[sdiy] OT: Laser Microphones?

[houshu at muj.biglobe.ne.jp]

Hello Glen,

I'd suggest you to check out Phone-Or site and their patents.

  http://www.phone-or.com/

As far as I know, its dynamic range is not sufficiently large 
for high fidelity recording.  Current products (and most of 
prototypes) are only for telephone quality sound.

Sam Hoshuyama

> 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.
> 
> Couldn't the beam be bounced off a reflective membrane mounted very close
> to the laser, and then analyze the reflected beam, to record sounds in the
> same room as the laser? I'm wondering what advantages there might be to
> laser pickup of the membrane's vibrations, compared to magnetic (dynamic),
> or electrostatic (condenser) pickup of the membrane's vibrations. 
> 
> It shouldn't be as prone to pickup of stray magnetic fields as a dynamic
> mic, and therefore should work well around CRT's and other magnetic
> devices. I think it might also offer the potential to have less background
> hiss than a typical condenser, and have a potentially large dynamic range.
> 
> Does anyone know of any attempts to create such a microphone?
> 
> later,
> Glen