Re: Ref: Laser Metrology/ Encoders

--- In CAD_CAM_EDM_DRO@yahoogroups.com, stan <stan.distortion@...> wrote:

> Can polorised glass filter these waves, as in if a wave is
> rising and hits the glass it will be blocked and if it is falling it
>will pass through?

No, polarisers reject light based on it's orientation, light has a
"way up".

http://en.wikipedia.org/wiki/Polarizer

I can see what you are trying to say but remember that the light
although of fixed wavelength is moving at the speed of light. In
order to do what something *like* you suggest you need a reference
also moving at the speed of light, this is the reference beam of an
interferometer. Once you have two beams interfering then you can
forget about time and imagine the waves are frozen in time (like some
bend wire). When you move a mirror that one of the beams is bouncing
off you essentially slide one beam past the other. This causes
oscillating intensity at a plane where they are combined as they
interfere constructively and destructively.

Graham