Scientists have developed a palm sized femtosecond laser using a glass substrate

Researchers at the Federal College of Technology in Lausanne (EPFL) have shown that femtosecond lasers suitable for palm size can be manufactured using glass substrates.

Can femtosecond lasers made entirely of glass become a reality? This interesting question prompted Yves Bellouard, the head of the Galata laboratory at the Federal Institute of Technology in Lausanne, to embark on a journey after years of arduous laboratory experiments to calibrate femtosecond lasers.

The Galata laboratory is located at the intersection of optical, mechanical, and material sciences, and considers femtosecond lasers as a key component of Bellouard's research.

Femtosecond lasers generate extremely short and consistent laser pulses, which can be used for various applications, such as laser ophthalmic surgery, nonlinear microscopy, spectroscopy, laser material processing, and more recently, sustainable data storage.
Typically, commercial femtosecond lasers are constructed by assembling optical components and their mounting bases onto a substrate (usually an optical bread board), requiring detailed optical alignment.

Bellouard and his team have designed a solution that involves using commercial femtosecond lasers to manufacture compact femtosecond lasers made of glass, with sizes no larger than standard credit cards, significantly reducing alignment challenges. Their work results have been recorded in the magazine "Optica".
Researchers use commercial femtosecond lasers to carve complex channels on glass, enabling precise placement of key components required for laser systems.
Although micrometer level accuracy has been achieved during the manufacturing process, only the grooves and components cannot achieve the alignment required for laser quality performance. Simply put, the mirror is not fully aligned, resulting in its glass device being unable to function as a laser at this stage.

Based on previous research, scientists have also realized that they can locally manipulate the expansion or contraction of glass. They decided to use this technology to fine tune the alignment of the mirror.

Therefore, the initial etching process was specifically designed to incorporate a mirror into the groove content equipped with micro mechanical bending. These bending designs are used to adjust the position of the mirror when exposed to femtosecond lasers.

This innovative method transforms commercial femtosecond lasers into tools for a second purpose: aligning mirrors. Ultimately, this process resulted in a stable small femtosecond laser.

The ongoing research project at Galata Laboratory will delve into the application of this technology in the field of assembling quantum optical systems. This exploration aims to break through the limits currently achievable in miniaturization and precise alignment.
At present, the alignment process is still under the supervision of manual operators, and after practice, it may take several hours to complete. Despite its small size, this type of laser can generate a peak power of approximately 1 kilowatt and emit pulses with a duration of less than 200 femtoseconds - a duration almost insufficient to allow light to pass through human hair.

Innovative femtosecond laser technology will be spun off to form a new company called Cassio-P, led by Antoine Delgoffe.

Source: Laser Network