one way filter

[tmh556]

Hi,
I was wondering if anybody knew of a filter that allows light to pass through it only one way. From the other side, the surface of the filter is shiny so light reflects off of it. Ideally, almost all of the light would be able to pass through it from one side and almost all of the light would reflect off of it from the other side. Thanks, Tom

 

[IRstuff]

Other that knowing that it's impossible for a general case?

TTFN

FAQ731-376

 

[lumenharold]

Perhaps you are thinking of the "two way" mirrors as seen on TV? They are called Mirropane and are made by Pilkington. They are not fully reflective and they do not pass all the light from the back side. Since you didn't specify wavelength or application I'll assume visible light and for viewing. Other than that, what IRStuff said....

http://www.pilkington.com/applicati...fit/specialapplications/mirropane/default.htm

Harold
SW2008 SP3.0 OPW2008 SP0.1 Win XP Pro 2002 SP2
Dell 690, Xeon 5160 @3.00GHz, 3.25GB RAM
nVidia Quadro FX4600

http://www.lumenflow.com

 

[rnickmoor]

This is usually done using a polarization-specific thin film mirror (TFP). Light from one direction has its polarization rotated via half-wave mirror (or quarter-wave if you're worried about transmission and then reflection), pockels cell, etc and is reflected by the mirror. Light from the other direction is allowed to transmit through the filter. In this way, you're setting up a reflecting optical isolator. Of course, this requires that the incoming light be polarized.

There are different methods of creating optical isolators. Do some research on optical isolators and you should be able to find one that best suits your light source and system.