Abstract

The scalar-angular-spectrum approach is used to examine a focused extraordinary wave propagating along an arbitrary direction in a homogeneous uniaxial planar medium, and the Fraunhofer diffraction formula is generalized for this case. The size of the focal spot is found to be inversely proportional to an effective index, depending on the refractive indices and the propagation direction. The validity of the paraxial model is checked by nonparaxial (but scalar) numerical calculations. They show that the paraxial formulas predict the spot size correctly, but if the beam propagates neither parallel with nor perpendicular to the optic axis, they do not reproduce the symmetries of the amplitude distribution in the focal line.

© 1995 Optical Society of America

Nonparaxial description of reflection and transmission at the interface between an isotropic medium and a uniaxial crystal

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Beam propagation in uniaxial anisotropic media

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Basic elliptical Gaussian wave and beam in a uniaxial crystal

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Direction cosines and vectorial relations for extraordinary-wave propagation in uniaxial media

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Paraxial wave equation for the extraordinary-mode beam in a uniaxial crystal

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