OPTICAL WAVE-PACKET PROPAGATION IN NONISOTROPIC MEDIA

We show that the propagation equation for the slowly varying envelope of the electric field in a dispersive nonisotropic medium contains ter ms that rotate the 3D wave packet of an optical pulse propagating as a n extraordinary wave about an axis perpendicular to the propagation ve ctor. It also possesses Fresnel diffraction coefficients that depend n ot only on the refractive index but also its derivatives with respect to direction. An analytic expression for the slowly varying envelope i s obtained for an initial Gaussian wave packet by keeping terms up to second order in the wave equation for the slowly varying envelope.