Laser Microphones?

I have heard of laser mics that the military, intelligence agencies etc.. use. In the game Spinter Cell you can use one to evesdrop on people insider. I couldn't really seem to find anything online other than this

www.williamson-labs.com...


from what I understand of it sound from peoples voices etc.. vibrates the window, and a laser can detect the vibrations on the glass from the outide and convert it back into a audio signal.

I was hoping that some ATS members that know more could share.



Are laser mics real? Do they work well? How far is their effective range? Are they only available to the military and intel agencies?

Thanks

Yes it’s real. The CIA building is a box inside a box to defeat this type of listening device. They also pump music or static noise in the void between the boxes so there is no chance a laser could pick-up a real conversation in the building. It’s cool technology though fairly old.

You can buy kits to build your own in the back of Boys Life (unless that is no longer possible thanks to our wonderful Homeland Security BS). The range is limited to the effective range of the laser, taking into account the target range as well as the return path.
The laser is pointed at the target solid (windows work best) and the vibrations in the beam are read and encoded back into an audible signal.
> the beam's reflection, that is. the 'listener' would be two stations, the laser itself and a collector described below.
It wouldn't be too terribly difficult to build your own.. you'd need a lot of really small photoresistors or a CCD matrix to pick up the minute vibrations in the beam, the rest is normal analog audio circuitry.

>> oh ok uhm is it obvious I didnt read the posted article? I really need to quit that... bad, bad geek, bad.



[edit on 7-5-2005 by apc]