NKT Photonics has introduced a new version of its Crystal Fibre series double clad rod type fibre. The DC-200-85-Yb-ROD is made by Crystal Fibre airclad technology and features low photodarkening. The Ytterbium doped rod is typically used in output stages of amplifier chains for pulsed laser amplification.
The DC-200-85-Yb-ROD fibre features a 65µm mode field diameter Ytterbium core. The 200µm pump core diameter accepts pump light at numerical aperture values up to 0.54 for pumping at 915 or 976nm. Pump absorption is 30dB/m for 976 nm pumping.
The fibre is designed for OEM use for industrial customers. It could be used as an extension of output energy levels for existing fibre amplifiers or as a replacement to traditional crystalline rods such as Nd:YAG, Nd:YVO4, Nd:YLF etc. Compared to such traditional laser rods, the rod fibre offers high beam quality guidance of the signal as well as guidance of pump, and thermal lensing is not an issue. The rod fibre has a high single pass gain, high slope efficiency (~70 per cent) and pump absorption is polarisation independent.