Linearly polarized pulsed Yb fiber laser with 20 ns pulse width and 70 GHz spectral linewidth at 1083 nm

A low-birefringence 5-m-long fiber amplifier with a highly Yb-doped 40-μm, 0.028-NA phosphosilicate core produces linearly polarized (7.2-dB PER) 20-ns, 0.8-mJ pulses with 69-GHz linewidth, M2 = 1.2, and 120 W of average output power at 1083 nm.