The core of the new room-temperature maser
When the laser was first invented, it was “a solution waiting for a problem,” a piece of cutting-edge technology with no applications. Today, found in everything from sensors to communications to surgery, the laser has come into its own—but it may be time to step aside and share the spotlight with its older brother, the maser.
Lasers and masers work on the same principle, amplifying light through a process called stimulated emission, except that lasers amplify visible light while masers act on microwaves. Light and microwaves are both forms of electromagnetic radiation, but microwaves have a wavelength 100,000 times greater than that of visible light. But although the maser has been used for deep-space communications and atomic clocks, lasers have always outshone their predecessors. And masers have only themselves to blame, as these finicky devices require extreme conditions like vacuum or cold temperatures. Now, however, researchers have finally produced a maser that functions while surrounded by air at room temperature.
While the room-temperature maser is currently a solution with few applications, it may rise to prominence for its amplifying ability. Amplifiers are a vital component in any electronic circuit. The lower their noise, the better amplifiers perform—and masers have very little noise. There’s just one flaw keeping room-temperature masers out of everything from your GPS receiver to your smartphone: the current incarnation of the room-temperature maser, still in the early days of its development, is a power-hungry device the size of a coffee cup.
“The crucial thing to point out is that this device has in no way been optimized,” says the study’s lead author, Mark Oxborrow. “Nobody really knows what the limits are. That’s what’s exciting about it.” Early lasers and even transistors were also large and ineffective, but as researchers kept tinkering with them, they gradually shrank down and wound up revolutionizing electronics. With more development, room-temperature masers could improve radio telescopes and medical scanners, and beyond. “Because amplifiers are so fundamental,” Oxborrow explains, “if they can be shrunk down, masers have a good chance of finding applications in many places.”
Image courtesy of National Physical Laboratory, Teddington, UK