Year: 2026
Type: article
Abstract: The mid-infrared (MIR) spectral region is an attractive band for major applications, such as spectroscopy owing to the presence of many molecular absorption signatures. Fiber lasers operating in this spectral region are highly sought after because of their compactness and ease of integration into detection systems. Considerable effort has been invested in advancing the ultrafast operation of such lasers, particularly in the 3 μm spectral range where erbium ions exhibit broadband gain under 976 nm pumping. However, achieving passively mode-locked femtosecond operation with erbium fiber oscillators remains challenging due to the complexities involved in designing saturable absorbers, particularly with adapted carrier recovery time. In this study, we present a compact setup for the sub-picosecond operation of an erbium fluoride fiber laser. The passive mode-locking operation is enabled by a graphene film on a gold mirror fabricated in-lab using a wet chemical transfer process. The laser produced a record pulse duration of 656 fs at 2.8 μm and delivered energies of up to 4.93 nJ. This work explores the soliton dynamic operation of the laser and paves the way for the further development of such MIR femtosecond fiber oscillators.
Source: APL Photonics
DOI: 10.1063/5.0342329
Institutions: Centre National de la Recherche Scientifique, Complexe de Recherche Interprofessionnel en Aérothermochimie, Université de Rouen Normandie, Institut National des Sciences Appliquées Rouen Normandie, Université Sorbonne Paris Nord, Laboratoire de physique des lasers, École Nationale Supérieure d'Ingénieurs de Caen, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Centre de Recherche sur les Ions, les Matériaux et la Photonique, Université de Caen Normandie
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,750
Awards: G1096158024, G1928654118, Mid-IR Saturable Absorber Mirrors for Fiber-based Frequency Combs, G3010527862, G3228564310, G3573499714, G4143429399, Short pulse solid state Lasers and amplifiers Beyond 2 µm, G6353114084, G6863221862, G697885514, G7080048889, G7240651115, G7376787254, WelcomINg and TraiNING of international high-level post-docs in Normandy, G8354177389
OpenAlex ID: W7202353011