Ultrashort Isolated Attosecond Pulse Generation with 750-nm Free-Carrier Envelope Phase Near-Infrared Pulses

作者：Xiaowei Wang, Fan Xiao, Jiacan Wang, Li Wang, Bin Zhang, Jinlei Liu, Jing Zhao, Zengxiu Zhao · 发表于：Ultrafast Science · 年份：2024 · DOI：10.34133/ultrafastscience.0080 · 被引用次数：43 · 研究领域：Laser-Matter Interactions and Applications、Advanced Fiber Laser Technologies、Spectroscopy Techniques in Biomedical and Chemical Research

Ultrashort laser pulses can serve as fast probes to record instant events. The isolated attosecond pulses (IAPs) generated from high-order harmonic generation (HHG) have been shortened down to about 2 atomic units in time, empowering us to study quantum behaviors of electrons in atoms, molecules, and solids with unprecedented time resolution. Following the cutoff energy law of HHG, the shortest IAP reported so far is driven with short-wavelength infrared (SWIR) pulses, which require additional broadband frequency conversion techniques and raise the bar for attosecond researches. Here, we show that with few-cycle near-infrared (NIR) laser pulses, IAP with pulse duration of 51 ± 4 as is generated during 1-fs linear polarization gate formed by generalized double optical gating (GDOG) technique. The characterization is done with attosecond streak camera, and phase reconstruction is performed with quick phase retrieval by omega oscillation filtering (qPROOF). Furthermore, we show that the IAP generation favors certain carrier envelope phases (CEPs) in the narrow gate, i.e., IAP is only efficiently produced for certain CEPs, which eliminates the requirement of CEP stabilization. The demonstrated scheme for IAP generation in principle has much higher conversion efficiency than the long-wave driver scheme according to the wavelength scaling law of HHG. Our work suggests an alternative way to generate ultrashort IAPs by applying GDOG on few-cycle free-CEP NIR driving pulses, and is th...