Visible light at night is very weak, but infrared rays, which are invisible to the human eye, are abundant. Infrared vision devices can help people to observe, search, target and drive vehicles at night. Although people discovered infrared light very early, the development of infrared remote sensing technology is very slow due to the limitation of infrared components. It was not until 1940 that Germany developed lead sulfide and several infrared transmitting materials that the birth of infrared remote sensing instruments became possible. Since then, Germany has first developed several infrared detection instruments such as active infrared night vision devices, but none of them were actually used in World War II.

 

Almost at the same time, the United States was also developing infrared night vision devices. Although the test was successful later than Germany, it was the first to put it into practical application. In the summer of 1945, the U.S. military landed and attacked Okinawa Island. The Japanese army hidden in the caves took advantage of the complicated terrain and came out at night to attack the U.S. military. So the U.S. military urgently transported a batch of newly manufactured infrared night vision devices to Okinawa, and mounted the guns with infrared night vision devices near the cave. The Japanese army inside the cave didn't know the reason, and continued to charge out, and lost their lives in a confused way. When the infrared night vision device first entered the battlefield, it played an important role in clearing the stubborn Japanese army on Okinawa Island.

 

The active infrared night vision device has the characteristics of clear imaging and simple production, but its fatal weakness is that the infrared light of the infrared searchlight will be detected by the enemy's infrared detection device. In the 1960s, the United States first developed a passive thermal imager, which does not emit infrared light, is not easy to be discovered by the enemy, and has the ability to observe through fog and rain.

 

From April to June 1982, the Malvinas Islands War broke out between the United Kingdom and Argentina. In the middle of the night on April 13, the British army attacked Port Stanley, the largest stronghold of the Chengjun army. A minefield laid by 3,000 British troops suddenly appeared in front of the Afghan defense line. All guns and artillery in the UK are equipped with infrared night vision devices, which can clearly detect the targets of the Afghan army in the dark. However, the Arab army lacked night vision goggles and could not detect the British army, only passively beaten. Under the accurate attack of the British firepower, the Afghan army could not support it, and the British army took the opportunity to launch a charge. By dawn, the British had occupied several major commanding heights on the Afghan defense line, and the Afghan army was completely under British fire control. At 9 p.m. on June 14, 14,000 Afghan troops had to surrender to the British. The British Army's lead in infrared night vision equipment has won a disparity battle.

 

In the 1991 Gulf War, on the battlefield filled with sand and gunpowder, because the US military was equipped with advanced infrared night vision equipment, it was able to detect the other side before the Iraqi army's tanks and fired. The Iraqi army learned that the enemy was ahead only from the muzzle fire when the American tanks fired. It can be seen that infrared night vision equipment plays an important role in modern warfare.