Re: A stinking explanation ?

[brian whatcott <inet@INTELLISYS.NET>]

At 10:53 9/22/99 -0400, you wrote:
> Consider a quartz plate whose optical axes are also normal to its flat
> surfaces. In such plate a linearly polarized light, at zero angle of
> incidence, will remain linearly polarized at the exit, no matter how
> thick is the plate.... Frenel's
> "explanation" of optical activity (rotation of the plane of
> polarization by a quartz plate).
> According to Jenkins and White (page 588) Frenel's explains the effect
> by assuming that "two circular vibrations move forward with slightly
> different velocities."
>
> Please explain how velocities of right-handed and left-handed components
> of linearly polarized light can be different for a beam parallel to the
> optical
> axes. ...
> Ludwik Kowalski

The thickness dependent rotation in either sense (21.7 deg/mm for
Sodium D, at 20 deg C) of a linearly polarized beam through a quartz
along its optical axis and normal to its end faces is said to be
associated with structural features of the crystal which are abolished
in fused quartz.
 Fresnel's experimental support for his 'delta v' idea was quite elegant:
a stack of laevo and dextro rotatory prisms would at length deliver two
beams seperated spatially, and each of which was circularly polarised in
opposite hands.  But I note that though the entrance and exit faces were
normal to the input beam, the intermediate faces were not perpendicular
to it.




brian whatcott <inet@intellisys.net>
Altus OK