Until recently, such a sensor — a thousand times more sensitive than today's navigation-grade devices — would have required a moving truck to transport.
However, advancements are significantly reducing the size and cost of this technology. For the first time, researchers from Sandia National Laboratories have used silicon photonic microchip components to perform a quantum sensing technique known as atom interferometry, an ultra-precise method of measuring acceleration.
This represents the latest milestone towards developing a quantum compass for navigation when GPS signals are unavailable.
The team published its findings and introduced a new high-performance silicon photonic modulator — a device that controls light on a microchip — as the cover story in the journal Science Advances. The new modulator is the centrepiece of a laser system on a microchip, rugged enough to withstand heavy vibrations. It would replace a conventional laser system the size of a refrigerator.
In addition to size, cost has been a significant barrier to deploying quantum navigation devices. Every atom interferometer requires a laser system, and laser systems need modulators.
Sandia scientist Jongmin Lee said: "Just one full-size single-sideband modulator, a commercially available one, is more than $10,000,.
Miniaturising bulky, expensive components into silicon photonic chips helps reduce these costs.
"We can make hundreds of modulators on a single 8-inch wafer and even more on a 12-inch wafer," Kodigala said. And since they can be manufactured using the same process as virtually all computer chips,
"This sophisticated four-channel component, including additional custom features, can be mass-produced at a much lower cost than today's commercial alternatives, enabling the production of quantum inertial measurement units at a reduced cost," Lee said.
The team explores other applications beyond navigation as the technology approaches field deployment. Researchers are investigating whether it could help locate underground cavities and resources by detecting the minute changes these make to Earth's gravitational force.
They also see potential for the optical components they invented, including the modulator, in LIDAR, quantum computing, and optical communications.