nLight has introduced highly doped, photodarkening resistant ytterbium fibres, featuring absorption at 920nm up to 60 per cent higher than conventional fibres, and pump conversion efficiencies routinely over 75 per cent.
In 2005, the fibre division of nLight, previously Liekki Corporation, was the first active-fibre manufacturer to publish techniques for efficiently measuring and mitigating photodarkening with its direct nanoparticle deposition (DND) fibre production technology. This effort has continued unabated and resulted in new fibre designs and processes to further reduce the detrimental effects of photodarkening.
The large mode area (LMA), low numerical aperture (NA) fibres offered by nLight exhibit a five-fold decrease in loss under accelerated stress testing conditions. The loss of LMA, high NA fibres is even below the measurement capability of the accelerated test.
The new photodarkening resistant Liekki ytterbium fibres are available in core/clad geometries ranging from 7/125µm to 30/250µm, in non-polarisation and polarisation maintaining versions.