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.
What’s the News: Scientists have developed a laser that’s small and tough enough to work in the combustion engine of a vehicle yet powerful enough to ignite the fuel-air mixture that drives combustion cylinders. The researchers say that laser-ignited combustion engines could be more fuel efficient than traditional spark-plug ones: Unlike spark plugs, which transmit their sparks in milliseconds, lasers transmit energy within nanoseconds. Inventor Takunori Taira says that “timing—quick combustion—is very important. The more precise the timing, the more efficient the combustion and the better the fuel economy.”
What’s the News: In a demonstration near California’s San Nicholas Island last Wednesday, scientists with the U.S. Navy tested a laser weapon aboard the USS Paul Foster by shooting a 15-kilowatt beam at an inflatable boat from a mile away, causing the outboard engines to burst into flames. It was the world’s first successful water-test of a high-energy laser. “I spent my life at sea,” Rear Adm. Nevin Carr told Wired, “and I never thought we’d see this kind of progress this quickly, where we’re approaching a decision of when we can put laser weapons on ships.”
Weapons-grade lasers still sound like the stuff of science fiction, but thanks to a major breakthrough by researchers at the Los Alamos National Lab in New Mexico, the Navy has taken a big step toward making this bit of sci-fi real. With the Free Electron Laser (FEL) program, the Navy hopes to use laser beams to blast enemies out of the sea and sky, and for the first time, they’re starting to generate enough power to do so, with the newfound ability to create a megawatt-level laser beam.
“The injector performed as we predicted all along,” said Dr. Dinh Nguyen, senior project leader for the FEL program at the lab. “But until now, we didn’t have the evidence to support our models. We were so happy to see our design, fabrication and testing efforts finally come to fruition. We’re currently working to measure the properties of the continuous electron beams, and hope to set a world record for the average current of electrons.” [Office of Naval Research]