Right now, the laser can concentrate 250 nanowatts of power on a 30-nanometer-wide spot. "Our technology can be scaled down to 5 to 10 nanometers for sure," says Sakhrat Khizroev, an electrical-engineering professor who is leading the work at UCR. A 10-nanometer spot size should be small enough to get a density of 10 terabits per square inch.
He and his colleagues make their 250-nanowatt laser by depositing a very thin layer of aluminum on the emitting side of a semiconductor diode laser. Then they focus a beam of positive gallium ions on the aluminum to etch tiny nanoscale apertures. As predicted by physics theory, a C-shaped aperture lets the most energy come through into the smallest spot size.
there are many engineering challenges to solve before the technology can be brought to market. They include mounting the laser on a slider so that it can move to various areas of the hard disk to record data, designing a new disk material that works with heat-assisted recording, and making disk lubricants that can handle the high temperatures during the heat-assisted writing process.
"Heat-assisted magnetic recording is a real systems problem and requires development and progress on a lot of fronts simultaneously," Schlesinger says. "The nanolaser is a nice step forward and brings the technology closer."