Propagation of phase transverse to the imposed magnetic field

Abstract

When the direction of phase propagation is perpendicular to the direction of the imposed magnetic field, we have what is known as transverse propagation (¸ _p = 1/2 π). For transverse propagation the direction of group propagation is also perpendicular to the direction of the imposed magnetic field (θ _g = 1/2 π) This follows from the fact that the expressions for n ² in Equations (5.36) are unchanged if θ _p is replaced by π — θ _p . Consequently a diagram such as Figure 6.2 showing surfaces of constant ω in k space is symmetrical about the coordinate plane perpendicular to the direction of the imposed magnetic field. Normals to a surface where it crosses the k ₁ axis are therefore in the k ₁ direction. For transverse propagation, the directions of group and phase propagation coincide, but not the magnitudes.