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LMA-TDF-25/250

Eye Safe 25/250 Thulium-Doped LMA Double Clad Fiber

The first true LMA fiber featuring a unique low NA (0.1) high concentration Tm-doped core design. It is fully optimized for high slope efficiency (composition has demonstrated >130% quantum efficiency) when pumped at 793nm. This extraordinary efficiency is due to composition enabled cross relaxation of Thulium ions in the core. The high Tm-concentration allows short device lengths and high pump conversion efficiency while the low NA (few moded) core design is ideal for applications where robust single-mode beam quality is critical. The high NA (0.46) 250μm pump cladding waveguide allows for efficient coupling of high pump powers. The large core diameter (25μm) maintains a large mode field diameter and short device length thereby minimizing non-linear effects such as SBS and SRS.
Applications
  • Eye Safe (~2µm) lasers and amplifiers
  • Military and commercial lidar
  • ~2µm outpost TEM00 fiber lasers for pumping solid state crystal lasers
  • High peak power pulsed fiber amplifiers
Features & Benefits
  • Unique low NA Tm-doped core design — Robust single-mode beam quality
  • Optimized composition for 793nm pumping — Very high conversion efficiency
  • High pump absorption — Short fiber length, efficient lasing in the ~2µm λ window

Optical Specifications

Operating Wavelength (nominal)2000 nm
Cladding Absorption5 dB/m @ 793 nm (nominal)
1 ± 0.2 dB/m @ 1180 nm
Core Numerical Aperture (nominal)0.10
Cladding Numerical Aperture (nominal)0.46

Geometrical & Mechanical Specifications

Core Diameter25.0 ± 3.0 µm
Clad Diameter250.0 ± 10.0 µm
Coating Diameter400 ± 25 µm
Outer Cladding MaterialLow Index Polymer
Proof Test Level≥ 100 kpsi (0.7 GN/m2)

Note: Perfectly matched passive versions are available for many of our active fibers.
See our Component and Delivery Fibers cheat sheet. (PDF)

RoHS Compliant