Kansai Institute for Photon Science　| 【on-site】The 118th KPSI Seminar｜Direct Generation of Bright Isolated Attosecond Pulses from Post-Compressed Yb Lasers

Professor   Ming-Chang CHEN

Institute of Photonics and Technologies, National Tsing Hua University 

Abstract

Attosecond science enables direct observation of electron dynamics, but current isolated attosecond pulse (IAP) sources are limited by photon flux and scalability. Here, we present a new approach to generating bright IAPs driven by post-compressed ytterbium (Yb) lasers. Using advanced post-compression techniques, long Yb pulses are compressed to the few-cycle regime, enabling direct high-order harmonic generation (HHG). In particular, cascaded focus-and-compression schemes allow large nonlinear phase accumulation while preserving beam quality. We further show that filamentation in a semi-infinite gas cell induces spatiotemporal reshaping of the driving pulse, including self-compression and self-guiding, leading to enhanced phase-matching gating and the generation of bright, high-contrast IAPs. This approach provides a scalable route to high-flux attosecond sources, opening opportunities for ultrafast spectroscopy, coherent soft X-ray science, and precision metrology.