Nanostructured film boosts optical communications

Rainbows

Researchers from the RMIT School of Engineering have developed a nanostructured thin film that selectively filters light in order to increase the bandwidth and speed of optical communication systems.

This development would allow the use of existing optical fibres in next-generation networks that deliver the speeds needed to smoothly stream high-resolution videos and other data-heavy content to a larger number of users.

With the expansion of the Internet and the proliferation of smartphones and other connected devices, as well as the development of high-resolution, virtual reality and 3D content, the traffic streaming through data networks is dramatically increasing.

At the same time, optical component and circuit engineers find themselves simultaneously needing to meet requirements for increased performance and capacity, while reducing costs and size.

The limitations of current optical technologies means communication companies are finding it increasingly difficult to balance speed and cost, especially in the areas of optical data storage, digital imaging, displays, industrial optics, and optical communications.

The RMIT engineers, led by Dr Jiao Line, Vice Chancellor’s Research Fellow in the RMIT School of Engineering, hope their breakthrough will deliver the next-generation performance needed to overcome these barriers.

Dr Lin collaborated with researchers from the University of Melbourne, La Trobe University, Shenzhen University (China) and Nanyang Technological University (Singapore) to develop a nanostructured thin film that selectively filters light based on the polarisation of electromagnetic radiation.

The team used a technique to transmit the light down a very thin fibre of glass to the detector, which then converted the pulses of light into equivalent electrical pulses.

“In this way the data can be transmitted as light over great distance,” Dr Lin explained.

“Applying this nanostructured thin film onto photodiodes in optical communication systems will significantly increase the bandwidth of optical communication systems by as much as 100 percent.”

This breakthrough is significant as there are currently no commercially available solutions that specifically enable the filtering of light, based on its elliptically polarized state, that are easy to manufacture through lithography and are scalable for commercial purposes.

An added benefit is that the nanostructured thin film can be easily integrated with current optical communication systems, easing commercial roll-out.

The researchers have applied for a patent covering the technology, and will undertake further research and development to refine the technology and explore new applications.