THEORY OF TRANSLATIONAL ABSORPTION IN GASES

1961 ◽  
Vol 39 (1) ◽  
pp. 189-204 ◽  
Author(s):  
J. D. Poll ◽  
J. Van Kranendonk
Keyword(s):  
Absorption Coefficient ◽  
Infrared Absorption ◽  
Dipole Moments ◽  
Gas Mixtures ◽  
Absorption Coefficients ◽  
Monatomic Gas

The theory of translational infrared absorption in gases is developed. Invariant expressions for the integrated absorption coefficients are derived. The absorption coefficients are expanded in powers of the density, and the binary absorption coefficients are expressed in terms of a model for the induced pair dipole moments. Monatomic gas mixtures, diatomic gases, and diatomic–monatomic gas mixtures are considered in detail. As an application the binary absorption coefficient of the translational band of hydrogen is calculated.

COLLISION-INDUCED ABSORPTION OF COMPRESSED GASES IN THE FAR INFRARED, PART I

1965 ◽  
Vol 43 (5) ◽  
pp. 729-750 ◽  
Author(s):  
D. R. Bosomworth ◽  
H. P. Gush
Keyword(s):  
Fourier Analysis ◽  
Infrared Absorption ◽  
Michelson Interferometer ◽  
Far Infrared ◽  
Gas Mixtures ◽  
Experimental Techniques ◽  
Rare Gas ◽  
Absorption Coefficients ◽  
Induced Absorption ◽  
Separate Paper

A study is being made of the far infrared absorption occurring in compressed rare-gas mixtures, and compressed homonuclear diatomic gases. The region investigated lies between 20 and 400 cm−1. The spectra are obtained from the Fourier analysis of interferograms produced by a dynamic Michelson interferometer. It is possible to obtain accurate absolute absorption coefficients for broad bands using this method provided care is exercised in the analysis of the interferograms. The necessary precautions are discussed in detail. The precision of the method obtained in practice is demonstrated using the far infrared bands of hydrogen and nitrogen as examples. Only the experimental techniques are discussed in this paper; the detailed results follow in a separate paper.

scholarly journals Infrared Absorption and Its Sources of CdZnTe at Cryogenic Temperature

2022 ◽  
Author(s):  
Hiroshi Maeshima ◽  
Kosei Matsumoto ◽  
Yasuhiro Hirahara ◽  
Takao Nakagawa ◽  
Ryoichi Koga ◽  
...  
Keyword(s):  
Absorption Coefficient ◽  
Infrared Absorption ◽  
Cryogenic Temperature ◽  
Room Temperature ◽  
Wavelength Region ◽  
Room Temperature Resistivity ◽  
Absorption Model ◽  
Acceptor Level ◽  
Absorption Coefficients ◽  
Temperature Resistivity

AbstractTo reveal the causes of infrared absorption in the wavelength region between electronic and lattice absorptions, we measured the temperature dependence of the absorption coefficient of p-type low-resistivity ($$\sim 10^2~ \Omega \mathrm{cm}$$ ∼ 10 2 Ω cm ) CdZnTe crystals. We measured the absorption coefficients of CdZnTe crystals in four wavelength bands ($$\lambda =6.45$$ λ = 6.45 , 10.6, 11.6, 15.1$$~\mu $$ μ m) over the temperature range of $$T=8.6$$ T = 8.6 -300 K with an originally developed system. The CdZnTe absorption coefficient was measured to be $$\alpha =0.3$$ α = 0.3 -0.5 $$\mathrm{cm}^{-1}$$ cm - 1 at $$T=300$$ T = 300 K and $$\alpha =0.4$$ α = 0.4 -0.9 $$\mathrm{cm}^{-1}$$ cm - 1 at $$T=8.6$$ T = 8.6 K in the investigated wavelength range. With an absorption model based on transitions of free holes and holes trapped at an acceptor level, we conclude that the absorption due to free holes at $$T=150$$ T = 150 -300 K and that due to trapped-holes at $$T<50$$ T < 50 K are dominant absorption causes in CdZnTe. We also discuss a method to predict the CdZnTe absorption coefficient at cryogenic temperature based on the room-temperature resistivity.

INFRARED ABSORPTION OF DEUTERIUM INDUCED BY INTERMOLECULAR FORCES

1965 ◽  
Vol 43 (5) ◽  
pp. 793-799 ◽  
Author(s):  
S. Paddi Reddy ◽  
C. W. Cho
Keyword(s):  
Absorption Band ◽  
Absorption Coefficient ◽  
Infrared Absorption ◽  
Room Temperature ◽  
Intermolecular Forces ◽  
Absorption Coefficients ◽  
Fundamental Band ◽  
Molecular Parameters ◽  
The Individual ◽  
Gas Pressures

The pressure-induced fundamental infrared absorption band of deuterium has been investigated in the pure gas for gas pressures up to 250 atm at room temperature. The binary and ternary absorption coefficients were determined from the integrated absorption coefficients of the fundamental band at different densities of the gas. The splitting of the Q branch into two well-resolved components QP and QR was observed; the contours also exhibit pronounced S(0) and S(2) components with an indication of the S(1) and O(2) components. The existing theory and the available molecular parameters of deuterium were used to calculate the binary absorption coefficients of the individual lines of the O and S branches and of the quadrupole part of the Q branch. From these calculations and the experimental value of the total binary absorption coefficient of the fundamental band, the overlap part of the binary absorption coefficient of the Q branch was estimated.

The Propagation of Sound in Monatomic Gas Mixtures

1960 ◽  
Vol 75 (6) ◽  
pp. 898-904 ◽  
Author(s):  
R Holmes ◽  
W Tempest
Keyword(s):  
Gas Mixtures ◽  
Monatomic Gas

The Electrically Controlled Birefringence Measurement Influence of Liquid Crystal Caused by Absorption Effect in Infrared Region

2014 ◽  
Vol 875-877 ◽  
pp. 467-471
Author(s):  
Ning Wang ◽  
Xiao Xia Li
Keyword(s):  
Liquid Crystal ◽  
Absorption Coefficient ◽  
Approximate Method ◽  
Nematic Liquid Crystal ◽  
Infrared Region ◽  
Interference Method ◽  
Absorption Coefficients ◽  
Absorption Effect ◽  
Ordinary Light

The electrically controlled birefringence of nematic liquid crystal BL-009 was measured by polarized interference method. The influence of LC absorption effect, the birefringence variation, is discussed in this paper. The experiments results showed the influence to birefringence is big in infrared region. Not only the birefringence value is greatly different with that of unconsidering absorption effect, but also the gradient changing of birefringence curves is obvious. Furthermore, the electrically controlled birefringences of two conditions are compared when the absorption coefficients of ordinary light and the extraordinary light are nearly same and greatly different. The analysis demonstrated the approximate method of absorption coefficient is feasible.

The Use of Reverse Mirage Spectroscopy to Determine the Absorption Coefficient of Liquid Methanol at CO2 Laser Wavelengths

1989 ◽  
Vol 43 (1) ◽  
pp. 148-153 ◽  
Author(s):  
Dane Bićanić ◽  
Siegfried Krüger ◽  
Paul Torfs ◽  
Bruno Bein ◽  
Frans Harren
Keyword(s):  
Absorption Coefficient ◽  
Co2 Laser ◽  
Probe Beam ◽  
Laser Emission ◽  
Wavelength Region ◽  
Experimental Setup ◽  
Absorption Coefficients ◽  
Experimental Conditions ◽  
Liquid Samples

An experimental setup for performance of reverse mirage spectroscopy at CO2 laser wavelengths on liquid samples having high values of absorption coefficients is described. One and the same liquid is used as both the absorbing and deflecting medium. The Rosencwaig-Gersho theory has been applied, and the choice of experimental conditions that would enable determination of absorption coefficient β from the magnitude of photothermal signals measured at two different probe beam distances (probing locations) is discussed. The usefulness of this technique (essentially not inhibited by the requirements imposed on the sample's thickness) is tested on methanol having absorption coefficients β close to 300 cm−1 in the wavelength region covered by CO2 laser emission.

Light-induced absorption and optical damage in Sc-, Mg-, and Zn-doped near-stoichiometric LiNbO3

2018 ◽  
Vol 27 (03) ◽  
pp. 1850030 ◽  
Author(s):  
Junsheng Li ◽  
Youwen Liu ◽  
Huijie Zhang ◽  
Liangzun Tang ◽  
Chongjun He
Keyword(s):  
Steady State ◽  
Lithium Niobate ◽  
Absorption Coefficient ◽  
Ultraviolet Light ◽  
Infrared Absorption ◽  
Doping Level ◽  
Doping Concentration ◽  
Weak Absorption ◽  
Induced Absorption ◽  
Infrared Absorption Spectra

By measuring the ultraviolet-light-induced absorption in Sc-, Mg- and Zn-doped near-stoichiometric lithium niobate (LiNbO[Formula: see text], we find that the steady-state ultraviolet-light-induced absorption coefficient changes with respect to the doping concentration. There is a strong ultraviolet-light-induced absorption when doping concentration is below its photorefractive threshold and a really weak absorption when the crystal is highly doped. We also use OH[Formula: see text] infrared absorption spectra and the transmitted light spot distortion method to verify the result. Thus, we can determine if the doping level in these doped near-stoichiometric LiNbO3 crystals is above or below their photorefractive threshold by measuring the ultraviolet-light-induced absorption.

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