Supercooled single photon detector shows potential for cancer treatment

Share this on social media:

Scientists from the University of Glasgow and the STFC Rutherford Appleton Laboratory have developed a supercooled single photon detector with a low enough power consumption to be used outside of a laboratory.

The work, published as a Letter in the journal Superconductor Science and Technology, could pave the way for use of advanced superconducting detectors for better cancer treatments, driverless cars and practical quantum communications.

The new superconducting nanowire single photon detector was made by adapting technology initially developed for European Space Agenecy's Planck mission for surveying cosimic background radiation. (Credit: University of Glasgow)

The research builds on existing developments in superconducting nanowire single photon detectors (SNSPDs). Normally, SNSPDs need to be cooled to a just few degrees above absolute zero (−273.15°C) in order to work effectively, a process which requires liquid helium or a great deal of electrical power to achieve.

The research team took a fibre-optic coupled superconducting detector supplied by the Dutch start-up Single Quantum, and housed it in a miniaturised cooler capable of reaching temperatures of 4.2 Kelvin, or -268.95°C, which runs from standard mains power. The SNSPD platform opens up a wide range of new applications for the technology.

Nathan Gemmell, of the University of Glasgow’s School of Engineering and the lead author of the work, said: ‘We’ve adapted technology initially developed for the European Space Agency’s Planck mission, which launched in 2009 and successfully surveyed cosmic background radiation in the microwave and infrared frequencies of the spectrum over four and a half years in space.’

The researchers have shown that the SNSPD can be used for infrared single-photon light detection and ranging, which could play a key role in the development of systems suitable for driverless cars in the future.

The Letter also discusses how the system was used to detect infrared photons at a wavelength of 1,270nm, the signature of a form of excited oxygen known as singlet oxygen, which plays a key role in many biological and physiological processes.

In a cancer treatment called photodynamic therapy (PDT), the treatment drug exchanges energy with surrounding oxygen molecules on optical excitation, creating singlet oxygen radicals which kill tumour cells. A miniaturised cooling platform like this one would make SNSPD use in clinical PDT much more practical, potentially making cancer treatments more effective, according to Professor Robert Hadfield, Professor of Photonics at the University of Glasgow’s School of Engineering and the lead researcher on the project.