Types of Night Vision

My generation

The four categories of night vision equipment are often called "generations," and each generation uses an image-intensifier tube of a different grade, as well as more advanced engineering technology. The very first night vision devices, called Generation 0, were produced during World War II and used active infrared, meaning infrared illuminators created a beam of infrared light that would bounce back to the night vision device and produce illuminated images. The downside of such night vision devices, however, was that hostile forces could see the bright red images from the devices.

The second generation of night vision equipment, Generation 1, uses passive infrared technology. In a Generation 1 night vision device, image tubes collect whatever ambient light is available and amplify it. If no ambient light is present, the device will use infrared illuminators.

Frequently refereed to as "military-grade" or "mil-spec" equipment, Generation 2 night vision devices are significantly more expensive than Generation 1 devices but offer better image resolution and brighter green images through the phosphor screen. The high-performance micro-channel plate in a Generation 2 device (which both speeds up electrons and increases the number of electrons in the vacuum tube) allows the user to view objects in very low light without the assistance of infrared illuminators.

Finally, Generation 3 night vision equipment, building on Generation 2 technology, offers the best possible image resolution and brightness due to the use of gallium arsenate, which has a highly saturated electronic velocity and is very efficient at converting photons to electrons.