Castelló, Spain - Recognizing that production of femtosecond lasers for micromachining is still slow and expensive, researchers in the GROC Optics Group at James I University have developed an original parallel-processing technique that could multiply their production capacity, thus improving their performance, reducing the time and cost of manufacturing, and optimizing the use of laser energy.
|Jesús Lancis of the Grup d'Òptica de Castelló (GROC). (All photos courtesy of Àlex Pérez)|
Jesús Lancis, director of the GROC Optics Group, highlights that the progress achieved "will significantly improve the performance of this technology because it will enable to process the material simultaneously in several locations and, besides, without losing accuracy. Both facts are key to increase the production rate of laser technology, thus lowering manufacturing costs and allowing their gradual introduction into various sectors which used more traditional production mechanisms hitherto."
The parallel-processing technique the researchers developed enables splitting the laser beam into a series of multiple beams through what is called a "compensated dispersion module." It has already proved its effectiveness to simultaneously generate 52 blind holes measuring less than 5µm in diameter on a stainless steel sample. "This research shows that we can increase production speed by a factor of 52, or even 100, without losing quality, with the change of system parameters," explains Gladys Mínguez-Vega, a researcher in the GROC Optics Group.
|Gladys Mínguez-Vega of the Grup d'Òptica de Castelló (GROC).|
Pulsed femtosecond laser technology has provided a greater precision and quality, says Mínguez-Vega. "These lasers are being used, for example, in some surgical operations for less invasive, more localized, and precise cuts, or in the development of micromachining in all types of materials, including the biodegradable ones. With so short exposure times and with such a high energetic charge, femtosecond lasers also prevent heat from spreading beyond the point to which it is addressed, even allowing their use for cutting explosives," she adds.
|Grup d'Òptica de Castelló (GROC).|
The fact that energy is so concentrated means that it has to be softened. "If you spent all this energy, you will deposit so much energy that you would end up causing damage to the material. To avoid this, we use some filters that reduce light to the right energy," Mínguez-Vega explains. The matrix the researchers developed allows splitting the beam and multiplying the points of light while reducing the energy of each one of them. "Currently, for micromachining a piece with a femtosecond laser, we have to move the laser or the material to scan it, so production has to be performed point to point," she adds. The matrix they developed divides beams and keeps their effectiveness, enabling micromachining of dozens of different pieces simultaneously and multiplying by hundred the speed of the system with the subsequent cost reduction.
Full details of the work appear in the journal Optics Express; for more information, http://dx.doi.org/10.1364/OE.21.031830.