We experimentally observe longer than long trajectory influence in high order harmonic generation (HHG) by varying the peak intensity of the driving laser field through either direct attenuation, or by chirping the laser pulse. Using a theoretical Gaussian beam model to simulate spatial interference resulting from quantum path interference we show that the measured interference patterns cannot be solely explained by the well established short and long trajectories. The structure change is most prominent for the more divergent, off-axis components of the lower plateau harmonic region, affecting the direction and amplitude of the extreme ultraviolet light emitted, and is thus of importance for understanding and controlling the fundamentals of the HHG process.
High Harmonic Generation with Orbital Angular Momentum Beams: Beyond-dipole Corrections
Max Planck Institute for the Structure and Dynamics of Matter（马克斯·普朗克物质与结构动力学研究所）；Center for Free Electron Laser Science（自由电子激光科学中心）；Center for Computational Quantum Physics (CCQ)（计算量子物理中心）；The Flatiron Institute（_flatiron_研究所）
Quantum Trajectory Separation and Attosecond Mapping in Liquid High-Harmonic Generation
Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology（华中科技大学光电国家实验室和物理学院）；School of Mathematics and Physics, China University of Geosciences（中国地质大学数学与物理学院）；Hubei Key Laboratory of Optical Information and Pattern Recognition, Wuhan Institute of Technology（武汉工程大学湖北省光学信息与模式识别重点实验室）
Attosecond Path Qubits in High-Harmonic Generation: Classical Dephasing and Trace-Out Decoherence
Guangdong Technion - Israel Institute of Technology（广东以色列理工学院）；Technion – Israel Institute of Technology（以色列理工学院）；Eastern Institute of Technology（东方理工大学）
Quantum-enhanced second harmonic generation beyond the photon pairs regime
Institute of Photonics, Department of Physics, University of Strathclyde（斯特拉斯克莱德大学光子学研究所物理系）；Como Lake Institute of Photonics, Dipartimento di Scienza e Alta Tecnologia（科莫湖光子学研究所科学与技术系）；James Watt School of Engineering, University of Glasgow（格拉斯哥大学詹姆斯·瓦特工程学院）；School of Physics and Astronomy, University of Glasgow（格拉斯哥大学物理与天文学学院）；Istituto di Fotonica e Nanotecnologie del CNR（意大利国家研究委员会光子学与纳米技术研究所）
