Modeling of transverse mode interaction in large-mode-area fiber amplifiers

Power Scaling Fiber Amplifiers Using Very-large-mode-area Fibers

Transverse Modes in Large-Mode-Area Fibers

This thesis is devoted to the study of transverse modes in large-mode-area (LMA) fibers. It highlights the importance of transverse spatial-hole burning (TSHB) effect in LMA multimode fibers through experiments and simulations. The measured beam-quality factor decreases until the gain becomes saturated in an amplified spontaneous emission (ASE) source based on an Yb-doped LMA multimode fiber. A...

High-energy single-transverse-mode Q-switched fiber laser based on a multimode large-mode-area erbium-doped fiber.

We demonstrate that appropriately designed doped multimode fibers provide robust single-mode output when used within a fiber laser cavity. Using a novel large-mode-area fiber, we demonstrate what we believe to be record single-mode (M(2) <1.2) pulse energies of >0.5 mJ from a Q -switched fiber laser and even higher pulse energies (as high as 0.85 mJ) with slightly compromised spatial-mode quali...

Steady-periodic method for modeling mode instability in fiber amplifiers.

We present a detailed description of the methods used in our model of mode instability in high-power, rare earth-doped, large-mode-area fiber amplifiers. Our model assumes steady-periodic behavior, so it is appropriate to operation after turn on transients have dissipated. It can be adapted to transient cases as well. We describe our algorithm, which includes propagation of the signal field by ...

Mode competition in high power fiber amplifiers.

Using a beam propagation model of Yb3+ doped, CW fiber amplifiers we show that gain saturation by a strong fundamental mode significantly suppresses the growth of higher order modes with parallel polarization, but enhances the growth of higher order modes with perpendicular polarization. We quantify this effect in straight and bent fibers, with full core or restricted area doping.