Twisted Light to boost Internet speed

Fiber optics are used for the communication of data at the speed of light but the amount of data that can be transmitted is limited by how much information one can encode into the light wave traveling through the optic fiber.

This technology uses various properties of light to encode information, including polarization, color, brightness and direction of propagation. However, to shove more information through optic fiber, we need to use other features of light without disrupting the currently used properties.Such a feature has potential to help boost the bandwidth of optic fiber technology, including our internet speeds.

Twist to turn

If the light wave traveling through the optic fiber is twisted helically—like a spring—then it has angular momentum, which is a measure of its momentum when it rotates around a point.

However, to use angular momentum to decode the information from the optic fiber we need a material with tiny nanoscale helical structures that could detect the twisted light. American Association for the Advancement of Science has an answer for this. According to a research by the association, we can control the angular momentum of light at a nanoscale using an integrated photonic chip, a chip with a series of elaborate nano-apertures and nano-grooves that allow for the on-chip manipulation of twisted light.

The nanophotonic chip magnified 2,000 times. Each indentation on the image is a single unit of the chip, like a single pixel in a display panel, made up of semi-circle nano-grooves and nano-apertures engraved in a metallic film.

Because of the helical design of these tiny apertures and grooves there is no need for any other bulky interference-based optics to detect the angular momentum signals which mean if you are sending an optical data signal to a photonic chip, which is a microchip that uses light instead of electrons, then it is important to know where the data is going, otherwise information might get lost.

The Nanophotonic chip can precisely guide angular momentum data signals without losing the information they carry. Importantly this chip can process the angular momentum information of many different signals at the same time. This means we can potentially achieve an ultra-wide bandwidth, with a six-orders magnitude of increased data access compared to current technology.

New Horizons

Nano-fabrication technology isn’t new and has been witnessing rapid development which means there shouldn’t be any technical challenge to the mass production of this chip today.

The breakthrough opens new horizons for employing light for chip-scale information generation, transmission and retrieval of images, videos, sounds and so on.It could be used in applications such as data transmission, ultra-high definition displays, ultra-high capacity optical communications and ultra-secure optical encryption. For example, the communication speed on the National Broadband Network can be boosted through the parallel processing of the angular momentum.

The Nanophotonic chip consists of an array of individually-controlled single units, and each single unit is capable of independently processing the angular momentum information which can lead to parallel processing of optical information.

Also, a large number of optical fibers in one fiber bundle can be processed through the chip in parallel, which means the processing speed can be significantly increased by considering how large the array is. For example, taking 100 by 100 of such units in the array for the chip, the speed could be boosted by four orders of magnitude.

This ‘twist’ of science will one day lead to significantly faster internet speeds along with a host of other useful applications.

Adapted from theconversation.com