Communication through the modulation of electromagnetic radiation has become a foundational technique in modern technology. In this paper we discuss a modern day method of eavesdropping based upon the modulation of laser light reflected from a window pane. A simple and affordable classroom demonstration of a “laser microphone” is described.

Topics
Microphones, Electromagnetic radiation, Educational aids
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© 2006 American Association of Physics Teachers.
2006
American Association of Physics Teachers
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