All-PM fiber 1.0-μm 127-fs pulse dispersive wave generation from a 1.5-μm GHz fundamental-repetition-rate femtosecond fiber laser.

We report the generation of a 1.0- and 1.5-µm GHz fundamental-repetition-rate femtosecond fiber (GHz-FFF) laser system in an all-polarization-maintaining (PM) fiber laser configuration. The coherence of the nonlinear conversion from the 1.5-µm wavelength is guaranteed by the sub-100-fs incident pulse duration and optimization of the length of the PM highly nonlinear fiber (i.e., only 16 cm long). This coherent property of the GHz-FFF pulses is experimentally quantified by single-shot spectroscopy. The all-PM GHz-FFF laser system with good long-term stability offers outstanding performance metrics at 1.0 µm, i.e., 25.5-nm bandwidth and 127-fs pulsewidth. This novel design presents an excellent alternative for offset-free optical frequency comb generation, sub-cycle pulse generation, label-free microscopy, etc.