A team of Polish-based scientists is reporting a new femtosecond laser – with the latest light source that can change fixtures for different applications.
Laser stores are often built specifically to meet specific applications – from observing objects in the outdoor space, treating diseases in the human body to making materials in the microbes and the environment. nanoscales.
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A new class of laser
“Our goal is to develop new ones,” Yuriy Stepanenko, study director and team leader at Ultrafast Laser Technologies at the Institute of Physical Chemistry of the Polish Academy of Sciences, said in a statement. He also states that they deal with sources that are capable of delivering “ultrashort light pulses,” or those in the femtosecond pulses. A femtosecond equals one to one-fifth of a negative (10-15), or one-part in a quadrilateral, of a second. Stepanenko says that this is the scale at which intracellular chemical reactions occur, and in order to “see” these events, they need to take a picture in that short time – and the new laser can do just that.
The Polish scientist also claims that the femtosecond laser can also be used to “precisely remove” foreign materials on a surface without damaging or even destroying them. For example, the famous Mona Lisa painting can be cleaned without damaging the layers of paint on the artwork. The femtosecond laser would only remove dust and dirt that is about 10 nanometers thick, according to Stepanenko.
Dr Bernard Piechal, co-author of the study, says the laser could even be “too precise” for the artwork application, saying the action only requires lasers in the nanosecond scale. As for the new laser, Piechal explains that it can be used to engrave precision paths in ultrathin materials, such as scraping gold off microchips with precise depth measurement. Using a nanosecond laser for such applications could dissolve the silicon in the chip or break the glass with the longer exposure time.
Their findings are published in the Journal of Lightwave Technology.
Creating harmonics in light pulses
Piechal explains that they were aiming for a laser source that could meet two conditions. The first is that the source must be “subject to a minimum of mechanical stress,” and the second is that the source must be movable. He led the researchers to fiber-optic lasers, which, according to Stepanenko, are “essentially the closed optical fiber in a ring.” The light within these fibers is highly protected from mechanical disturbances, emitting pulses of light consistently even when physically moved or rubbed.
The other challenge is the frequency of the light beats being emitted. Consistently, the frequency affects the entire length of the fiber optic loop through which the light passes, and higher frequencies would require longer cables, which was not particularly suitable for the light-emitting. research. Then they reduced the circumference of the loop. But still, the pulses achieved were around 60 nanoseconds. To work around this limitation, researchers designed a system that could double the frequency to achieve a higher output, similar to creating harmonic frequencies, in a technology called Harmonic Mode Locking.
Stepanenko compares the tech to a guitar, where the basic frequency is like an open string. They can then choose which harmonics to use, similar to getting a higher note on a guitar string by pressing the center of the fretboard.
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