Accueil > RECHERCHE > Matériaux et optique > Equipe OML > Activités de recherche > Axis 1 : Matériaux Instrumentation Laser (MIL)

New laser sources around 2 µm based on Tm-doped materials

par BRAUD Alain - publié le

Fundings :FASTMIR (LABEX EMC3, 2014-2018 – coordination), SPLENDID2 (ANR, 2020-2024 – coordination), NovaMat (RIN Tremplin recherche, 2019-2021 – coordination).
PhD and Post-doc involved :L. Guillemot, R. Soulard, M. Salhi…
Collaborations : CORIA (Rouen), Laboratoire Charles Fabry (Palaiseau), Universitat Rovira i Virgili (Tarragone) and Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy (Berlin)

The development of near-mid-infrared laser sources emitting at wavelengths within the 2.0-2.4 μm atmospheric window has raised a great interest in the recent years. In particular, 2.3 µm lasers based on the 3H4→3H6 transition of thulium ions are of interest for gas sensing [1-4] and non-invasive glucose measurement [5] because of its spectral overlaps with the absorption lines of carbon monoxide, methane, formaldehyde and glucose.Furthermore, the emergence of high-energy ultra-short lasers around 2.3 µm may pave the way for the development of new LIDAR systems in this spectral range [6], allowing to map the concentrations of such pollutants in the atmosphere. In order to develop efficient and affordable 2.3 µm laser, we have studied new pumping configurations [7], waveguide structures [8,9], ultrafast regime [10] and laser hosts [11-13]. In addition, we demonstrated the first 2.3µm laser working in mode-locked regime [10], as well as the first continuous-wave laser operation on this transition in oxides [11,13] and we showed the possibility to pump very efficiently at around 1µm through an excited state mechanism [7]. This work breaks technological locks for power scaling of 2.3 µm lasers because of the availability of high power, high brightness commercial sources at 1µm and because of the excellent spectral as well as thermo-mechanical properties of Tm-doped oxides and fluoride crystals, which are also suitable for short pulses generation.