They already use fiber-optic borescopes with no electronics on the lens side to create distance from electronics when their targets do sweeps.
You can also have opto-mechanical listening devices where the electronics are 100 m away. There is a vibrating membrane at one end, and a laser through the fiber reads the vibrations.
You can also have opto-mechanical listening devices where the electronics are 100 m away. There is a vibrating membrane at one end, and a laser through the fiber reads the vibrations.