Diamonds and sapphires allow masers to operate continuously

Scientists from Imperial College London and UCL used a synthetic diamond grown in a nitrogen-rich atmosphere to create a new maser that operates continuously.

A maser (microwave amplification by stimulated emission of radiation) is the older, microwave frequency sibling of the laser. It was invented in 1954 and has traditionally been used in deep space communication and radio astronomy.

However, early versions of the maser had to be cooled to temperatures close to absolute zero (-273°C) to be able to function and even though in 2012 researchers were able to demonstrate that a maser could operate at room temperature using the organic molecule pentacene, the system produced only short bursts of maser radiation that lasted less than one thousandth of a second.

But with the new additions, carbon atoms were ‘knocked out’ from the diamond using a high energy electron beam, creating spaces known as ‘vacancies.’ A press release by Imperial explains that the diamond was then heated, which allowed nitrogen atoms and carbon vacancies to pair up, forming a type of defect known as a nitrogen-vacancy (NV) defect centre.

When placed inside a ring of sapphire to concentrate the microwave energy and illuminated by green laser light, the maser worked at room temperature and continuously.

“This breakthrough paves the way for the widespread adoption of masers and opens the door for a wide array of applications that we are keen to explore," said lead researcher Jonathan Breeze in the media statement.

According to Breeze and his team, such applications could range from medical imaging and airport security scanning, to improvements in sensors to remotely detect bombs. Masers, they say, could also be used to develop new technology for quantum computers and space communication methods to potentially find life on other planets.