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The electromagnetic slowness surfaces for PZT2
on the other hand,
do not show any anomalous behavior.
PZT2 is a strongly birefringent material. Thus we can clearly see the two
wavetypes propagating at speeds comparable to that of electromagnetic waves.
Both slowness surfaces
touch at the vertical axis (symmetry axis).
The inside surface has an electric displacement direction which is
orthogonal to that on the outside surface
(a manifestation of Maxwell's equations). The shape is ellipsoidal according to
the structure of the electric permittivity and magnetic permeability tensors.
Including the piezoelectric stress coefficients in the calculation results
in only minor effects on those two wavetypes.
In quartz the propagation velocities of the two
electromagnetic waves are very close; they are only
distinguishable by looking at both the outside and the inside slowness surface.
The inside surface has
an electric displacement direction which is orthogonal to that on the
outer surface
(a manifestation of Maxwell's equations). The shape is ellipsoidal according to
the structure of the electric permittivity and magnetic permeability tensors.
Again, for the coupled propagation, the changes are very small.
Next: Cross-coupled slowness surfaces
Up: CHARACTERISTIC SURFACES
Previous: ``Elastic'' slowness surfaces
Stanford Exploration Project
1/13/1998