Researchers from the University of Sydney's Australian Institute for Nanoscale Science and Technology have made a breakthrough by achieving radio frequency signal control at sub-nanosecond time scales on a chip-scale optical device.
This new research could unlock the bandwidth bottleneck faced by wireless networks worldwide. The project is being researched at the headquarters of the Australian Institute for Nanoscale Science and Technology (AINST), in Sydney. This is Nanoscience Hub was completed in 2016 and cost $150 Million.
Today, there are 10 billion mobile devices connected to the wireless network (reported by Cisco last year), each one requiring bandwidth and capacity. By creating very fast tunable delay lines on chip, you can eventually provide broader bandwidth instantaneously to more users. The ability of rapidly controlling RF signal is a crucial performance for applications in both our daily life and defence.
For example, to reduce power consumption and maximize reception range for future mobile communications, RF signals need to achieve directional and fast distributions to different cellular users from information centres, instead of spreading signal energy in all directions.
The lack of the high tuning speed in current RF electronic techniques used in modern communications and defence, has motivated the development of solutions on a compact optical platform. These optical counterparts have been typically limited in performance by a low tuning speed on the order of milliseconds (1/1000 of a second) offered by on-chip heaters, with side effects of fabrication complexity and power consumption.
To circumvent these problems, researchers developed a simple technique based on optical control with a response time faster than one nanosecond: a billionth of a second - this is a million times faster than thermal heating.
CUDOS Director and co-author Professor Benjamin Eggleton, who also heads the Nanoscale Photonics Circuits AINST flagship, said the technology would not only be important for building more efficient radars to detect enemy attacks but would also make significant improvements for everyone. Such a system will be crucial not only to safeguard defence capabilities, it will also help connect more devices to the wireless network. This includes the internet of things, 5G communications, smart home and smart cities.
Silicon photonics, the technology that underpins this advance, is progressing very quickly, finding applications in datacentres right now. Scientists expect the applications of this work will happen within a decade in order to provide a solution to the wireless bandwdith problem. They are currently working on the more advanced silicon devices that are highly integrated and can be used in small mobile devices.
By optically varying the control signal at gigahertz speeds, the time delay of the RF signal can be amplified and switched at the same speed.
Researchers achieved this on an integrated photonic chip, paving the way towards ultrafast and reconfigurable on-chip RF systems with unmatched advantages in compactness, low power consumption, low fabrication complexity, flexibility and compatibility with existing RF functionalities. Click here to read the published paper.
