High Repetition Rate and High Energy Ultrashort Laser Pulse: The Next Light Source for Attosecond Spectroscopy

The ultrashort femtosecond laser pulse techniques in Ti:Sapphire laser systems advanced the development of attosecond pulse generation and associated attosecond metrology in probing attosecond time-resolved electron motion in atoms, molecules, and condensed matter. However, the limitation of its average power, repetition rate, and pulse energy leads to a bottleneck in developing high-flux and high-energy attosecond light sources. The recent breakthroughs in nonlinear spectral broadening have unlocked the potential for extending Yb-doped lasers to generate high-flux and high-repetition-rate attosecond extreme ultraviolet (EUV) pulses. Here, we briefly summarized the development of postpulse compression methods of the multithin plate (MTP) and multipass cell (MPC), which have shown significant advancements in achieving a high-average-power ultrafast laser. The advanced ultrafast light sources provide more choices on the applications for fundamental research within extreme temporal and spectral scales, of which the advantages are paving the way for novel discoveries in ultrafast science and promoting the research in attosecond coincidence spectroscopy, tabletop attosecond soft X-ray spectroscopy, and attosecond EUV nanoimaging and, consequently, opening the avenue to realize a breakthrough in zeptosecond time resolution and even zeptosecond pulse generation.