Writing Words in the Air Without Pen and Ink Now Possible with New Laser Technology

Chinese researchers recently exhibited a laser that can create mystical Chinese characters through thin air.

Essentially, as specified in a Futurism report, lasers have already been employed to create an array of optical illusions, although, in the past, they needed dust or clouds as a medium.

However, the scientists behind this new device claim it can draw patterns anywhere by applying ultra-short laser pulses to strip off the electrons from air molecules and transform them into light, producing what's described as a "ghostly image" that floats in mid-air.

Earlier this week, in one demonstration at the Hongtuo Joint Laboratory of Ultra-Faster Laster in the optics valley of Wuhan, researchers produced characters that were seen from any angle and which the study authors could "touch" with their hands.

Drawing in the Air Without Paper and Ink

The lead scientist at the laboratory, Cao Xiangdong, said, with this brand new device, one can draw in the air minus paper and ink.

Moreover, the new invention works by focusing high-intensity laser pulses in the air to produce plasma or ionized gas, which emits energy in the form of light.

The researchers claimed they had employed a 3D scanner so they could arrange the pixel data and eventually form the characters accurately in the air, although they did not explain how the technology works.

The short pulses last only femtoseconds, a unit of time equivalent to one-millionth of one billionth, or one quadrillionth, of a second.

Safe to Use for Everyday Settings

According to a South China Morning Post report, because of the concise period of the pulses, the power peaks of the lawyer pen of Cao's team can reach one million megawatts, "not far off the total utility-scale electricity generating capacity of the United States.

Nonetheless, the average input power of the device is just a few tens of watts. Meaning that it could be used safely in daily settings.

The exhibition is an accumulation of their study over more than ten years, explained Cao in the report. To "light" the air, he continued explaining, lasers need to reach an energy density of a trillion wats or 100 terawatts per square centimeters.

This, then, depicts a challenge to a lot of other laser emitters of a similar type, although the researchers believe the technology has room for more improvement, not to mention more accurate control of the laser pulse's distribution, which will enable them to produce brighter, larger four-color images in the air.

Femtosecond Lasers

Cao and the team hope that the technology will one day have a practical use in fields including brain imaging, high-precision manufacturing, quantum computing, and medical instruments.

In 2021, another femtosecond laser-based device developed by the lab, a disinfection machine, was verified by Wuhan University's National Laboratory of Viruses for use in destroying viruses and bacteria, including the COVID-19 virus.

ScienceDirect describes femtosecond lasers as "having shown promising applications in bio, aerospace, and energy sectors" in the past years.

As explained, the primary tool behind the femtosecond laser surface modification is the multiphoton phenomenon and nonthermal processes.

Related information about laser technology is shown on Trotec Laser's YouTube video below:

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