Enhancing the world's most precise clock

The cryogenic sapphire oscillator (Sapphire Clock), said to be the world’s most precise clock, allows users to take ultrahigh-precision measurements to improve the performance of electronic systems. Now, the clock has been enhanced by researchers from the University of Adelaide to achieve near attosecond capability.

Increased time precision is an integral part of radar technology and quantum computing, which have previously relied on the stability of quartz oscillators and atomic clocks. However, while atomic clocks are the gold standard in time-keeping for long-term stability, electronic systems need short-term stability over a second to control today’s devices. The Sapphire Clock has a short-term stability of around 1x10^-15 — equivalent to only losing or gaining one second every 40 million years — making it 100 times better than commercial atomic clocks.

The 100 x 40 x 40 cm clock has a 5 cm cylinder-shaped crystal that is cooled to -269°C. Microwave radiation is constantly propagating around the crystal with a natural resonance. The clock uses small probes to pick up this faint resonance and amplifies it back to produce a pure frequency with near attosecond performance. It is this frequency that is used to maintain a steady oscillator signal.

“An atomic clock uses an electronic transition between two energy levels of an atom as a frequency standard,” explained lead researcher Associate Professor Martin O’Connor.

“The atomic clock is what is commonly used in GPS satellites and in other quantum computing and astronomy applications, but our clock is set to disrupt these current applications.”

The development group is currently in the process of modifying the device to meet the needs of industries including defence, quantum computing and radioastronomy. Associate Professor O’Connor noted, “We can now tailor the oscillator to the application of our customers by reducing its size, weight and power consumption, but it is still beyond current electronic systems.”

The lab-based version already has an existing customer in the Defence Science and Technology Group (DST Group) in Adelaide, but Associate Professor O’Connor said the research group is looking for more clients and is in discussion with a number of different industry groups.

“Our technology is so far ahead of the game, it is now the time to transfer it into a commercial product,” he said.

The research group is currently taking part in CSIRO’s On Prime pre-accelerator program, which helps teams identify customer segments and build business plans. Commercial versions of the Sapphire Clock will be made available in 2017.

This article is a modified version of a news item published by The Lead South Australia under Creative Commons.

Image caption: The sapphire crystal on display at the University of Adelaide.