Researchers at the ANU-led ARC Centre of Excellence for Transformative Meta-Optical Systems (TMOS) are producing the light-based technologies that are needed to meet the evolving demands of Industry 4.0.

TMOS researchers are developing the devices that are expected to unlock widespread use of holographic displays, artificial vision, wearable medical devices, and ultra-fast WiFi whilst also laying the foundations for many more applications that are yet to be imagined.

The aim of TMOS is to develop ultrathin devices that create, manipulate, and detect light. These platforms are part of a movement towards meta-optical components that use nanofabricated structures to control light in ways that go beyond what is achievable by traditional approaches to photonics.

The team’s latest ANFF-enabled research, led by the group of Professor Andrey Sukhorukov, drives the development of novel meta-optical devices for quantum applications.

The specific design by PhD student Shaun Lang is tailored for manipulation of entangled photons. These paired particles can be used to deliver the potential of quantum computers and to transmit unbreakable messages across incredible distances.

The entanglement principle is a quantum phenomenon that sees pairs of particles such as photons becoming twinned so that any changes made to one partnered particle is exhibited by the other. Theoretically, this connection remains regardless of how far apart the particles are, even if they’re separated to opposite sides of the universe.

The project shows a way to change the polarisation of two photons simultaneously, which can accordingly modify the degree of quantum entanglement, an operation essential for a range of quantum protocols.

The research demonstrates a use of an array of structures called nanoresonators, which are features that measure 100 times smaller than a human hair. They resonate differently depending on the incoming light polarisation across a particular range of wavelengths.

Importantly, the optimisation of the arrangement and dimensions of the individual nanoresonators, which in combination form an ultrathin metasurface, allows the implementation of multiple controllable transformations of photon polarisations with a single device.

The metasurfaces were fabricated at ANFF-ACT using electron beam lithography and inductively coupled plasma etching, creating silicon nanostructure arrays with a thickness of 800 nm, optimised for operation around the 1,550 nm wavelength range which is compatible with the telecommunications industry. “The advanced equipment and dedicated staff at ANFF enable the fabrication with remarkable quality down to nanoscale,” said Dr Jihua Zhang, a postdoctoral fellow working on quantum metasurfaces.

“This topic is an important part of the research mission in TMOS. Through ANFF-ACT and other sister nodes, we aim to develop the science and technology of meta-optics into novel devices and translate them into practical applications such as holographic displays, wearable optical sensors, remote sensing and imaging,” said Prof. Dragomir Neshev, director of TMOS.