In English, the word Maser is an abbreviation of the phrase "Microwave Amplification by Stimulated Emission of Radiation", which translates as "amplification of microwaves using stimulated radiation." In its action, it is similar to a laser, but operates in the microwave range.
A maser is a device that produces successive electromagnetic waves. It was first invented by physicists from the USSR and the USA Nikolai Basov, Alexander Prokhorov and Charles Townes in 1954. For this they were awarded the Nobel Prize.
Early models worked with a three-level pumping system, where a microwave source pumps energy into the working fluid of the emitter. As a result, hydrogen atoms and others move to a new energy level from a state of rest. This is accompanied by radiation in the microwave range.
A maser, unlike a laser, emits concentrated microwave beams rather than light. The ratio of the useful signal power to the noise power of the maser is lower, which is an advantage. However, it was inferior in power to a laser.
In fact, most of the masers so far have been gas emitters, where hydrogen atoms are used as a working medium. But the cost of such devices is very high because they are made from many expensive components. For the operation of the maser, temperatures and vacuum close to absolute zero were needed. Therefore, for a long time, it was little used.
Later, Mark Oxborrow and other British scientists invented a microwave quantum generator based on solid-state components. It is based on pentacene crystals, operates at room temperature and is compact in size. The developers believe that it can be used in radar and space communications, as well as to create a new generation of quantum computers and radio telescopes.
The signal from this device is many times stronger than the signal from a conventional maser. Now scientists are working to make it not just generate individual short impulses, but work constantly. It is also necessary to narrow the wavelength range covered for additional amplification.
This maser is powered by a two-level pumping system: a terphenyl crystal and pentacene are pumped by an optical laser. The crystal molecules move to a new energy level, as a result, photons are synchronously emitted in the microwave range.
