Complex Refractive Index Of Medium Research Articles

The refractive angle of light propagation at absorbing media interface

The light propagation within an absorbing medium and the refraction at the interface between absorbing medium are studied. By using the unit vectors denoting the planes of constant field amplitude and constant phase respectively, with the expression for the light propagation, using the corresponding boundary conditions, the refractive angle of the light through the interface of two absorbing medium have been obtained. This work can be applied to the refraction event at the interface of the media, wherein either/both of them is/are absorbing or transparent. Numerical analysis shows that, the refraction angle depend not only on the incident angle, the complex refractive index of medium but also on the angle between the two unit vectors, and the angle of refraction increases first and then decreases during the increasing of incident angle; the angle between the unit vectors has greater effects on refraction angle in absorbing medium/transparent medium than in the two absorbing medium interface.

Nonstationary theory of polarized light pulse propagation through a four-level resonant medium with allowance for nonlinear complex refractive index of medium

Nonstationary theory of polarized light pulse propagation through the medium with resonant transition 1/2 -1/2 is developed with taking into account complexity of the medium nonlinear refractive index. The theory is developed based on the irreducible tensor formalism which allows diagonalizing relaxations matrix and introducing effective decay times associated with the population relaxation, as well as relaxation of coherence between magnetic sublevels of the resonant system. It is shown that as a result of interference of magnetic sublevels in the polarized radiation field the inversionless amplification of radiation occurs due to optical pumping process. The dependence of inversionless amplification on the line broadening and resonance detuning is studied.

Dispersion relations for evaluating the complex refractive index of medium without the information of its thickness

A general method to obtain the complex refractive index of a medium from absorbance, or alternatively from optical path length data, without knowing the sample thickness is proposed. The method can be formulated in any spectral range and it is here applied particularly in the terahertz spectral range to both simulated and experimental data. The key idea is the derivation of nonconventional dispersion relations that partly resemble traditional Kramers-Kronig relations. The method is shown to work well in extracting the complex refractive index of a drug system and a precipitated calcium carbonate.

Some remarks on the calculation of the complex refractive index of medium in terahertz reflection spectroscopy

AbstractThis paper presents a technique, based on dispersion theory, for the analysis of terahertz reflection spectroscopy data measured using ellipsometric methods. Formulas for the complex reflection coefficient provide simpler equations than those used in conventional ellipsometry for resolving the complex refractive index in the THz spectral range. It is proposed that a reflection coefficient ratio yields information on the surface roughness when probing a surface by THz radiation. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)