High peak power single frequency pulses using a short polarization- maintaining phosphate glass fiber with a large core

We report a high power, single frequency 1.5 μm pulsed fiber master oscillator-power amplifier laser source using a large core, polarization- maintaining phosphate glass fiber. The phosphate glass fiber produces high powers with low nonlinearities using high Er-Yb codoping and short length. Using this fiber, we were able to generate single frequency pulses with peak powers up to 51.5 kW. This is the highest reported peak pulse power for eye safe single frequency fiber laser systems.