Chinese scientists invent laser so powerful it can write words in mid-air

The laser works by stripping the electrons off air molecules using ultra-short laser pulses and turning them into light, thus creating a ghostly image floating in mid air. (Image credit: Hongtuo Joint Laboratory)

Scientists in China have invented a powerful laser which can essentially scorch the air to create patterns. Lasers have already been used to create optical illusions, but they needed dust or clouds as a medium.

The Wuhan-based team demonstrated the laser by writing Chinese characters in the air, which can be viewed and even touched.

The laser works by stripping the electrons off air molecules using ultra-short laser pulses and turning them into light, thus creating a ghostly image floating in mid air. The researchers hope the technology can be implemented in various fields, ranging from brain imaging, to quantum computing, reported South China Morning Post.

“With the brand new device, we can draw in the air without using paper and ink,” Cao Xiangdong, lead scientist at the Hongtuo Laboratory of Ultra-Fast Laser in Wuhan’s optics valley, told Science and Technology Daily. “The display is an accumulation of our research over more than a decade.”

The displays are created using pulses that last for just a few femtoseconds or one millionth of one billionth, of a second. The device, however, requires a million megawatts of power to shoot the laser.

To turn air into light, the device needs roughly a trillion watts per square centimetre of the pattern or writing displayed, South China Morning Post reported.

The laser was unveiled weeks after Chinese President Xi Jinping visited laser companies in Wuhan to boost advanced technology sectors in the country.

He described the development of such technology as a matter of “great urgency” and stressed on the need for scientific and technological self-reliance, the publication stated.