High-resolution absorption coefficient and refractive index spectra of common pollutant gases at millimeter and THz wavelengths

In this study, some optical properties were studied of the pure vinyl polyvinyl alcohol (PVA) nanopolymer (German origin). Under the influence of different temperatures and pressures of PVA. Where 25 samples were prepared for the purpose of conducting the research. Which studied the study of these samples was done by recording the absorbance and transmittance spectra of the wavelengths (200-900) nm. From them, absorbance, transmittance, reflectivity, absorption coefficient, refractive index, extinction coefficient, complex dielectric constant were calculated. At different temperatures (25,40, 80, 120, 160)°C. And with different pressures within the range (7.5,8,8.5,9,9.5) MPa. The results are that the permeability of the polymer (PVA) at different temperatures for each pressure decreases with increasing temperature, and that all other calculated optical properties increase with increasing temperature.

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The Influence of Crude Oil Carbon Content, Sulfur Content and Density on Absorption Coefficient and Refractive Index in the 0.2-2.5THz Band

10.1109/irmmw-thz50926.2021.9567130 ◽

2021 ◽

Author(s):

Haiqing Huang ◽

Xuemin Li ◽

Qiuhong Cao ◽

Hongmei Lin ◽

Qingjian Zhang ◽

...

Keyword(s):

Refractive Index ◽

Absorption Coefficient ◽

Crude Oil ◽

Carbon Content ◽

Sulfur Content

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THEORETICAL MODEL FOR THE CALCULATION OF OPTICAL PROPERTIES OF GOLD NANOPARTICLES

Journal of Nonlinear Optical Physics & Materials ◽

10.1142/s0218863510005297 ◽

2010 ◽

Vol 19 (03) ◽

pp. 427-436

Author(s):

A. MENDOZA-GARCÍA ◽

A. ROMERO-DEPABLOS ◽

M. A. ORTEGA ◽

J. L. PAZ ◽

L. ECHEVARRÍA

Keyword(s):

Gold Nanoparticles ◽

Refractive Index ◽

Optical Properties ◽

Theoretical Model ◽

Absorption Coefficient ◽

Molecular System ◽

Two Dimensional ◽

Box Models ◽

Solvent Environment ◽

Absorption And Dispersion

We have developed an analytical method to describe the optical properties of nanoparticles, whose results are in agreement with the observed experimental behavior according to the size of the nanoparticle under analysis. Our considerations to describe plasmonic absorption and dispersion are based on the combination of the two-level molecular system and the two-dimensional quantum box models. Employing the optical stochastic Bloch equations, we have determined the system's coherence, from which we have calculated expressions for the absorption coefficient and refractive index. The innovation of this methodology is that it allows us to take into account the solvent environment, which induce quantum effects not considered by classical treatments.

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The scattering of light by turbid media.–Part II

Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character ◽

10.1098/rspa.1931.0065 ◽

1931 ◽

Vol 131 (817) ◽

pp. 464-475 ◽

Cited By ~ 43

Keyword(s):

Refractive Index ◽

Absorption Coefficient ◽

Spherical Shell ◽

Direct Observation ◽

Single Particle ◽

Unit Volume ◽

Incident Light ◽

Parallel Beam ◽

Photometric Observations ◽

Transmission And Reflection

In Part I it was shown how the values of the transmission and reflection of a sheet of a medium containing particles in suspension can he calculated. First the amounts of light scattered in the forward and forward directions from a single particle were determined; from these results the transmission 1 and rejection R for diffuse incident light were found for a layer of the disusing medium, when the effects of boundary reflections are negligible. At this stage, the expressions developed apply to a mist or fog consisting of particles suspended in air. Finally it was shown how, if the particles are suspended in some other medium, having a different refractive index from that of air, the transmission and reflection ז and p can be expressed in terms of T and R and the surface rejection coefficients. The more general expressions, for the case when the incident light is a parallel beam, were also developed. We shall now show how the absorption coefficient μ can be determined from photometric observations. As a check on the theory, we shall deduce the diameter D of the particles and the number N present per unit volume and compare these calculated values with those found by direct observation, Finally, the necessary modifications of the theory will be made to cover the case when the diffusing medium is in the form of a spherical shell.

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