[Laser] ~OT: High-power polarized light?

[n5gui at cox.net]

I do not know if it has been done.  Perhaps there are others on the list that have heard of such.

Years ago, I put up a post suggesting that it could be done.  I do not know of any benefit, just that it is a way to impress information on a light beam.

A very simple system would be to shift polarization by 90 degrees at the transmitter.  On receive, split the beam into two paths, each going through a polarizing filter so that one peaks on each of the transmitted segments.  Assuming there are no path related polarization effects, the beam would appear a non-polarized sensor to have the same intensity regardless of the information transmitted.  The intensity might fluxuate due to other effects.  Perhaps this could be used to compensate for "twinkle", or at a minimum mark un-reliable signals.  Said another way, the two polarization paths should compliment each other.  Where they have the same state, then the data is corrupt.

Another way to use two differing polarized paths is to sent two data streams:  different data, compressed data, or redundancy.

Might be interesting to tinker with.  

James
 n5gui



---- Tom Becker <GTBecker at RighTime.com> wrote: 
>  > ... Reflection of such a beam on nonmetallic surfaces produces 
> partially up to totally linear polarized light...
> 
> Hmmm.  If a beam is fired through a pair of narrowly-spaced parallel 
> reflectors such that several grazing reflections occur before the beam 
> emerges, is the beam likely to be well linearly-polarized?
> 
> Has variable polarization been used as a modulation mode?
> 
> 
> Tom
> 
> 
> 
> ______________________________________________________________
> Laser mailing list
> Home: http://mailman.qth.net/mailman/listinfo/laser
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Laser at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html