China is making great efforts to detect U.S. submarines.
Scientists at a Chinese research institute say they developed an airborne laser that might eventually detect hostile subs even at great depths.
Meanwhile, scientists at another institute also claim to have developed a magnetic detection device that might spot subs.
Researchers at the Shanghai Institute of Optics and Fine Mechanics say they have tested lasers that can detect objects more than 160 meters (525 feet) beneath the water, or twice as deep as current equipment.
“The Shanghai team used a beam generated by green and blue lasers,” according to the South China Morning Post. “As light – even laser, a pure, coherent form of light – scatters faster in water than in air, the beam must be very powerful to go deep. Laser devices generate an energized beam of light of a single color, or frequency. Green and blue beams can penetrate water with relative ease.
“Chen’s team also developed a highly sensitive detector that can pick up a single photon reflected from a target, allowing the device to detect bright objects close to the surface as well as targets hidden in the deep.”
A team at the Wuhan Institute of Physics and Mathematics say they have devised a magnetic detection sensor that can fit into a capsule the size of a bean. “The device can pick up signals as weak as 20 femtotesla, or about one-fifth the strength of the magnetic field generated by a human brain,” explained the South China Morning Post.
“Although other devices known as magnetic anomaly detectors are much more sensitive, they are bulkier and can only be mounted on planes or helicopters,” the Post added. “Magnetic anomaly detectors used in anti-submarine warfare must operate at temperatures near absolute zero and require lasers, power supplies and gas chambers to achieve high sensitivity.”
In 2018, Chinese scientists said they were developing a laser-equipped satellite that could detect submarines. The idea is to use laser beams of various colors that can detect disturbances in the water caused by a moving submarine.