Infrared laser charger beams power to devices 30 metres away

Infrared laser charger beams power to devices 30 metres away
Researchers have discovered a new method to wirelessly transmit power over the air up to 30 metres away.

This breakthrough could lead to technology that automatically charges devices as soon as it is brought into a room.

Scientists at Sejong University used infrared light to develop a wireless charging system over 30 metres, using a transmitter that can be set up in a room, as well as a receiver that can be incorporated into electronic devices.

The transmitter works as an optical power source, using an erbium-doped fibre amplifier to produce a beam of infrared light with a central wavelength of 1,550 nanometres.

The beam is fired through the air to hit the receiver, which is made up of a spherical lens retroreflector. This focuses incoming light into a point in the centre, where a photovoltaic cell waits to absorb the light and produce electricity.

If the line-of-sight between transmitter and receiver is broken, the device can automatically switch to a low-intensity safe mode.

During tests, the team were able to transmit a 400-mW beam of light over 30 metres, where the receiver converted the light into 65 mW of electrical power.

The team believes that the technology could be scaled up to charge everyday electronics. At present, the team is also aiming to improve the efficiency of the photovoltaic cell to boost electrical output, as well as identifying a way to charge multiple devices at once.