Autore: ExtremeTech

Blue laser

Though lasers are seen as a sci-fi technology of the future, they’re already prevalent and highly advanced today. However, just because they’re prevalent doesn’t mean they don’t have a significant amount of space to evolve into something more useful than their current state. Now, researchers have developed the first digital laser, which is capable of changing the shape of its own beam.

For the most part, lasers aren’t particularly complex devices; they consist of mirrors, energy, and a casing. Usually, the energy is light, and mirrors help project the light from within the casing. In order for the light to turn into a laser, though, the casing must contain a gain medium — something that alters the frequency of the original light, changing it into a laser, typically some sort of crystal or glass. The laser is then redirected out of the casing using a mirror. The shape of the laser coming out of the casing is dictated by not only the intensity of light being used, but various add-ons that can be applied to alter the beam, such as extra mirrors or lenses. These add-ons that alter the beam are semi-permanent, in that they cannot change on the fly. They have to be attached to the laser, and calibrated each time, which is why lasers are currently considered to be not-digital.

Laser shapes

Now, however, Sandile Ngcobo with the University of KwaZulu-Natal, and a team of researchers have successfully tested a laser that can change the shape of its beam without all of the labor involved of changing and recalibrating the add-ons. Rather than have the laser shoot out of the casing, then into something that modifies the shape, the team managed to stick the modifier inside the casing itself, thus allowing the beam to emerge from the casing in the desired shape to begin with. What makes the laser digital is that the new modifier — and thus the shape of laser beam — can be manipulated through the use of a computer.

As shown in the chart above, the team has already managed some complex laser shapes. Applications for dynamically changing a laser’s shape aren’t simply limited to theme park light shows and trippier concert lighting, but can be used in (among other things) optical tweezers, which are tiny lasers that can manipulate microscopic objects, kind of like a tractor beam.

We can all still hope for trippier concert lighting, though.

Now read: NASA uploaded the Mona Lisa to the Moon using lasers

Research paper: DOI: arXiv:1301.4760 – “The digital laser”