EPFL spin-off LakeDiamond has shown that beams emitted from a diamond-based laser could someday recharge drones in mid-flight.
The system, which poses no threat to human health, is composed of a lab-grown diamond measuring a few millimeters per side.
The EPFL spin-off contends that it could also be used to transmit both power and data to satellites and has just been included in the ten projects supported for two years by the Swiss Space Office.
No matter how versatile drones be, they do have a weak point: their battery.
This is particularly true of propeller drones, which are popular for information-gathering purposes in dangerous or hard-to-reach regions.
Such drones can fly for only around 15 minutes at a time because their engines quickly burn through their batteries.
One way of addressing this limitation – without weighing the drones down – would be to recharge them while aloft using a power beaming system.
LakeDiamond has demonstrated the feasibility of using such a high-power laser built around its lab-grown diamonds that are etched at the atomic level.
Standard laser beams are not as straight as they seem: as they travel, they expand ever so slightly, leading to a loss in density as they go.
LakeDiamond’s system on the other hand produces a laser beam with a wavelength of 1.5 µm that, in addition to being safe, can travel much farther without losing strength.
The light produced by a diode in the laser is directed at a booster composed of reflective material, an optical component and a small metal plate to absorb the heat.
The breakthrough lies not with this set-up, which already exists, but with the fact that the emitted beam is only a few dozen watts strong.
The spin-off’s system holds the world record for continuous operation using a wavelength in the middle of the infrared range – it delivers more than 30 watts in its base configuration.
The lab-grown diamonds’ key properties include high transparency and thermal conductivity. Achieving those things took the researchers over ten years of development, reports EPFL.
Image and content: Jamani Caillet/EPFL-LakeDiamond