This project aimed to develop innovative integrated light sources (waveguide lasers) emitting in the short-wave infrared spectral range (2–3 µm) for potential applications in greenhouse gas and air pollutant detection. From a materials perspective, the work focused on single-crystalline, oriented fluoride layers (LiYF₄) grown by liquid phase epitaxy under controlled inert atmosphere and doped with rare-earth ions (Tm³⁺, Ho³⁺, Er³⁺). The growth and microstructuring of these layers by precision diamond-saw dicing were achieved, followed by proof-of-principle demonstration of highly efficient, high-power, eye-safe fluoride waveguide lasers operating at 2 µm. The project also explored an alternative approach to mid-infrared fiber lasers based on fluoride (Er:ZBLAN) fibers for 3 µm sources.

Partners: Institut de Recherche de Chimie Paris – IRCP, Paris (Bruno Viana), CIMAP UMR6252 CNRS, Caen (Patrice CAMY), Laboratoire Charles Fabry, Institut d’Optique Graduate School, Palaiseau (Frederic DRUON), CORIA UMR6614 CNRS, Rouen (Ammar HIDEUR).

The SPLENDID2 project addresses key challenges in mid-infrared (MIR) photonics by developing innovative ultrafast laser sources (2–3 µm) for applications in soft material processing, surgery, and strong-field physics. This 36-month collaboration between CIMAP, IRCP, LCF, and CORIA focuses on femtosecond oscillators and high-energy, high-repetition-rate amplifiers beyond 2 µm, targeting performance levels not yet achieved with solid-state systems. The work is based on Erbium- and Thulium-doped oxide and fluoride crystalline materials. Two main approaches are pursued: (i) Tm³⁺-based systems at ~2.3 µm, enabling sub-ps, mJ-level pulses using hybrid fiber–bulk architectures, and (ii) Er³⁺-based mode-locked lasers and amplifiers at ~2.8 µm, including waveguide configurations for high repetition rates. The project combines material development, advanced laser architectures, and dispersion management strategies. Its expected impact includes breakthroughs in MIR ultrafast sources, enabling new scientific tools and future medical and industrial instrumentation, with strong potential for technology transfer and patenting. 

This project aims 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, high-power, and ultrashort-pulse lasers emitting directly in the visible (green, yellow, red). These sources are relevant for applications in display technology, medicine, material processing, microscopy, and research. The work focuses on three key ions—Pr³⁺, Tb³⁺, and Eu³⁺—addressing specific material challenges such as broadband emission for ultrashort pulses (Pr³⁺), weak blue absorption and host-matrix optimization (Tb³⁺), and limitations to red laser operation (Eu³⁺). The project also evaluates oxide versus fluoride hosts and explores highly doped (up to stoichiometric) materials, as well as disordered crystals enabling inhomogeneously broadened emission. The objective is to achieve direct visible ultrashort-pulse generation and high-brightness sources at targeted wavelengths. 

The FLAMIR project aims to produce fiber lasers in the mid-infrared (MIR) beyond 4 µm, based on chalcogenide glass (ChG) fiber doped with rare-earth (RE) ions such as Dy³⁺ or Pr³⁺. These materials are very promising for this application since they show low phonon energy and high refractive index, and consequently are suitable for obtaining high absorption and emission cross-sections in RE-doped glasses. For this purpose, two strategies will be developed to inscribe the Bragg gratings (BG), either by ultrafast laser inscription in the fiber core using a point-by-point process or by a phase-mask technique. Different pumping schemes will also be tested in order to achieve the highest RE emission efficiency. Finally, in FLAMIR, ChG should allow (i) high-content RE doping, (ii) low-loss fibers, and (iii) permanent BG writing. Taking into account theoretical calculations and preliminary results, MIR fiber lasers are reasonably expected within the FLAMIR project. 

Partners: Acamedic: CIMAP UMR6252 CNRS (Patrice CAMY, Pavel LOIKO); Laboratoire Hubert Curien, UMR5516 CNRS, Saint-Etienne (Emmanuel MARIN); CORIA UMR6614 CNRS, Rouen (Ammar HIDEUR). Industrial: Oxxius, Lannion; Le Verre Fluoré, Bruz; AlphaNov, Bordeaux.

The LUMEN project aims to develop high-power visible laser sources for optical instrumentation, with a strong focus on life science applications. Inspired by the success of high-power silica fiber lasers in the infrared, the project explores an alternative approach based on fluoride glass fibers, which are well suited for operation in the visible spectral range. The objective is to achieve compact, efficient, and robust visible lasers delivering watt- to tens-of-watts-level output powers, currently unavailable with existing technologies. Key challenges include adapting advanced fiber technologies—such as double-clad designs, fiber Bragg gratings, and pump–signal combiners—to fluoride glass platforms. In parallel, issues related to power scaling, reliability, and degradation mechanisms will be addressed to enable industrial deployment. The project combines material development, photonic component integration, and laser system optimization. Its outcomes are expected to enable breakthroughs in fields requiring high-brightness visible sources, including super-resolution microscopy, DNA sequencing, and quantum technologies. Ultimately, LUMEN seeks to establish a new generation of compact and efficient visible fiber lasers for advanced scientific and technological applications. 

Partners: Laboratoire Charles Fabry, Institut d’Optique Graduate School, Palaiseau (Frederic DRUON), CIMAP UMR6252 CNRS (Pavel LOIKO), IRCER UMR7315 CNRS, Limoges (Rémy BOULESTEIX), CORIA UMR6614 CNRS, Rouen (Ammar HIDEUR).

Lasers emitting in the mid-infrared (MIR) above 3 µm attract strong interest, as their emission matches spectral signatures of many atmospheric molecules and lies at the edge of a water absorption band. As a result, 3 µm lasers are important for applications in spectroscopy of greenhouse gases and hydrocarbons. The project aims to develop novel functional inorganic materials based on low-phonon-energy single crystals and transparent ceramics doped with Dy³⁺ ions, enabling emission beyond 3 µm, and to demonstrate their suitability for efficient, broadly tunable, and ultrashort-pulse MIR solid-state lasers. Various host matrices, including fluorite crystals and sesquioxide ceramics with high transparency in the 3 µm range, will be developed and spectroscopically characterized. Their integration into laser systems will involve the study of innovative pumping schemes, thermal management for high-power and high-repetition-rate operation, and dedicated architectures for ultrashort-pulse generation.