What is a maser?
The word 'maser' is derived from the acronym MASER (Microwave Amplification by Stimulated Emission of Radiation). Devices based on this process and known as masers were developed by scientists more than 50 years ago, even before the first lasers were invented. Instead of creating intense beams of light, as lasers do, masers deliver a concentrated beam of microwaves.
How do they work?
Conventional masers work by amplifying microwaves using crystals such as ruby - this process is known as 'masing'. However, the maser has had little technological impact compared to the laser because getting it to work has always required extreme conditions that are difficult to produce; either extremely low pressures or temperatures close to absolute zero. To make matters worse, it is also often necessary to apply strong magnetic fields using large magnets.
How is the new maser different?
The NPL and Imperial College London maser uses a completely different type of crystal, namely p-terphenyl doped with pentacene, to replace replace ruby and replicate the same masing process at room temperature and with no applied magnetic field. This means that the cost to manufacture and operate masers could be dramatically reduced, which could lead to them becoming as widely used as laser technology is today.
What are the potential applications?
Room-temperature masers could be used to make more sensitive medical instruments for scanning patients, improved chemical sensors for remotely detecting explosives, lower-noise read-out mechanisms for quantum computers and better radio telescopes for potentially detecting life on other planets.
A physics breakthrough
The maser research was one of Physics World's top 10 breakthroughs for 2012. Criteria for judging the top 10 included: fundamental importance of research, significant advance in knowledge, strong connection between theory and experiment and general interest to all physicists.
Dr Mark Oxborrow discusses the maser.
For half a century the maser has been the forgotten, inconvenient cousin of the laser. Our design breakthrough will enable masers to be used by industry and consumers.
Dr Mark Oxborrow
Co-author of the study at NPL
Dr Mark Oxborrow's maser lecture at NPL.