Re: 90 degree prisms

Post:

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That's a graduate E and M problem (see Jackson: evanescent waves). Why
would you do this demo a class other than graduate E & M.

Sam

Duane Warn wrote:

> Hi Gordon,
>
> If you take two 45-45-90 prisms and put them together to make a square
> and hold them together with a rubber band, and shine a laser through
> them, there is a tunneling effect at the surface if the faces are very
> smooth. When the prisms are separate very slightly, the intensity
> drops off exponentially on the beam going straight through. This
> shows that even when you have total internal reflection, that part of
> the wave energy is on the outside of the glass. The dept. chair likes
> that demo.
>
> Have a good holiday weekend, and it's good to have Zig back on task.
>
> Duane
> Boise State U.
>
> >>> fizzix@netmcr.com 9/2/2004 2:30:27 PM >>>
> Do you mean that wouldn't reflect at the surfaces that were touching?
> You'd probably have to put some drops of liquid with an index of
> refraction the same as the glass.
> Gordon
>
> Duane Warn wrote:
>
> > Good After....Hay it's time to go home,
> >
> > Where is a good place to find some 40, 40, 90 degree prisms that are
> > of good enough quality that when held next to each other don't reflect?
> >
> > Duane
> > Boise State U.
> >
> >
> >
>

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That's a graduate E and M problem (see Jackson: evanescent waves). Why
would you do this demo a class other than graduate E & M.

Sam

Duane Warn wrote:

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Hi Gordon,

If you take two 45-45-90 prisms and put them together to make a
square and hold them together with a rubber band, and shine a laser
through them, there is a tunneling effect at the surface if the faces
are very smooth. When the prisms are separate very slightly, the
intensity drops off exponentially on the beam going straight through.
This shows that even when you have total internal reflection, that part
of the wave energy is on the outside of the glass. The dept. chair
likes that demo.

Have a good holiday weekend, and it's good to have Zig back on
task.

Duane

Boise State U.

>>> fizzix@netmcr.com 9/2/2004 2:30:27 PM >>>

Do you mean that wouldn't reflect
at the surfaces that were touching?

You'd probably have to put some drops of liquid with an index of

refraction the same as the glass.

Gordon

Duane Warn wrote:

> Good After....Hay it's time to go home,

>

> Where is a good place to find some 40, 40, 90 degree prisms that
are

> of good enough quality that when held next to each other don't
reflect?

>

> Duane

> Boise State U.

>

>

>