Opt Lett. 2018 Nov 1;43(21):5275-5278. doi: 10.1364/OL.43.005275.
Spatially resolved interference is observed between high-order harmonics generated in two longitudinally separated gas targets. High-contrast modulations in the intensity of each harmonic order up to the cutoff are observed on-axis in the far field of the source as the separation between the gas targets is increased. For low-order harmonics, additional off-axis modulations are observed, which are attributed to the interference between the contributions from the long quantum trajectories from each gas target. The inherent synchronization of this setup offers the prospect for high-stability metrology of quantum states with ultrafast temporal resolutions.
在两个纵向分离的气体靶中产生的高次谐波之间观察到空间分辨干扰。随着气体靶之间的距离增加，在源的远场中，在每个谐波阶截止值以上观察到高强度的高对比度调制。对于低阶谐波，还观察到额外的离轴调制，这归因于来自每个气体靶的长量子轨迹的贡献之间的干涉。该设置的固有同步性为具有超快时间分辨率的量子态的高稳定性计量学提供了前景。
