Scientists use diamond in world's first continuous room-temperature solid-state maser

March 21, 2018, Imperial College London
A diamond containing nitrogen-vacancy (NV) defects centres is illuminated by a 532-nm green laser. The red light because the NV centres fluoresce. Credit: Jonathan Breeze, Imperial College London

The maser (microwave amplification by stimulated emission of radiation), the older microwave frequency sibling of the laser, was invented in 1954. However unlike lasers, which have become widespread, masers are much less widely used because in order to function they must be cooled to temperatures close to absolute zero (-273°C).

However, this new study from Imperial College London and UCL, and published in Nature, reports for the first time a maser that can act continuously at .

Lead researcher Dr Jonathan Breeze, from Imperial's Department of Materials, said: "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. We hope the maser will now enjoy as much success as the laser."

In 2012, scientists demonstrated that a maser could operate at room temperature using the organic molecule pentacene. However, it only produced short bursts of maser radiation that lasted less than one thousandth of a second. In any case, had the maser operated continuously, the crystal would likely have melted.

Now, Dr Breeze and colleagues have used a synthetic diamond grown in a nitrogen-rich atmosphere to create a new maser that operates continuously.

Carbon atoms were 'knocked out' from the diamond using a high energy electron beam, creating spaces known as 'vacancies'. 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. The diamond was provided by Element Six.

The diamond is held inside a sapphire ring and illuminated by 532-nm green laser. The red light is fluorescence from the NV centres. Credit: Thomas Angus, Imperial College London

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

Co-author Professor Neil Alford, also from Imperial's Department of Materials, said: "This technology has a way to go, but I can see it being used where sensitive detection of microwave radiation is essential".

The team who made the discovery say masers could be used in a range of applications such as medical imaging and airport security scanning. They have more traditionally been used in deep space communication and radio astronomy.

As well as medical imaging and airport security scanning, masers could play a pivotal role in improving sensors to remotely detect bombs, new technology for quantum computers, and might even improve space communication methods to potentially find life on other planets.

Explore further: Proposed diamond maser could operate at room temperature

More information: Jonathan D. Breeze et al. Continuous-wave room-temperature diamond maser, Nature (2018). DOI: 10.1038/nature25970

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11 comments

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Spaced out Engineer
1 / 5 (2) Mar 21, 2018
Looking forward to sensitive detection of microwave radiation. Seeing as how Michigan is the only state with life imprisonment for electronic harassment, yet the Frey auditory effect has been around for awhile.
https://phys.org/...ces.html
It might be nonlethal, but the tinnitus is very painful and leads to sleep deprivation, which could lead to death.
Osiris1
1 / 5 (4) Mar 21, 2018
Maybe the folks 'harrassing' consular and embassy officials in the old Cuban embassy could be served with a warrant for arrest and extradition back to Michigan to face life as lifers....on condition thay stay away from 'Bubba' who is always looking for lightweight and short male 'wives'...so the 'miscreants' can stay alive.
However, Cuba may not want to admit an arrest party from a small monopolist and 'rigtht to work' American 'redddd' state that cares not one whit for workers. Fact is, is Michigan prepared to raise 900,000 Michigan crack 'ranger or Green Beret' troops to force this kidnapping against the certain presence of Cuban allied troops from North Korea....600,000, and China 4,000,000 troops, 15000 artillery and 8000 tanks? I detect the clear odor of another Bay of Pigs...about thousands of American GreedyOldPigs to be sure. Maybe those militant evan-Jelly-kals would not like to die on socialist ground.
PinkElephant
5 / 5 (2) Mar 21, 2018
What're the odds that this could be useful as a more-or-less drop-in replacement for lidar lasers in self-driving cars? The advantage of microwaves being resilience vs. difficult-weather conditions (such as heavy fog, rain, snow, dust)...
PTTG
not rated yet Mar 22, 2018
Masers as an anti-drone weapon should prove useful, too.
Da Schneib
not rated yet Mar 22, 2018
Masers for communications, both open and closed circuit. Helical wave guide is cheaper than fiber optics these days, IIRC, and masers in the open air would be less affected by weather.

Cheap radar. Really cheap. Very accurate too. And potentially quite hard to jam.

I don't think they'll replace the magnetrons in microwave ovens. Magnetrons are pretty cheap too, and not so intense; easier to shield the user from them.

And quite a few other applications, I think.
antialias_physorg
not rated yet Mar 22, 2018
I don't think they'll replace the magnetrons in microwave ovens

Why would you even want to? Microwave ovens do not require coherent radiation. There's no advantage in using a maser over just any other source of microwaves as long as the frequency is the correct one.
mackita
not rated yet Mar 22, 2018
dnatwork
not rated yet Mar 22, 2018
I don't think they'll replace the magnetrons in microwave ovens

Why would you even want to? Microwave ovens do not require coherent radiation. There's no advantage in using a maser over just any other source of microwaves as long as the frequency is the correct one.

Maybe if you had an array of low-power masers that you could focus on a point inside the food, you could heat the inside at the same rate as the outside.
mackita
not rated yet Mar 22, 2018
The energy efficiency of above maser is few percents at best: you would need an array of megawatt range lasers and pile of optical quality diamonds for millions dollars for to heat your beans with sausage in fancy maser way..
dnatwork
not rated yet Mar 26, 2018
Yes, why bother thinking about different ways to do things. It can't work any better, we already know everything.
mackita
not rated yet Mar 26, 2018
I didn't say, there aren't better ways how to do it - it was you who implied it... ;-)

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