Re: De-polarize light?


"AES" <siegman@xxxxxxxxxxxx> wrote in message

"Adam Norton" wrote:


Since un-polarized light is actually just light that takes on random
polarization states versus time, it is impossible to truly de-polarize
light
without a time-varying optic. Although, you can argue that something
like a
Lyot depolarizer with a retardance much greater than the coherence length
of
the bandwidth being detected will be produce essentially depolarized
light.


This is IMHO a very good statement -- lots of physical understanding.

Right, as I recall, I was able to depolarize pretty well an initially
polarized He-Ne beam by having it go through a... small drop
of milk.

I suppose that the scattering due to the fat (?) particles within the milk
and their brownian motion played the role of the above time varying
optical gadget.

I assume that my explanation makes sense!

Truly speaking after going through the milk there was no "laser beam" to
speak of but a sort of small very bright source emitting pretty much into
4*pi steradian.

This is rather amusing and spectacular, not to mention cheap and easy.

To make the experiment last a little longer I used a colloidal solution of
I don't remember what (concocted by a chemist colleague) after being
inspired by observing the hot springs / pools in the Norris Basin of
Yellowstone National Park, some of which do contain colloidal solutions
and scatter light very nicely and spectacularly.

Truly speaking what I wanted was to get rid of undesirable speckle effects
which had so far bothered me greatly in an interferometry experiment.

It worked very well and maybe somebody here could work out the physics,
scattering, brownian notion wise and all and explain to us what was actually
going on.

Another chapter from my utterly fascinating biography.



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