Image Intensifier Tubes

The principle of action of Night Vision Devices is based on the transformation of the Photons reflected from the object to electrons, the subsequent multiplication of electrons and return transformation to the photons perceived by the human eye. To provide such transformation and strengthening of light a device named Image Intensifier Tube (IIT) is used.

     According to their designs, they belong to three generations:1,2+and 3.

First Generation IIT are now applied for amateur applications. All versions of these IIT have common design and as a rule, it works in condition of high light level that is formed either by moonlight or by IR illuminators. Luminance Gain in 1st Gen IIT is up to 100 times.

2 and 2+ gen IIT with Micro Channel Plate (MCP) inside vacuum tube became the result of the next step in the development to IIT.

MCP multiplies electrons produced by the photo cathode by several hundreds times, though MCP itself has small size. That made it possible to design high quality Night Vision Devices of a relatively small size. Not very high value of photosensitivity in IR spectrum can be referred to the disadvantages of this type of IIT.

At the present moment 3rd Generation IIT have the highest performance available. The use of the high-efficiency photocathode based on Gallium Arsenide (GaAs) differs 3rd gen tubes from the others. GaAs provides maximum photocathode sensitivity in the IR spectrum so that Night Vision Devices can be covertly used at very low light levels.