  We demonstrate a remarkably effective single-stage compression technique for
ultrafast pulses in the visible electromagnetic spectrum using second-harmonic
pulses at 515 nmderived from a 1030 nm Yb-based femtosecond regenerative
amplifier. By employing an advanced multi-plate scheme, we achieve more than
fourfold compression from 180 fs to 40 fs with an extremely high spectral
broadening efficiency of over 95%, and a temporal compression efficiency
exceeding 75%. In addition, our method leverages a low nonlinearity medium to
attain the shortest pulse durations for a single compressor while maintaining a
superb spatial beam quality with 97% of the energy confined in the main lobe of
the Arie disk. Moreover, our technique enhances the temporal pulse quality at
515 nm without generating substantial femtosecond-to-picosecond pulse
pedestals. The resulting intense visible laser pulses with excellent
spatio-temporal parameters and high repetition rate of 100 kHz to 1 MHz open up
new frontiers for extreme nonlinear optics and ultrabright EUV and X-ray
high-harmonic generation using short VIS wavelength.

Optics