[sdiy] OT: Laser Microphones?

[Grant Richter]

> Does anyone know of any internet links regarding laser-based microphones,
> other than those designed for surveillance? It just seems to me that
> someone would have tried to make a microphone that used a laser, and use it
> for "normal" high fidelity recording purposes. Unfortunately, all the
> information I can find is related to bouncing a laser off someone's window,
> to listen to conversations on the other side of the window.

Interesting note: I saw a PBS program on master spies, among whom was Leon
Theremin. According to the program, Lenin ordered Theremin to do a musical
tour of the United States in order to copy patents at the patent office. To
Lenin, the invention of the musical instrument was a convenient and
effective cover story. But there is no doubt Theremin genuinely loved music
and was proud of his invention of the "etherophone". He was a scientist
forced into spying by the KGB.

When Theremin was recalled by the KGB and put into a technical Gulag, he
went on to invent two of the most clever spy gadgets ever declassified ;^)

The first was the passive cavity resonator in the wooden seal at the United
States embassy (very famous). The second was the idea of using light
reflected off of a window to form a passive listening bug. The idea was
invented before the laser, originally using beams of infrared radiation.

While we call him a spy, the Russians call him a patriot, though he was
never rewarded in his lifetime.

No matter, the technical genius of the man is fantastic, and we're still
finding new applications for his work today.