night vision goggles?

Question

Do they convert infared photons to optical or optical to infared?

Answer 1

There are three different types of night vision equipment.

1. During WW2 near IR equipment was used. These use an IR only spotlight and a receiver that converts the near IR image to an optical image displayed on a screen.

2. In the 1960s night vision equipment was used that used light amplification technology. These amplify low levels of "visible" or near IR light and display an image on a screen.

3. In resent decades thermal imaging equipment has been created. These receive far infrared (heat) light and convert it to an image that is displayed on a screen.

Note that photons are not "converted" in these devices; the original light coming into the device is used to modulate a power source in the device to create an image with other photons.

Answer 2

Infrared to optical... but only a small portion of infrared most of it is just small amounts of light......