With the method of wavelet transform,we consider the temporal behaviour of high-order harmonic generation from one-dimensional H+2 exposed to an ultrashort laser pulse with a duration of tens of femtoseconds.The resul...With the method of wavelet transform,we consider the temporal behaviour of high-order harmonic generation from one-dimensional H+2 exposed to an ultrashort laser pulse with a duration of tens of femtoseconds.The results,which are calculated by numerically solving the corresponding time-dependent Schrödinger equation with the split-operator method in the non-Born-Oppenheimer approach,show that:(1)The high-order harmonics in the cut-off range emitted as a train of pulses have better coherence than those in the plateau.(2)The harmonics are emitted early in time when the intensity of laser pulse increases.展开更多
Using the one-demensional ion mode,We theoretically investigate the dynamics ionization process and the high-order harmonic generation of the He^(+)subject to different kinds of two-colour laser pulse with the same fu...Using the one-demensional ion mode,We theoretically investigate the dynamics ionization process and the high-order harmonic generation of the He^(+)subject to different kinds of two-colour laser pulse with the same fundamental frequency but various harmonic frequencies.It is found that from the results calculated by numerically solving the time-dependent Schrödinger equation,the two-colour laser pulse with the fundamental frequency and harmonic frequency enables the power spectrum of high-order harmonic generation to increase by a few orders of magnitude and the yield of He^(+)to enhance significantly when the harmonic frequency of laser pulse is close to the energy interval between the ground state and the first excited state of He^(+);even the harmonic field added into the pulse is much weaker than the fundamental one.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos.19974058 and 69925513the Chinese National Major Basic Research Project under Grant No.G1999075200.
文摘With the method of wavelet transform,we consider the temporal behaviour of high-order harmonic generation from one-dimensional H+2 exposed to an ultrashort laser pulse with a duration of tens of femtoseconds.The results,which are calculated by numerically solving the corresponding time-dependent Schrödinger equation with the split-operator method in the non-Born-Oppenheimer approach,show that:(1)The high-order harmonics in the cut-off range emitted as a train of pulses have better coherence than those in the plateau.(2)The harmonics are emitted early in time when the intensity of laser pulse increases.
基金Supported by the National Natural Science Foundation of China under Grant Nos.19974058 and 69925513the Chinese National Major Basic Research Project under Grant No.G1999075200.
文摘Using the one-demensional ion mode,We theoretically investigate the dynamics ionization process and the high-order harmonic generation of the He^(+)subject to different kinds of two-colour laser pulse with the same fundamental frequency but various harmonic frequencies.It is found that from the results calculated by numerically solving the time-dependent Schrödinger equation,the two-colour laser pulse with the fundamental frequency and harmonic frequency enables the power spectrum of high-order harmonic generation to increase by a few orders of magnitude and the yield of He^(+)to enhance significantly when the harmonic frequency of laser pulse is close to the energy interval between the ground state and the first excited state of He^(+);even the harmonic field added into the pulse is much weaker than the fundamental one.
