P3D Re: stereo laser pointer

[Tom Hubin <thubin@xxxxxxxxx>]

Hello Ron,

> Any hackers/pros out there put together a stereo laser pointer?
> thanks~
> ron labbe

What is a stereo laser pointer? 

I am going to guess that it is a laser pointer that can be viewed while
wearing polarized lenses. A pointer that is not polarized or is
polarized such that either eye can see it with no special way of
handling the pointer. 

If that is what you need then start with a standard laser pointer that
is linearly polarized. Then cover the lens with a piece of quarter wave
retarder (buy from Edmunds Scientific or a free sample from somewhere).
Then rotate the retarder until the light is circularly polarized. You
will know when this occurs because the laser spot on the screen will be
equally visible no matter what the orientation of your polarized viewing
glasses. Each eye will see half the light at any orientation of the
laser pointer.

A more elaborate method would involve 2 laser pointers polarized
perpendicular to each other. Wear polarized viewing glasses while you
set this up. Rotate one laser pointer so that it cannot be seen with the
left eye. Rotate the other laser pointer so that it cannot be seen by
the right eye. Strap them together so that they are pointed to the same
place on the screen. Now you may rotate the combined pointer as you wish
and both eyes will always see the equivalent brightness of one pointer.

Tom Hubin
thubin@xxxxxxxxx
AO Systems Design


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