The development of low-light night vision devices and the characteristics of each generation

Low-light night vision devices were invented in 1955. At that time, it was discovered that a photocathode made of the alkali metal antimony, potassium, sodium, and cesium could emit electrons when illuminated by weak night skylight, and was suitable for use in passive night vision devices. It has now developed into the third generation of products.

The first generation of low-light night vision device is a cascade image intensifier night vision device, the core part of which is the low-light tube. The low-light tube is similar to an infrared variable tube, but the photocathode uses an alkali metal antimony, potassium, sodium, and cesium, which is sensitive to visible light.

The second generation low-light night vision device is a micro-channel plate image intensifier night vision device. Compared with the first generation night vision device, it is small in size and light in weight, is not afraid of interference from strong light, and is suitable for use in flame and flash environments.

The third generation low-light night vision device starts from improving the semiconductor material of the photocathode, making it sensitive to both low light and infrared. It unifies the infrared night vision device and the low-light night vision device in one instrument, which can be used on clear days and nights. The low-light night vision device functions as an active infrared night vision device by emitting infrared rays at night in rainy and foggy days, and the range is farther than that of the second generation.

Low-light night vision devices can be used to detect the terrain, enemy firepower, and activities of forward positions at night. They can also be installed on individual light weapons and artillery as night sights. They can also be installed on mobile weapons for concealed driving observation at night. For road use, it can be installed on ships or submarines to monitor water surface conditions and attack enemies. It is widely used for border defense, post surveillance and to prevent sneak attacks. Under star and moonlight conditions, people 800 meters away and vehicles 1,500 meters away can be observed, and can be identified within 1,000 meters. However, it is completely ineffective in total darkness and cannot work normally in rainy and foggy days.

At night, night vision reconnaissance is achieved in an environment of low light (moonlight, starlight, and atmospheric glow are collectively referred to as night skylight). These cannot be sensed and distinguished by the human eye, but night vision equipment is used to enhance the low light to achieve night vision. Convert low light into electrical signals, and then convert them into light signals visible to human eyes through the luminous body. Currently, mainstream night vision equipment includes active infrared night vision devices, low-light night vision devices, low-light TVs and thermal imaging cameras.

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