High Power Ytterbium-Doped Fiber Lasers Employing Longitudinal Vary Core Diameter Active Fibers

High peak power Ytterbium doped fiber amplifiers

1 Abstract We have tested a series of Ytterbium doped large core fibers operating near 10Kpps and producing pulses of approximately 1ns. We have achieved 850μJ/pulse resulting in peak powers in excess of 2MW with 0.4ns pulses and near diffraction limited beams. In another fiber, we have achieved over 1.5mJ/pulse with pulses of 900ps corresponding to 1.65MW of peak power and M of 2.5. In the lat...

High-Power and Tunable Operation of Erbium-Ytterbium Co-Doped Cladding-Pumped Fiber Lasers

We describe erbium-ytterbium co-doped fiber lasers in different free-running and tunable configurations. The lasers were cladding-pumped by high-power multimode diode sources. We compare pumping at 915 and 980 nm. With a free-running laser, we obtained slope efficiencies of up to 50% with 915-nm pumping and 38% with 980-nm pumping, with respect to absorbed pump power. We reached a double-ended ...

Thermo-optical effects in high-power ytterbium-doped fiber amplifiers.

We investigate the effect of temperature gradients in high-power Yb-doped fiber amplifiers by a numerical beam propagation model, which takes thermal effects into account in a self-consistent way. The thermally induced change in the refractive index of the fiber leads to a thermal lensing effect, which decreases the effective mode area. Furthermore, it is demonstrated that the thermal lensing e...

Characteristics of Q-Switched Cladding-Pumped Ytterbium-Doped Fiber Lasers with Different High-Energy Fiber Designs

We theoretically and experimentally analyze Q-switched cladding pumped ytterbium-doped fiber lasers designed for high pulse energies. We compare the extractable energy from two high-energy fiber designs: 1) singleor few-moded low-NA large mode area (LMA) fibers and 2) large-core multimode fibers, which may incorporate a fiber taper for brightness enhancement. Our results show that the pulse ene...

Advanced Optical Fibers for High Power Fiber Lasers