Wavelength Dependence of the Photorefractive and Photodiffractive Properties of Holographic Thin Films Based on Bacteriorhodopsin

1990 ◽  
Vol 218 ◽  
Author(s):  
Robert R. Birge ◽  
K. Can Izgi ◽  
Jeffrey A. Stuart ◽  
Jack R. Tallent
Keyword(s):  
Refractive Index ◽  
Large Change ◽  
Wave Theory ◽  
Wavelength Dependence ◽  
Solute Concentration ◽  
Maximum Efficiency ◽  
Optical Absorption Spectroscopy ◽  
Phase Component ◽  
Absorption Component ◽  
Negative Band

AbstractThe photorefractive and photodiffractive properties of a 2 × 10−3 M, 30μim thin film of bacteriorhodopsin at - 40°C are analyzed by using optical absorption spectroscopy, the Kramers- Kronig transformation and coupled wave theory. Conversion of M to bR generates a dispersion in the refractive index that has a broad negative band from 450 to 540 nm [Δn500nm - -0.0016] and a broad positive band from 590 to 700 nm [Δn605nm - 0.0016]. The large change in refractive index for moderate solute concentration is due to the formation of the protonated Schiff base chromophore in bR which generates a large red shift in the absorption spectrum as well as a large increase in oscillator strength. The integrated diffraction efficiency from 300 - 800nm is dominated by refractive index contributions (ηphase) which are maximum in regions of minimal bR and M absorption. The maximum in the refractive (phase) component occurs at 451 nm (ηphase - 9.7%) whereas the maximum in the absorption component occurs at 575 nm (ηabs - 2.2%). The maximum efficiency of diffraction is observed at ∼440 nm (ηtotal - 10.7%). Adequate diffractive performance for most applications is predicted for write wavelengths in the regions 380 - 420 & 500 - 650 nm and for read wavelengths from 380 to 740 nm.

Stress Whitening in Polypropylene. I. Light Scattering Theory and Model Experiments

1995 ◽  
Vol 60 (11) ◽  
pp. 1875-1887 ◽  
Author(s):  
Jaroslav Holoubek ◽  
Miroslav Raab
Keyword(s):  
Refractive Index ◽  
Light Scattering ◽  
Incident Light ◽  
Polymeric Materials ◽  
Wavelength Dependence ◽  
Theoretical Background ◽  
Surrounding Matrix ◽  
Embedded Particles ◽  
The One ◽  
Stress Whitening

Theoretical background for an optical method is presented which makes it possible to distinguish unambiguously between voids and particles as light scattering sites in polymeric materials. Typical dependences of turbidity as a function of diameter of scattering elements, their volume fractions and also turbidity curves as a function of the wavelength of the incident light were calculated, based both on the Lorenz-Mie theory and the fluctuation theory. Such dependences calculated for polypropylene-containing voids on the one hand and particles, differing only slightly from the surrounding matrix in their refractive index, on the other hand, are markedly different. The most significant results are: (i) Turbidity is at least by two orders of magnitude larger for voids in comparison to embedded particles of ethylene-propylene (EPDM) rubber of the same size, concentration and at the same wavelength. (ii) The wavelength dependence of turbidity for EPDM particles and the inherent refractive index fluctuations in the polypropylene matrix is much steeper as compared to voids for all considered diameters (0.1-10 μm). Thus, the nature of stress whitening in complex polymeric materials can be determined from turbidity measurements.

scholarly journals Scattering and Absorption Cross-sections of Atmospheric Gases in the Ultraviolet-Visible Wavelength Range (307–725 nm)

2020 ◽  
Author(s):  
Quanfu He ◽  
Zheng Fang ◽  
Ofir Shoshamin ◽  
Steven S. Brown ◽  
Yinon Rudich
Keyword(s):  
Refractive Index ◽  
Wavelength Range ◽  
Cross Sections ◽  
Rayleigh Scattering ◽  
Dispersion Relations ◽  
Optical Absorption Spectroscopy ◽  
Absorption Cross ◽  
Atmospheric Gases ◽  
Scattering Cross ◽  
Scattering Cross Sections

Abstract. Accurate Rayleigh scattering and absorption cross-sections of atmospheric gases are essential for understanding the propagation of electromagnetic radiation in planetary atmospheres. Accurate extinction cross-sections are also essential for calibrating high finesse optical cavities and differential optical absorption spectroscopy and for accurate remote sensing. In this study, we measured the scattering and absorption cross-sections of carbon dioxide, nitrous oxide, sulfur hexafluoride, oxygen, and methane in the continuous wavelength range of 307–725 nm using Broadband Cavity Enhanced Spectroscopy (BBCES). The experimentally derived Rayleigh scattering cross-sections for CO2, N2O, SF6, O2, and CH4 agree with refractive index-based calculations, with a difference of 1.5 % and 1.1 %, 1.5 %, 2.9 %, and 1.4 % on average, respectively. The O2-O2 collision-induced absorption and absorption by methane are obtained with high precision at the 0.8 nm resolution of our BBCES instrument in the 307–725 nm wavelength range. New dispersion relations for N2O, SF6, and CH4 were derived using data in the UV-vis wavelength range. This study provides improved refractive index dispersion relations, n-based Rayleigh scattering cross-sections, and absorption cross-sections for these gases.

THIN-LAYER HOLOGRAPHIC PHOTOPOLYMER MATERIALS WITH A LARGE CHANGE IN THE REFRACTIVE INDEX

2021 ◽  
Vol 57 (6) ◽  
pp. 29-37
Author(s):  
D. I. Derevianko ◽  
E. F. Pen ◽  
V. V. Shelkovnikov ◽  
S. I. Aliev
Keyword(s):  
Refractive Index ◽  
Thin Layer ◽  
Large Change

Temperature and wavelength dependence of refractive index of zircon and hafnon

2004 ◽  
Vol 26 (3) ◽  
pp. 305-311 ◽  
Author(s):  
Cameron Tanner ◽  
Karen Geisinger ◽  
Raja Wusirika
Keyword(s):  
Refractive Index ◽  
Wavelength Dependence

The Effect of Refractive Index of the Medium on the Position of the Camera Lens in Schlieren Optics

1973 ◽  
Vol 51 (20) ◽  
pp. 3309-3312 ◽  
Author(s):  
L. Ivan Epstein ◽  
Percival Nixon ◽  
Alfred J. Richard
Keyword(s):  
Refractive Index ◽  
Linear Relation ◽  
Large Change ◽  
Optic Axis ◽  
Liquid Column ◽  
Camera Lens ◽  
Component Systems ◽  
Schlieren Optics

A linear relation has been established between the plane of focus for schlieren optics in the ultracentrifuge cell along the optic axis, and the refractive index of the liquid contained in the cell. Such a relation shows that there occurs a defocussing effect when a large change in refractive index is generated in the liquid column during centrifugation of multi-component systems.

scholarly journals Composition and wavelength dependence of the refractive index in Cd1−xMnxTe epitaxial layers

1992 ◽  
Vol 60 (18) ◽  
pp. 2192-2194 ◽  
Author(s):  
D. W. Schubert ◽  
M. M. Kraus ◽  
R. Kenklies ◽  
C. R. Becker ◽  
R. N. Bicknell‐Tassius
Keyword(s):  
Refractive Index ◽  
Wavelength Dependence ◽  
Epitaxial Layers

scholarly journals Initial investigation of the wavelength dependence of optical properties measured with a new multi-pass Aerosol Extinction Differential Optical Absorption Spectrometer (AE-DOAS)

2012 ◽  
Vol 5 (4) ◽  
pp. 709-721 ◽  
Author(s):  
R. T. Chartier ◽  
M. E. Greenslade
Keyword(s):  
Refractive Index ◽  
Optical Absorption ◽  
Radiative Forcing ◽  
Wavelength Dependence ◽  
Polystyrene Latex ◽  
Light Extinction ◽  
Aerosol Extinction ◽  
New Instrument ◽  
The Impact ◽  
Absorption Spectrometer

Abstract. Atmospheric aerosols directly affect climate by scattering and absorbing radiation. The magnitude of the impact is dependent upon the wavelength of light, but is often estimated near 550 nm. When light scattering and absorption by aerosols is approximated, the wavelength dependence of the refractive index for specific components is lost. As a result, climate models would have inherent uncertainties for aerosol contributions to radiative forcing when considering the entire solar spectrum. An aerosol extinction differential optical absorption spectrometer has been developed to directly measure aerosol extinction at mid-ultraviolet to near infrared wavelengths. The instrument consists of a spectrometer coupled to a closed White-type multi-pass gas cell with an adjustable path length of up to approximately 20 m. Laboratory measurements of various gases are compared with known absorption cross sections. Additionally, the extinction of monodisperse samples of polystyrene latex spheres are measured and compared to Mie theory generated with refractive index values from the literature to validate the new instrument. The polystyrene experiments also emphasize the ability of the new instrument to retrieve the wavelength dependent refractive index, especially in the ultraviolet wavelength regions where variability is expected. The spectrometer will be a significant advancement for determining wavelength dependent complex refractive indices in future laboratory studies as well as provide the ability to monitor ambient aerosol light extinction.

scholarly journals Evaluating different methods for elevation calibration of MAX-DOAS instruments during the CINDI-2 campaign

2019 ◽  
Author(s):  
Sebastian Donner ◽  
Jonas Kuhn ◽  
Michel Van Roozendael ◽  
Alkiviadis Bais ◽  
Steffen Beirle ◽  
...  
Keyword(s):  
Surface Albedo ◽  
Wavelength Dependence ◽  
Field Of View ◽  
Optical Absorption Spectroscopy ◽  
Measuring Instruments ◽  
Measuring Systems ◽  
White Stripe ◽  
Bright Stripe ◽  
Using Data ◽  
Work First

Abstract. We present different methods for in-field elevation calibration of MAX-DOAS (Multi AXis Differential Optical Absorption Spectroscopy) instruments that were applied and inter-compared during the second Cabauw Intercomparison campaign for Nitrogen Dioxide measuring Instruments (CINDI-2). One necessary prerequisite of consistent MAX-DOAS retrievals is a precise and accurate calibration of the elevation angles of the different measuring systems. Therefore, different methods for this calibration were applied to 12 instruments from 11 groups during the campaign and the results were inter-compared. This work first introduces and explains the different methods, namely far and near lamp measurements, white/bright stripe scans and horizon scans, using data and results for only one (mainly the MPIC) instrument. In the second part, the far lamp measurements and the horizon scans are examined for all participating groups. Here, the results for both methods are first inter-compared for the different instruments and secondly, the two methods are compared amongst each other. All methods turned out to be well-suited for the calibration of the elevation angles of MAX-DOAS systems, with each of them having individual advantages and drawbacks. Considering the results of this study, the uncertainties of the methods can be estimated as ± 0.05° for the far lamp measurements, ± 0.1° to ± 0.3° for the horizon scans, and around ± 0.1° for the white stripe and near lamp measurements. When comparing the results of far lamp and horizon scan measurements, a spread of around 1° in the elevation calibrations is found between the participating instruments for both methods. This spread is on the order of a typical field of view (FOV) of a MAX-DOAS instrument and therefore, affecting the retrieval results. Further, a consistent (wavelength dependent) offset of 0.31° and 0.40° between far lamp measurements and horizon scans is found, which can be explained by the fact that, despite the flat topography around the measurement site, obstacles such as trees might mark the visible horizon during daytime. The observed wavelength dependence can be explained by surface albedo effects. Lastly, the results are discussed and recommendations for future campaigns are given.

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