Novel crystalline materials for multi-color visible laser sources – NOVELA

The goal of the project is to develop novel functional inorganic materials based on fluoride and oxide crystals and single-crystalline thin films heavily doped with rare-earth ions, and to demonstrate their suitability for compact, high brightness, powerful and ultrashort-pulse laser sources directly emitting visible radiation in the green, yellow and red. Such lasers are of practical importance for display technology, medicine, material processing, microscopy and research. Many important tasks require particular laser wavelengths (colours), e.g., yellow laser radiation is of key importance for ophthalmology. Currently, the main challenge for a real breakthrough in creating a novel family of multi-colour visible lasers appears in the material field. In the project, we plan to focus on three laser-active ions: praseodymium (Pr3+), terbium (Tb3+), and europium (Eu3+). For Pr3+, the challenge is a search of a material providing broadband emission properties which can lead to generation of ultrashort pulses. For Tb3+, the challenge resides in the extremely weak absorption in the blue, and the need to evaluate the criteria of suitability of host matrices for this dopant. For Eu3+, the challenge is the understanding of the mechanisms preventing the laser operation in the red, such as excited-state absorption. The potential of oxide materials as compared to fluorides has to be revealed. Very little attention has been paid to visible waveguide lasers based on Tb3+ and Eu3+ ions. The innovative idea is to focus on highly-doped (up to stoichiometric compositions, 100 at.% doping) materials containing Eu3+ and Tb3+ ions, as well as disordered crystals containing Pr3+ ions featuring inhomogeneously broadened emission bands supporting ultrashort pulses. The originality of the project objectives is to achieve ultrashort pulses in the visible directly from a solid-state laser, as well as to address specific laser wavelengths in the visible with high-brightness sources.