Night Vision Technology, as the name suggests, is the expertise that makes us capable to see in the night without using any external light source such as a torch or a lamp. Highly advanced light sensitive cameras are used in this technology that produce clear visible images at night which the naked eye can’t do. Since the human eye is quite sensitive to green colour which falls in the middle of the spectrum, these cameras have green phosphor which gives the green colour to the Night Vision Cameras.
Night Vision technology has been under research since Pre-World War II. However, a defined shape came post World War II, i.e., in early 1950s. This is when Generation-0 for Night Vision was developed. The basic principle followed was using the light of the InfraRed region for the purpose of viewing.
Generation-1 night vision gadgets didn’t have any source of light unlike the previous generation, as they were well advanced to use the little amount of light present in the environment. Even though less bulky and more efficient, these optical sensors needed moonlight to function properly. The images produced were ambiguous at the edges of the lens. But those who were equipped with this technology got a straight edge over the rivals as don’t had it found no alternatives than to protect them or use illuminations all night long. The improvements in the image intensifier tube or the ITT were mainly responsible for evolution of new generations in night vision technology.
Generation-2 came up during the 70s when some remarkable achievements in physics and optical phenomena could be actually transformed into other forms. Devices in this generation were loaded with image intensifiers which were basically photo cathodes that came along with micro channel plates or MCPs. These MCPs detect electrons whose frequency doesn’t come in the visible region of the light spectrum. This fairly solved the problem of unambiguous images as well as gave a well intensified and resolved image which restricted the life of the tube to be around 1000 hours.
In Generation-3, arrival of Gallium Arsenide as photocathode was seen. This, along with more advanced ion barrier film, increased the amount to which the image could be intensified by MCP and the intensifier tube’s life also increased by 1000 hours. Generation-3 devices are widely used and serve as the prime night vision devices for the US Army.
The gating technologies for power input stand as the benchmarks for Generation-4 of night vision technology as they confiscate the ion barriers and give best resolved form of the image. Amazingly efficient in the low light, Generation-4 devices are still considered in Generation-3 by the US Army.
Filed Under: What Is