A tapered fused bundle in which several multimode pump fibers, for example 6 or 18 around a central signal fiber, are fused and drawn down to match the inner cladding of double-clad fiber. Pump brightness is conserved, so the taper must respect the NA limits or light leaks out as heat. Combiners with a signal feedthrough let the laser light pass through the center while pump enters around it.
Combiner case is at 60 degrees at full pump, there's leakage at the taper, check the pump fiber NA against the spec.
Also heard as
- tapered fiber bundle
- TFB
Related terms
Double-clad fiber
Fiber with a small doped core for the laser light inside a much larger inner cladding that guides multimode pump light.
Pump
The energy source that excites a gain medium, or the act of supplying it, usually with diodes, flashlamps or current.
Fiber laser
A laser whose gain medium is an optical fiber with a rare-earth-doped core, pumped by diodes.
Laser diode
A semiconductor laser driven by electric current, used as a light source in its own right and to pump other lasers.