This magnifies the amount of received photons from various natural sources such as starlight or moonlight. Examples of such technologies include night glasses and low light cameras. In the military context, Image Intensifiers are often called “Low Light TV” since the video signal is often transmitted to a display within a control center. These are usually integrated into a sensor containing both visible and IR detectors and the streams are used independently or in fused mode, depending on the mission at hand’s requirements.^[11]

The image intensifier is a vacuum-tube based device (photomultiplier tube) that can generate an image from a very small number of photons (such as the light from stars in the sky) so that a dimly lit scene can be viewed in real-time by the naked eye via visual output, or stored as data for later analysis. While many believe the light is “amplified,” it is not. When light strikes a charged photocathode plate, electrons are emitted through a vacuum tube and strike the microchannel plate. This causes the image screen to illuminate with a picture in the same pattern as the light that strikes the photocathode and on a wavelength the human eye can see. This is much like a CRT television, but instead of color guns the photocathode does the emitting.

The image is said to become “intensified” because the output visible light is brighter than the incoming light, and this effect directly relates to the difference in passive and active night vision goggles. Currently, the most popular image intensifier is the drop-in ANVIS module, though many other models and sizes are available at the market. Recently, the US Navy announced intentions to procure a dual-color variant of the ANVIS for use in the cockpit of airborne platforms.^[