Optical fibre doped with YPO4:Pr3+ nanocrystals - glass powder doping technique for new laser transitions

Rare-earth-doped optical fibres had a tremendous impact on the telecom as well as the laser market. However, these silica-based fibres are limited to a relatively small number of laser transitions near 1µm (Yb, Nd), 1.5µm (Er), and 2µm (Tm, Ho). Fluoride and chalcogenide glass fibres are promising candidates to extend the emission to new spectral regions, but they have a rather low temperature stability and splicing to other fibres still has issues. Other oxide host materials could play an important role but standard silica technology is rather limited in material composition. Nanoparticle (NP) doping can overcome this limitation [1,2] and crystalline NPs could even address application beyond lasers by providing optical properties not present in amorphous materials. However, so far the direct doping of fibre preforms with active nanocrystals (ANCs) has mostly resulted in their dissolution [3]. To the best of our knowledge, we presents an optical fibre where the ANCs have survived the fibre drawing process using the glass powder doping technology, demonstrating a path towards new laser transitions and functionality in oxide-based fibres.