Light uniaxial materials

Light Propagation through Uniaxial Materials (Jones Method)... 

Conoscopic images under white light illumination, (a and b) Uniaxial material an interference pattern consisting of two intersecting black bars (termed isogyres) forming Maltese cross-Kke pattern and circular distributions of interference colors (c) biaxial material. 

A uniaxial material has one optic axis and a biaxial material has two. A birefringent material appears to be isotropic when a plane light wave passes through it along an optic axis. In terms of the indicatrix, the cross section in the... 

Material like sapphire, which is a uniaxial crystal, does not show nonlinear fluorescence, and direct visualization of filaments is, consequently, not an option. However, the effect of rotation of plane polarization can also be probed in such materials by monitoring the spatial size of the white light disc, and of the spectrum of the super continuum that is produced. Figure 5.3 depicts some typical results obtained with 3 mm long sapphire crystals. The extent of the supercontinuum spectrum is seen to vary as a function of polarization angle. The supercontinuum spectrum has two components [39] symmetric broadening about the incident wavelength that is essentially ascribable to... 

Propagation of light through a uniaxial, anisotropic material. 

This describes the x and y components of the electric vector of light propagating along the z axis and through an isotropic material of refractive index n. Evidently, the light has had a prior interaction with an anisotropic material and these two components have differing amplitudes and phases. For example, in section 1.2.1, a sample with a uniaxial dielectric tensor was observed to induce a phase difference, 8X - 8y = (2k/X) (n, - n2) d, where... 

The anisotropy of the optical properties in the wavelength range of visible light is generally described by the birefringence An, defined by the first part of Equation 8.12. A birefringent material has different refractive indices in two different principal axis directions. For a specimen that is under uniaxial tension, nn and n denote the refractive indices parallel and perpendicular to the orientation direction, respectively. The second part of Equation 8.12 defines the stress-optic coefficient C0 describing the dependence of An on the applied stress. 

Optical investigations of smetic liquids indicated a behaviour of uniaxial or biaxial crystals depending on the special type of material. They are usually positive birefringent, which means that with transmitted light the ordinary beam has a lower refractive index. The nematic liquid is optically positive. 

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