"March 2019: Center for Laser Materials (ZLM) successfully established"
Erbium-doped lutetia crystal (Er3+:Lu2O3) grown by the OFZ method | Photo: Anastasia Uvarova © IKZ
The world’s first diode-pumped terbium-laser
| Photo: Christian Ehlers © IKZ
The laboratories and research facilities at the Center for Laser Materials - Crystals (ZLM-K) were set up since August 2016 under the guidance of Dr. Christian Kränkel. Initially, the aims of the BMBF-funded Project "EQuiLa" on the research and qualification of innovative laser materials and crystals were the main focus of the research at the ZLM-K.
In materials processing, medicine or in metrology - lasers are ubiquitous in daily life. Nevertheless, even nearly 60 years after the invention of the laser, optimized lasers are not yet available for every area. In many cases this results from the lack of a suitable laser material for the laser light generation. To find a remedy in such cases is the aim of the future research at the new Center for Laser Materials at the Leibniz-Institut für Kristallzüchtung (IKZ) in Berlin Adlershof.
For the project acquired in cooperation with the Ferdinand-Braun-Institut (FBH) state-of-the art furnaces for the growth of highly melting crystals by the optical floating zone technique (OFZ) were set up at the IKZ. The successful growth of erbium-doped lutetia is a first evidence for the suitability of this approach. The crystal grower, Anastasia Uvarova, PhD-student at the ZLM-K, is happy about this result: "This otherwise difficult to grow crystal is important for mid-infrared lasers, which are needed for example in laser scalpels in medicine."
Visible lasers were another topic in EQuiLa, which is investigated at the ZLM-K. Due to their emission in the visible, terbium-doped fluoride crystals as active media are suitable for the direct and efficient generation of green and yellow laser radiation. Within the project, the first diode-pumped terbium-doped solid-state laser based on terbium-doped lithium-lutetium-fluoride (Tb:LiLuF4) was set up. "The first application of such a simple pumping source is an important step toward the commercial use of terbium-lasers", says laser specialist Elena Castellano, who is also a PhD-student at the ZLM-K.
Dr. Christian Kränkel, leader of the Center for Laser Materials, elucidates the concept: "The research at the Center for Laser Materials at IKZ and FBH covers the whole value chain of diode-pumped solid-state lasers starting from the growth of laser crystals and their polishing over the growth of semiconductor-films for laser diodes and their packaging and ending with setting up laser demonstrators".
A diode-pumped chromium-laser was set up as a proof-of-concept at the end of the project “EQuiLa”: The gain material, a chromium-doped Lithium-calcium-aluminium-fluoride crystal (Cr3+LiCaAlF6), was grown and polished at IKZ, while the pump source, an indium-gallium-phosphide-based (InxGa1-xP) red-emitting laser diode, was built at the FBH.
These results pave the way for further successful research and development works in the area of innovative diode-pumped solid-state lasers based on laser crystals grown at IKZ.