The U.S. government is to patent a new quantum photonic imaging device that will detect anything underwater while providing unprecedented stealth for its submarines.
Currently, submarines travelling through Arctic waters have to use gyroscopes and accelerometers to measure the motion and rotation of the vehicle in order to estimate the current position, orientation and velocity of another submarine – as GPS signals are unable to reach underwater.
They could use an active sonar array detection system in order to spot ice canopies underwater to prevent accidental collisions, but the drawback of using this is that it reveals the position of the submarine to any enemies underwater. However, in areas of high latitude such as the North Pole, gyroscopes and compasses become unreliable due to proximity to the geomagnetic North Pole and the Earth’s rotation axis, so the Navy has no choice but to use the active sonar array.
To solve this problem, a new patent application filed by the US government describes a quantum photonic imaging device that uses quantum entanglement to silently detect and identify targets. The device generates a pair of entangled photons, and one of the photons, known as the “signal photon”, is transmitted into the unknown.
The signal photon is basically a probe, and when it comes into contact with an obstacle, the target reflects the radiation from the probe photon, which is picked up by a biologically-inspired quantum photo sensor, which contains the other photon in the pair, known as the “ancilla proton”.
If the correlation between the two photons is high, then the submarine knows that an object is present.
But unlike active sonar, the reflected radiation travels at levels that are below noise levels, so that the photons’ activities are completely indistinguishable from other noise so it cannot be detected at all until it is correlated with the correct code sequence.
In practice, the submarine wouldbasically send out numerous entangled proton pairs, and they would essentially highlight the shape and dimensions of the man-made or natural obstacle.
The video below, created by PatentYogi, provides a handy visualisation that makes it easier to understand how the device would work:
PatentYogi YouTube video: Quantum Entanglement to provide unprecedented level of stealth for military applications.