Successful development of fiedable laser systems is expected to have a vast impact for future directed energy (DE) applications. Consequently, fiber lasers offer several advantages over bulk solid state and chemical lasers including: compactness, high output efficiencies, and minimal free space optics. In addition, due to their inherent geometry (large surface area to volume ratio), fibers have excellent capacity for heat dissipation; alleviating thermal management and beam distortion challenges associated with high average power bulk solid-state lasers. As such, significant advances in high average power 1µm and 2µm fiber lasers have been achieved, in both continuous wave (CW) fiber lasers and ultrashort pulse fiber lasers.

Despite their advantages and brisk development, in terms of pulse energy storage and extraction, fiber lasers lag bulk solid-state lasers. This is due to the small fiber core (10s of microns) geometries of commercial single-mode and large mode area fibers, which also induce nonlinear optical effects when power scaling to high peak powers. To that end, we aim to research novel high energy, high peak power pulse fiber lasers with long pulse widths. In contrast to ultrashort pulse fiber lasers with picosecond and below pulse widths we aim to explore longer pulse width fiber lasers, on the order of nanoseconds to hundreds of nanoseconds. Consequently, we aim to research nonlinear suppression schemes or novel fiber designs to mitigate nonlinear effects such as Stimulated Brillouin Scattering, Stimulated Raman Scattering, Kerr nonlinearities, etc; which are expected at high energies and powers. In addition, for wavelengths in the anomalous dispersion regime, we endeavor to explore dispersion compensation techniques or designs to mitigate nonlinear effects such as modulation instability. Overall, pulse fiber lasers capable of producing high pulse energies are desired for potential LIDAR or remote sensing applications.