Ordinary index of refraction

Uniaxial (birefrigerent) crystals have an index of refraction that depends on the projection of the oscillating electric field of linearly polarized radiation on the unique axis (the optic axis) of the crystal. Consider the plane defined by the optic axis of the uniaxial crystal, c, and the propagation direction of the oq beam, which is described by the unit vector, k = k uji)/ k(ui ). Light polarized perpendicular to the c,k plane is called the ordinary ray and propagates according to the ordinary index of refraction,... 

Because the voltage on the electrodes is designed to change as the square of the distance from the center of the lens device, a square change in the LC index of refraction occurs if the LC is operated in the linear portion of its characteristic curve. Figure 5.5 illustrates LC molecules in their rotated positions as results of the different voltage levels generated by the resistor bias network in the device, n represents the extraordinary index of refraction of the LC material, is the ordinary index of refraction, and dn = > 0 is... 

In these geometries, the sample cell is usually observed in the transmitted light with crossed polarizers inserted in 45° orientation to the director tilt plane. While the ordinary polarized light in the birefringent medium always experiences the ordinary index of refraction and is unaffected by the deformation, the optical path of the extraordinary wave is sensitive to the director tilt. Both waves are brought to interference at the analyser and the optical interference can be related in a direct way to the director deflection. Saupe first used this magneto-optical method with splay geometry to determine the splay and bend constants of p-azoxyanisol (PAA) [13]. 

The absolute index for all ordinary transparent substances is greater than 1 (see Table 1) but there are some special cases (X-rays and light in metal films, which are discussed below) for which the index of refraction is less than unity. Since the absolute index for air exceeds unity by less than 0.0003, the relative indices for solids and liquids in air are very nearly equal to their absolute indices. It should be noted that since the refractive mdex vanes with the wavelength, any exact statement of its value must specify the wavelength to which it refers in Tables it is usually given for sodium light of frequency 5.893A. See also Dispersion. 

Looking at the phenomenon of optical absorption by the medium from the viewpoint of classical wave mechanics, we see that the attenuation of electromagnetic radiation can be attributed to the interaction of the oscillating electric vector with the medium. Any phenomenon involving periodic oscillations can be decomposed to real and imaginary components. Thus, the ordinary refractive index n is the real part of the index of refraction n, which can be written as... 

The index of refraction is a function of both wavelength and temperature. Usually the temperature is specified to be 20 or 25°C. The former is more in accord with past practice, but the latter is somewhat easier to maintain with a constant-temperature bath under ordinary laboratory conditions. The wavelength is usually specified to be that of the yellow sodium D line (a doublet, 589.0 and 589.6 run), and the index is given the symbol nj). 

Figure 18. Refractive index dispersion in evaporated thin films of pure (triangles), monosubstitued (circles) and disubstitued fumrot (squares) (cf. Fig. 10). Full figures show ordinary whereas the open the extraordinary index of refraction, respectively. Solid lines are Sellmeier fits...

The interest in quantum interference stems from the early 1970s when Agarwal [4] showed that the ordinary spontaneous decay of an excited degenerate V-type three-level atom can be modified due to interference between the two atomic transitions. The analysis of quantum interference has since been extended to other configurations of three- and multilevel atoms and many interesting effects have been predicted, which can be used to control optical properties of quantum systems, such as high-contrast resonances [5,6], electro-magnetically induced transparency [7], amplification without population inversion [8], and enhancement of the index of refraction without absorption [9]. 

Isometric, orthorhombic, tetragonal, and monoclinic forms of tricalcium aluminate (CajAl O ) with a melting point of approximately 1542°C are termed CjA in the cement industry. Tricalcium aluminate normally consists of uniform, small, xenomorphous to rectangular crystals (1 to 60 pm) in low-alkali or alkali-free clinker. CjA may comprise as much as 18 percent in ordinary clinker. Crystals show poor cleavage parallel to (001), conchoidal fracture, and a hardness of 6. Tricalcium aluminate is normally isotropic in cross-polarized light, colorless (in white cement) to tan and brown in transmitted light in ordinary portland cement, with an index of refraction of 1.710. It reflects gray on unetched polished surfaces and etches blue to... 

Birefringence, or double refraction, is the decomposition of a beam of light into two rays, the ordinary ray and the extraordinary ray, when it passes through anisotropic materials. Birefringence is measured as the difference between the greatest and the lowest index of refraction of an anisotropic and transparent material ... 

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