A laser built from meters of fiber whose core is doped with ytterbium, erbium or thulium, with fiber Bragg gratings or a seed and amplifiers in place of bulk mirrors. The long thin geometry spreads heat, so single-mode output reaches kilowatts and multimode industrial lasers tens of kilowatts with excellent efficiency. Yb fiber lasers around 1070 nm dominate cutting and welding; erbium covers the telecom band and thulium the 2 µm region.
The 6 kW fiber laser runs rings around the old CO2 on thin stainless, and there are no beam-path mirrors to align.
Also heard as
- fibre laser
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.
Fiber Bragg grating
A periodic index pattern written into a fiber core that reflects a narrow band of wavelengths and passes the rest.
MOPA
Master Oscillator Power Amplifier: a low-power seed laser followed by amplifier stages that bring it to full power.
Photodarkening
A slow, permanent rise in background loss in rare-earth-doped fiber under pumping, which erodes output power.
Pump combiner
A fused fiber component that merges the outputs of many pump diodes into the inner cladding of a double-clad fiber.