As you know, radio waves propagate poorly underwater, which makes it hard to link divers and submarines when sending information to the surface.
In 2018, the graduate student of University of science and technology named after king Abdullah (KAUST) Abdullah al-Halafi and his supervisor Basim of Shihada developed a system of underwater wireless optical communication (UMOC) that allows you to transmit HD video in the aquatic environment. Based on this technology have created a new system called Aqua-Fi.
How it works. For example, the diver begins to transmit a photo or video from your smartphone, placed in a protective case. Initially, it broadcast as radio waves to a small device located in close proximity to the tanks.
Then, the microcomputer this device converts the information into a series of light pulses. Then encoded into a binary code pulses ubavlyaetsya on the receiver built-in 520-nm lasers or an array of green LEDs.
The difference is that the LEDs transmit information over short distances using low power, while the laser can relay them on, but consumes significantly more energy.
Reaching the surface, the coded pulses fall on the detector, mounted at the bottom of the ship, and then converted into the usual photo or video through a connected computer. Further files can be uploaded to the Internet via satellite.
Earlier technology Aqua-Fi has been tested only for the exchange of video files between two PCs placed in static water environment at a distance of about 5 meters. However, to use the system in everyday settings, has yet to solve a number of problems, e.g. to adapt it to the light scattering effect of moving water, which may require a spherical receiving equipment capable of receiving pulses of light from all directions.