LIEKKI Introduces High-Efficiency, Large Mode Area (LMA) Erbium Fiber Family

Lohja, Finland  May 18, 2006

LIEKKI, a leading supplier of highly doped optical fibers, has developed a new large mode area erbium double clad fiber.

LIEKKI blazes new ground with a highly-doped erbium double clad (Er-DC), large mode area (LMA) fiber, LIEKKI™ Er60-20/125DC. This fiber features high erbium concentration for efficient absorption, large 20 μm core with low NA of 0.07 supporting good beam quality, and 125 μm octagonal-shaped cladding for ease of use. The fiber demonstrates >30% slope efficiency with 980 nm pumping with efficient lasing bandwidth extending up to 1.6 μm.

Mikko Söderlund, Fiber Product Manager, says “LIEKKI™ Er60-20/125DC clearly demonstrates the capabilities and quality of the DND technology – this fiber features high concentration, large core/clad ratio, low clustering and low background losses, a combination which is unreachable with conventional processes. It opens up completely new possibilites in the eye-safe wavelength region. We are excited about this first release of the Er-DC product family and look forward to further leverage and develop this core platform into other core/clad ratios and variants like polarization maintaining and all-glass fibers, following our customer’s requirements”.

LIEKKI™ Er60-20/125DC opens many applications in the 1.5 - 1.6 μm region

• Eye-safe fiber lasers and amplifiers

• Military and commercial lidar

• Single frequency fiber lasers

• High peak power amplifiers

• Ultra-short pulse amplifiers

• Industrial machining

• Medical imaging

The direct Er-doping approach avoids some of the commonly known trade-off’s of Er:Yb co-doped fibers like poor/unrepeatable efficiency, high core NA and spurious lasing at 1 μm. The fiber can be pumped either with 980 nm or 1480 nm. LIEKKI also provides 6 x 1:1 pump combiner for this fiber.