High-harmonic spectroscopy can access structural and dynamical information on molecular systems encoded in the amplitude and phase of high-harmonic generation(HHG)signals.However,measurement of the harmonic phase is a...High-harmonic spectroscopy can access structural and dynamical information on molecular systems encoded in the amplitude and phase of high-harmonic generation(HHG)signals.However,measurement of the harmonic phase is a daunting task.Here,we present a precise measurement of HHG phase difference between two isotopes of molecular hydrogen using the advanced extreme-ultraviolet(XUV)Gouy phase interferometer.The measured phase difference is about 200 mrad,corresponding to~3 attoseconds(1 as=10−18 s)time delay which is nearly independent of harmonic order.The measurements agree very well with numerical calculations of a four-dimensional time-dependent Schödinger equation.Numerical simulations also reveal the effects of molecular orientation and intramolecular two-center interference on the measured phase difference.This technique opens a new avenue for measuring the phase of harmonic emission for different atoms and molecules.Together with isomeric or isotopic comparisons,it also enables the observation of subtle effects of molecular structures and nuclear motion on electron dynamics in strong laser fields.展开更多
The interactions of strong-field few-cycle laser pulses with metastable states of noble gas atoms are examined. Metastable noble gas atoms offer a combination of low ionization potential and a relatively simple atomic...The interactions of strong-field few-cycle laser pulses with metastable states of noble gas atoms are examined. Metastable noble gas atoms offer a combination of low ionization potential and a relatively simple atomic structure, making them excellent targets for examining ionization dynamics in varying experimental conditions. A review of the current work performed on metastable noble gas atoms is presented.展开更多
基金Australian Research Council(LP140100813 and DP190101145)Griffith University.M.M.was supported by a Griffith University International Postgraduate Research Scholarship(GUIPRS)+3 种基金Griffith University Postgraduate Research Scholarship(GUPRS).Theoretical work was supported by the National Key R&D Program of China(Nos.2018YFA0404802 and 2018YFA0306303)Innovation Program of Shanghai Municipal Education Commission(2017-01-07-00-02-E00034)National Natural Science Foundation of China(NSFC)(Grant Nos.11574205,91850203,and 12204308)and Shanghai Science and Technology Commission(Grants No.22ZR1444100).
文摘High-harmonic spectroscopy can access structural and dynamical information on molecular systems encoded in the amplitude and phase of high-harmonic generation(HHG)signals.However,measurement of the harmonic phase is a daunting task.Here,we present a precise measurement of HHG phase difference between two isotopes of molecular hydrogen using the advanced extreme-ultraviolet(XUV)Gouy phase interferometer.The measured phase difference is about 200 mrad,corresponding to~3 attoseconds(1 as=10−18 s)time delay which is nearly independent of harmonic order.The measurements agree very well with numerical calculations of a four-dimensional time-dependent Schödinger equation.Numerical simulations also reveal the effects of molecular orientation and intramolecular two-center interference on the measured phase difference.This technique opens a new avenue for measuring the phase of harmonic emission for different atoms and molecules.Together with isomeric or isotopic comparisons,it also enables the observation of subtle effects of molecular structures and nuclear motion on electron dynamics in strong laser fields.
文摘The interactions of strong-field few-cycle laser pulses with metastable states of noble gas atoms are examined. Metastable noble gas atoms offer a combination of low ionization potential and a relatively simple atomic structure, making them excellent targets for examining ionization dynamics in varying experimental conditions. A review of the current work performed on metastable noble gas atoms is presented.
