A company in Japan made optical mics a few decades ago. The Japanese radio (education dept) had these on test for years. Expensive stuff. No problems with electrical/magnetic noise. Very small pickup, optical fiber.
Afaict, these are still made for hostile industrial environments.
Now if I could only remember the companies name...
While looking for that company, I came across a 1999 press release from Kenwood. Apparently, they were looking at optical mics too:
https://www.kenwood.com/jp/en/news/microphone.html
One of the leading companies was Phone-Or Ltd. Israeli defense industry.
I think the Japanese company commercially evolved into this:
https://www.optoacoustics.com/industrial/optical-microphones?gad_source=1
Afaict, these are still made for hostile industrial environments.
Now if I could only remember the companies name...
While looking for that company, I came across a 1999 press release from Kenwood. Apparently, they were looking at optical mics too:
https://www.kenwood.com/jp/en/news/microphone.html
One of the leading companies was Phone-Or Ltd. Israeli defense industry.
I think the Japanese company commercially evolved into this:
https://www.optoacoustics.com/industrial/optical-microphones?gad_source=1
