Underwater Li-Fi to be used by the Navy

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The U.S. Navy has funded a research program to delve into the development of Li-Fi, a method of communication via LED lights. Li-Fi could potentially be the answer to society’s increasingly progressive data needs.

Instead of using generic radio waves to transmit Wi-Fi signals, this system takes a different approach. Li-Fi devices have a system of blinking lights that are used for transmitting data. These rapidly changing LED lights flash a mile-a-minute to enable data to be transferred over a Morse code-esque system of blinks. The LED flashes emit lights that correspond with a computer language comprised of zeros and ones. The lights' emissions are then lodged in a gadget that computes and translates the signal into real-time data. As the flashes blink faster and faster, data is able to be transmitted more quickly. It’s interesting how the flashes are invisible to the naked human eye; the lights’ flashes are so fast, that they’re impossible to see. 

The specific uses for Li-Fi are infinite. For example, the Navy wants to employ the use of Li-Fi to enhance submarine communication systems. They currently use a slow and antiquated system for underwater communication that does not quite jibe well with the poor acoustics that lie underwater. Radio waves also do not travel efficiently underwater. For use in petrochemical plants or on airplanes, Li-Fi emissions would be a great option, since Wi-Fi tends to interfere with onboard electronics.

The future applications that the government has in mind for Li-Fi could serve a much more vast purpose than just for underwater, airplane, and chemical plant usage. Currently, the Federal Communications Commission has explicated cautions of crowding in wireless communications because the radio frequency spectrum is beginning to get way too full. The implementation of Li-Fi could clear out the spectrum of radio frequency. Since the spectrum of light is 10,000 times larger than the spectrum of radio frequency, there is more flexibility for the transmission of data across many channels. Interestingly enough, the light doesn’t have any effect on radio waves, allowing Wi-Fi and Li-Fi to respectively cohabitate. Electronics could even eventually change back and forth between Wi-Fi and Li-Fi.

Researchers at the University of Edinburgh have been intensely testing Li-Fi. Through a series of trials, Li-Fi has accomplished extremely high speeds, reaching 3.5 gigabits per second over 5 centimeters at its highest point. So far, the fastest Wi-Fi speed has been recorded as 100 gigabits per second. Li-Fi demonstrates great potential.

The hyperbolic metamaterials that are being tested for use retain exclusive properties. This is because they function at a smaller scale than 400 to 700 nanometers, the wavelength of visible light. The process when electrons move within a material, called plasmonic resonance, is created when light hits an object. The plasmonic resonance is attached to the fluorescent emissions, that when increased, can trigger brighter lights with faster blinking speeds. The developers still need to integrate the metamaterials into the LEDs for proper functionality.  

Story via Gizmodo