Single-shot reconstruction of a subpicosecond pulse from a fiber laser system via processing strongly self-phase modulated spectra

•Single-shot 1-μJ pulse from a fiber system is measured by a simple method.•0.7-ps pulse without time direction ambiguity is retrieved from SPM spectra.•This is the first single-shot pulse reconstruction for fiber laser systems by this method. The single-shot reconstruction of an ultrashort pulse from a fiber laser system by the method based on recording and numerical processing of two self-phase modulated spectra after a nonlinear fiber is demonstrated experimentally. The 0.7-ps asymmetrical signal with an energy of ~1 μJ retrieved by this method without time direction ambiguity is in good agreement with independent measurements by second harmonic generation frequency-resolved optical gating (SHG FROG) technique.