Disposable and cheap lasers can now be made from inkjet printers, a new research has revealed.
Scientists from Hungary and France were able to develop laser chips made from organic materials using inkjet printers. Costing mere cents, these chips are cost-effective alternatives to replace deteriorating parts across different industries.
Organic Lasers
Lasers are composed of a pump source, optical resonator, and a gain medium that changes the wavelength of light and is responsible for the narrow red beam. In organic lasers, the gain medium used is a carbon-based material. While the material can cover a wide range of wavelengths, it degrades rapidly.
The researchers postulated that the only way for organic lasers to gain ground is by making it affordable to develop.
Popular methods of building laser chips typically apply spin coating wherein dye solution is rapidly spun to make the centrifugal force evenly spread the liquid onto a thin film. The rapid spinning often causes spillage and wastage, that only 2 percent of the liquid is used.
The researchers said their findings' advantage over conventional methods is its cost effectiveness. By using inkjet printers, liquids are injected accurately on the material without wasting any raw material.
Associate professor of microelectronics at Ecole Nationale Supérieure des Mines de Saint-Ếtienne and study lead author Sébastien Sanaur said that creating laser chips using inkjet printers does not require the operator to use any protective equipment, laboratory, or special type of material.
"By piezoelectric inkjet printing, you print 'where you want, when you want,' without wasting raw materials," said Sanaur.
To print the laser dyes, the researchers needed to mix them with an ink. They experimented with commercially sold inks and dyes and found EMD6415 to have suitable optical and printing properties. The solution was then printed onto clear quartz panels, measuring 0.08 square inch pixels. The laser chips were placed in between two mirrors, which reflected the light through the gain medium. The light energy input was provided by another laser, which acted as its pump. The produced lasing capsules can change beams from yellow to deep red.
Laser Applications
University of St. Andrews School of Physics and Astronomy professor and organic laser expert Graham Turnbull, who was not part of the study, said that cheap laser chips have many applications.
"The lasers could have future applications as disposable light sources for chemical analysis such as medical screening or pollution monitoring," said Turnbull.
Polytechnique Montréal Department of Engineering Physics assistant professor Stéphane Kéna-Cohen commented that the creation of organic chips that are tuneable can span the whole visible spectrum. But Kéna-Cohen expressed concern that the organic lasers still necessitate an external, high-energy laser. If these lasers can be pumped electrically or with energy efficient LEDs, it would be indeed a practical breakthrough, added Kéna-Cohen.
The study was published in the Journal of Applied Physics on May 3.
