An international research team has developed a prototype quantum radar that it says has the potential to detect objects invisible to conventional systems.

The radar is a hybrid system that uses quantum correlation between microwave and optical beams to detect objects of low reflectivity, such as cancer cells or aircraft with a stealth capability.

The quantum radar operates at much lower energies than conventional systems, which creates long-term potential for a range of applications in bio-medicine, such as non-invasive scans.

A special converter (a double-cavity device that couples the microwave beam to an optical beam using a nano-mechanical oscillator) was the key to the new system, according to the research team.

"Such a non-invasive property is particularly important for short-range biomedical applications," says the head of the research team, Dr. Stefano Pirandola, of the University of York’s Department of Computer Science and the York Centre for Quantum Technologies.

“In the long-term, the scheme could be operated at short distances to detect the presence of defects in biological samples or human tissues in a completely non-invasive fashion, thanks to the use of a low number of quantum-correlated photons," he says.