RMIT University’s Distinguished Professor Arnan Mitchell and University of Adelaide’s Dr Andy Boes led a team of global experts to review lithium niobate’s capabilities and potential applications in the journal Science.
The international team, including scientists from China and the United States, is working with industry to make navigation systems that are planned to help rovers drive on the Moon later this decade.
As it is impossible to use global positioning system technology on the Moon, navigation systems in lunar rovers will need to use an alternative system, which is where the team’s innovation comes in.
By detecting tiny changes in laser light, the lithium-niobate chip could be used to measure movement without needing external signals, Prof Mitchell said.
“This is not science fiction — this artificial crystal is being used to develop a range of exciting applications. And competition to harness the potential of this versatile technology is heating up,” he said.
What is lithium niobate?
Dr Boes said lithium niobate was an artificial crystal that was first discovered in 1949 but was “back in vogue”.
“Lithium niobate has new uses in the field of photonics — the science and technology of light — because unlike other materials it can generate and manipulate electro-magnetic waves across the full spectrum of light, from microwave to UV frequencies,” he said.
“Silicon was the material of choice for electronic circuits, but its limitations have become increasingly apparent in photonics.
“Lithium niobate has come back into vogue because of its superior capabilities, and advances in manufacturing mean that it is now readily available as thin films on semiconductor wafers.”
Dr Boes said a layer of lithium niobate about 1000 times thinner than a human hair was placed on a semiconductor wafer.
“Photonic circuits are printed into the lithium niobate layer, which are tailored according to the chip’s intended use. A fingernail-sized chip may contain hundreds of different circuits.”
Potential applications closer to home
This technology can also be used to remotely detect the ripeness of fruit.
“Gas emitted by ripe fruit is absorbed by light in the mid-infrared part of the spectrum,” Prof Mitchell said.
“A drone hovering in an orchard would transmit light to another which would sense the degree to which the light is absorbed and when fruit is ready for harvesting.
“Our microchip technology is much smaller, cheaper and more accurate than current technology and can be used with very small drones that won’t damage fruit trees.”
Next steps
Prof Mitchell said Australia could become a global hub for manufacturing integrated photonic chips from lithium niobate that would have a major impact on applications in technology that use every part of the spectrum of light.
“We have the technology to manufacture these chips in Australia and we have the industries that will use them,” he said.
“Photonic chips can now transform industries well beyond optical fibre communications.”
