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

Lohja - Liekki, a supplier of highly doped optical fibers, has developed a new LMA erbium double clad fiber.

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

Mikko Söderlund, Fiber Product Manager, says "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".

Er60-20/125DC opens many applications in the 1.5-1.6µm 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 1µm. The fiber can be pumped either with 980nm or 1480nm. Liekki also provides 6 x 1:1 pump combiner for this fiber.

SOURCE: Liekki Corporation