Laser microphone


Laser microphone

A laser microphone is a surveillance device that uses a laser beam to detect sound vibrations in a distant object. The object is typically inside a room where a conversation is taking place, and can be anything that can vibrate (for example, a picture on a wall) in response to the pressure waves created by noises present in the room. The object preferably has a smooth surface. The laser beam is directed into the room through a window, reflects off the object and returns to a receiver that converts the beam to an audio signal. The beam may also be bounced off the window itself. The minute differences in the distance traveled by the light as it reflects from the vibrating object are detected interferometrically. The interferometer converts the variations to intensity variations, and electronics are used to convert these variations to signals that can be converted back to sound.

This technology can be used to eavesdrop with minimal chance of exposure. However, countermeasures exist in the form of specialized light sensors that can detect the light from the beam. Rippled glass can be used as a defense, as it provides a poor surface for a laser microphone.

External links

* [http://www.williamson-labs.com/laser-mic.htm "Laser Microphones"] , Williamson Labs


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Microphone — For the indie film, see Microphone (film). Microphones redirects here. For the indie band, see The Microphones. A …   Wikipedia

  • Laser-Mikrofon — Ein Lasermikrofon ist ein Tonabnehmer, der mittels Laserstrahlen Festkörperschwingungen von anvisierten Objekten in elektrische Spannungsimpulse umwandelt. Inhaltsverzeichnis 1 Funktionsweise 2 Anwendung 3 Abwehr 4 Weblinks // …   Deutsch Wikipedia

  • Measuring instrument — Captain Nemo and Professor Aronnax contemplating measuring instruments in Twenty Thousand Leagues Under the Sea …   Wikipedia

  • Sam Fisher — General VG character name = Samuel Fisher caption = series = Tom Clancy s Splinter Cell firstgame = Tom Clancy s Splinter Cell creator = artist = voiceactor = Michael Ironside (English) Tesshō Genda (Japanese) Daniel Beretta (French) Martin… …   Wikipedia

  • Lasermikrofon — Ein Lasermikrofon ist ein Tonabnehmer, der mittels Laserstrahlen Festkörperschwingungen von anvisierten Objekten in elektrische Spannungsimpulse umwandelt. Inhaltsverzeichnis 1 Funktionsweise 2 Anwendung 3 Abwehr 4 …   Deutsch Wikipedia

  • Fiber optic sensor — A fiber optic sensor is a sensor that uses optical fiber either as the sensing element ( intrinsic sensors ), or as a means of relaying signals from a remote sensor to the electronics that process the signals ( extrinsic sensors ). Fibers have… …   Wikipedia

  • Gramophone record — A 12 inch (30 cm) 33⅓ rpm record (left), a 7 inch 45 rpm record (right), and a CD (above) A gramophone record, commonly known as a phonograph record (in American English), vinyl record (in reference to vinyl, the material most commonly used after …   Wikipedia

  • Razer USA — This article is about the computer peripherals manufacturer named Razer. For other meanings see Razer (disambiguation). Razer USA Ltd Type Private Industry Comput …   Wikipedia

  • List of Celebrity Deathmatch episodes — This is the list of all the episodes and fights in the claymation series Celebrity Deathmatch. Bolded characters s names are the winners in a fight. Contents 1 Pilot episodes (January 1 25, 1998) …   Wikipedia

  • Mars Polar Lander — Artist depiction of Mars Polar Lander on Mars. Operator NASA / JPL Major contractors Martin Marietta …   Wikipedia


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.