How Does Night Vision Work?
An image intensifier tube amplifies light on the lower end of the infrared light spectrum to illuminate images.
Objects detectable by the unaided eye typically reflect light on the visible light spectrum. In the dark, these objects only reflect light on the infrared spectrum, the range of wavelengths just below visible light, making them imperceptible to observers.
Light is emitted in the form of photons, packets of energy released when excited electrons return to their normal ground state. Image enhancement employs this principle to intensify infrared light by converting photons to electrons and back again.
In night vision gear, an optical lens gathers infrared light and sends it into an image intensifier tube, where light energy is converted into electrons. These pass through a microchannel plate, causing a chain reaction that releases thousands of others.
At the end of the tube, the electrons hit a screen coated with compounds called phosphors. These electrons maintain their position relative to the channel through which they passed to provide a perfect replica of the image. The energy of the electrons causes the phosphors to reach an excited state and release photons, creating the characteristic green image of night