphire can provide a suitable template for GaN growth. Optical transmission studies of the band edge of ZnSiN2 and ZnSiGeN2 with varying Si and Ge percentages were conducted. The indirect nature of the band gap was investigated, and prism coupling was used to obtain the refractive indices in the visible and NIR portion of the spectrum. Although the crystal symmetry was orthorhombic, the refractive indices indicated uniaxial optical properties. Optical loss measurements indicate that the films are suitable for waveguides and novel devices based on birefringent optical effects.

Optical Properties of AlGaAsSb, AlGalnP, AlGaInAs, and GaInAsP for Optoelectronic Applications

1999 ◽  
Vol 579 ◽  
Author(s):  
M. Linnik ◽  
A. Christou
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Interband Transition ◽  
Theoretical Data ◽  
Quaternary Alloy ◽  
Refractive Indices ◽  
Incident Wavelength ◽  
Semiconductor Alloy ◽  
Transparent Region ◽  
Semi Empirical

ABSTRACTThe authors present calculations of quaternary III–V semiconductor alloy optical properties and the comparison of the theoretical data with available experimental results for AlGaAsSb, AlGaInP, AlGaInAs, and GaInAsP alloys. The investigation includes material's energy bandgap and refractive index calculations as a function of the incident wavelength in the transparent region, as well as the composition of the alloy. Optimization of the quaternary alloy refractive indices was obtained from a semi-empirical dielectric function calculations based on the interband transition contributions.

scholarly journals Aerosol scattering and absorption during the EUCAARI-LONGREX flights of the Facility for Airborne Atmospheric Measurements (FAAM) BAe-146: can measurements and models agree?

2012 ◽  
Vol 12 (15) ◽  
pp. 7251-7267 ◽  
Author(s):  
E. J. Highwood ◽  
M. J. Northway ◽  
G. R. McMeeking ◽  
W. T. Morgan ◽  
D. Liu ◽  
...  
Keyword(s):  
Optical Properties ◽  
Organic Carbon ◽  
Black Carbon ◽  
Growth Curves ◽  
Temporal Variations ◽  
Mie Scattering ◽  
Chemical Components ◽  
Refractive Indices ◽  
Hygroscopic Growth ◽  
Atmospheric Measurements

Abstract. Scattering and absorption by aerosol in anthropogenically perturbed air masses over Europe has been measured using instrumentation flown on the UK's BAe-146-301 large Atmospheric Research Aircraft (ARA) operated by the Facility for Airborne Atmospheric Measurements (FAAM) on 14 flights during the EUCAARI-LONGREX campaign in May 2008. The geographical and temporal variations of the derived shortwave optical properties of aerosol are presented. Values of single scattering albedo of dry aerosol at 550 nm varied considerably from 0.86 to near unity, with a campaign average of 0.93 ± 0.03. Dry aerosol optical depths ranged from 0.030 ± 0.009 to 0.24 ± 0.07. An optical properties closure study comparing calculations from composition data and Mie scattering code with the measured properties is presented. Agreement to within measurement uncertainties of 30% can be achieved for both scattering and absorption, but the latter is shown to be sensitive to the refractive indices chosen for organic aerosols, and to a lesser extent black carbon, as well as being highly dependent on the accuracy of the absorption measurements. Agreement with the measured absorption can be achieved either if organic carbon is assumed to be weakly absorbing, or if the organic aerosol is purely scattering and the absorption measurement is an overestimate due to the presence of large amounts of organic carbon. Refractive indices could not be inferred conclusively due to this uncertainty, despite the enhancement in methodology compared to previous studies that derived from the use of the black carbon measurements. Hygroscopic growth curves derived from the wet nephelometer indicate moderate water uptake by the aerosol with a campaign mean f(RH) value (ratio in scattering) of 1.5 (range from 1.23 to 1.63) at 80% relative humidity. This value is qualitatively consistent with the major chemical components of the aerosol measured by the aerosol mass spectrometer, which are primarily mixed organics and nitrate and some sulphate.

Optical Properties of Low Dielectric Constant Polyimides and Effects of Orientation

1993 ◽  
Vol 323 ◽  
Author(s):  
David C. Rich ◽  
Peggy Cebe ◽  
Anne K. St. Clair
Keyword(s):  
Dielectric Constant ◽  
Refractive Index ◽  
Optical Properties ◽  
Fluorine Content ◽  
Polymer Chains ◽  
Low Dielectric Constant ◽  
Refractive Indices ◽  
Electronic Polarizability ◽  
Low Dielectric ◽  
Preferential Alignment

AbstractControl of the refractive index in low dielectric constant polyimides through modification of chemistry and structure was investigated. The optical refractive indices of several low dielectric constant polyimides were measured, and the effects of orientation on optical anisotropy were determined. Refractive index in these polyimides was found to decrease with increasing fluorine content due primarily to the low electronic polarizability of the fluorine-carbon bonds. In zone drawn polyimides, refractive index was found to increase substantially in the direction of the draw, but decrease substantially normal to the draw direction. This was explained in terms of the preferential alignment of the polymer chains.

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