image: (a) Experimental schematic and (b) measured unique photoelectron holography from molecular nitrogen. The intercycle interference effect was substantially suppressed when utilizing near-single-cycle Vis/NIR laser pulses, allowing the observation of two distinct holographic patterns (spider-leg-like (dashed curve) and fishbone-like (dash-dotted lines)) in a single-measurement setup. The observed holographic pattern contains a wealth of information, including the Gouy phase effect on rescattering electron wavepackets and the internuclear separation of the target molecule.
Credit: by Tsendsuren Khurelbaatar, Xuanyang Lai, Dong Eon Kim
Scientists Unveil Fundamental Electron-holograms for Ultrafast imaging of Atoms and Molecules
A team of scientists led by Professor Dong Eon Kim at the Pohang University of Science and Technology and Professor X. Lai at the Innovation Academy for Precision Measurement Science and Technology achieved a breakthrough in ultrafast imaging by separately and clearly observing two distinct holographic patterns, spider-leg- and fishbone-like, for the first time. They utilized near-single-cycle laser pulses not only to unveil and identify spider-leg-like and fishbone-like patterns, but also the Gouy phase effect on the electron hologram. This study opens an avenue for correctly extracting the internuclear separation of a target molecule from a holographic pattern.
Traditional imaging methods, such as X-ray diffraction, have limitations in capturing the rapid movement of electrons within molecules. This new approach, based on strong-field photoelectron holography (SFPH), promises to revolutionize our understanding of these fundamental building blocks with an unprecedented resolution. By using carrier-envelope-phase-controlled, near-single-cycle laser pulses, the team was able to clearly visualize and identify distinct holographic patterns, revealing details of electron dynamics within a target molecule because inter-cycle interference patterns that had previously hampered SFPH measurements were suppressed. "For the first time, these patterns have been directly observed," explained Professor Kim.
"Our approach allows us to control electron behavior on an attosecond timescale [an attosecond is a billionth of a billionth of a second]."
The researchers demonstrated the power of their method by extracting structural information about the target molecule. The results find applications in fields ranging from chemistry and biology to materials science.
Simplified Approach, Exciting Possibilities
Importantly, this new approach is simpler than previous methods that often require multiple measurements. This advancement is versatile, with the potential to be combined with other techniques to provide even more precise control and insights.
"Our work opens up exciting avenues for studying molecular dynamics and controlling chemical reactions," remarked Professor Kim.
Journal
Light Science & Applications