Gigawatt level, 10 fs high efficiency visible pulse generation

We present a robust approach capable of generating ultrashort pulses in the visible (VIS) spectral range through second-harmonic generation of broadened pulses centered at around 1030 nm. Tunable VIS pulses with durations as short as 10 fs, sub-20 fs, and sub-50 fs across the 420–600 nm range are achieved by spectrally broadening the 1030 nm output employing a dual-stage hollow-core fiber setup, followed by frequency doubling in cascaded beta barium borate (β-BaB2O4, BBO) crystals. The system delivers pulse energies ranging from a few to above hundred microjoules at repetition rates ranging between 10 and 100 kHz, while maintaining excellent beam quality and power stability over several hours of continuous operation. These characteristics make the source highly suitable for applications in ultrafast spectroscopy, nonlinear optics, and strong-field physics.