Re: A stinking explanation ?

[John Mallinckrodt <ajmallinckro@CSUPOMONA.EDU>]

On Wed, 22 Sep 1999, Ludwik Kowalski wrote:

> I will think about what John wrote. Meanwhile here are two
> quick clarifications.
>
> John Mallinckrodt wrote:
>
> > This may be technically true, but I think it is a little misleading.
> > To consider a wave "extraordinary" it must have at least some
> > component of its E-field parallel to the optic axis.  (I am restricting
> > my consideration to uniaxial substances like quartz.)  If a wave
> > propagates along the optic axis, then both linear polarizations are
> > necessarily identical in every respect.
>
> Why do you think a parallel component of E is necessary?
> The E-wave is polarized in the principal plane while the
> O-wave is polarized perpendicularly to the E-wave. In that
> way they are not identical. I am also considering uniaxial
> crystals only.

I guess I don't understand the reference to "the" principal plane.  In a
uniaxial crystal *any* plane that contains the optic axis is a principal
plane.  Thus *every* linearly polarized wave has its E-field in a
principal plane and this characteristic certainly cannot be used to
distinguish e-waves from o-waves.  The distinction is based on whether or
not the E-field is perpendicular to the optic axis.  For o-waves the E
field is perpendicular to the optic axis; for e-waves it is not, hence my
comment that an e-wave has at least some component of its E-field parallel
to the optic axis.

John Mallinckrodt      mailto:ajm@csupomona.edu
Cal Poly Pomona          http://www.csupomona.edu/~ajm