New Study Reveals Exceptional Laser Performance in Thulium Doped Ceramics

A team of scientists at the Intense Laser Irradiation Laboratory (ILIL) at The National Institute of Options (CNRINO) in Pisa, Italy, including EuPRAXIA members Dr Luca Labate and Dr Leonida Gizzi and EuPRAXIA Doctoral Network Fellow Alex Whitehead, have published a paper outlining their work developing a new type of laser medium that works at a wavelength of 2 µm. This is an important range for medical, industrial, and scientific technologies. Their work, recently published in High Power Laser Science and Engineering, shows that using a ceramic material infused with the rare-earth element thulium can make lasers more powerful and efficient.

The researchers used a ceramic called Tm: Lu₂O₃, which contains thulium atoms. When they shine a laser diode into it, the thulium atoms absorb the energy and emits it in the mid-infrared regime. What makes this special is how efficiently this process works in the ceramic.

The team measured a 73% slope efficiency, meaning nearly three-quarters of the input energy gets turned into laser light, a very high number for this kind of solid-state laser. One important element for this efficiency is a process called cross-relaxation. In simple terms, one excited thulium atom can "share" its energy with a nearby thulium atom, so both become excited and ready to emit laser light. This double-pumping effect means more energy gets turned into useful light, with less waste.

The lasing was demonstrated experimentally, and the laser power was measured at different temperatures. They also developed an analytical model to simulate the laser dynamics and presented a strong correlation with the experimental data.

Lasers at 2 microns are useful in many fields such as in medicine for surgery and imaging, in industry for cutting and welding and in science for driving next-generation laser systems and even particle accelerators. This ceramic laser design is also cheaper and easier to manufacture than traditional crystal lasers, making it a promising option for future high-power laser systems.

This research shows that thulium-doped ceramics can be a powerful and efficient material for next-generation lasers. This shows great promise for offering high performance at lower cost.

The full paper can be found here.