Macroscopic study and control of high-order harmonic and attosecond pulse generation in noble gases

In this paper, the waveform control of high-order harmonic generation and attosecond pulse generation from a different initial state of He atom has been investigated. The results show that (i) by properly controlling the carrier-envelope phases, the time delays and the laser intensities of a 3-color laser pulse, the best waveforms for the harmonic cut-off extension can be found. Although the harmonic cut-offs from the ground initial state and the superposition initial state are almost the same, the harmonic intensities from the superposition initial state are 4 to 5 orders of magnitudes higher than those from the ground initial state. (ii) With the introduction of the inhomogeneous effect, the harmonic cut-offs can be further extended. However, the harmonic intensities from the superposition initial state are remarkably decreased compared with those from the homogeneous pulses, which is unbeneficial to generate the intense attosecond pulses. (iii) When the ground state is chosen to be the initial and with the assistance of the 4th UV pulse, not only the larger harmonic cut-offs can be obtained, but also the stronger harmonic plateaus can be found, which is favorable for producing the intense attosecond pulses. Thus, at the end of this paper, by superposing the harmonics from the best harmonic spectra, the single attosecond pulses with the duration of 36 as can be obtained.

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Attosecond-resolution molecular high-order harmonic emission and isolated attosecond pulse generation from H 2 +

Optics Communications ◽

10.1016/j.optcom.2016.12.048 ◽

2017 ◽

Vol 389 ◽

pp. 144-149 ◽

Cited By ~ 16

Author(s):

Liqiang Feng ◽

Hang Liu

Keyword(s):

Pulse Generation ◽

Attosecond Pulse ◽

High Order ◽

Harmonic Emission ◽

High Order Harmonic ◽

Isolated Attosecond Pulse ◽

Attosecond Pulse Generation

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High-intensity attosecond pulse generation by using inhomogeneous laser field in frequency and space

Journal of Nonlinear Optical Physics & Materials ◽

10.1142/s0218863517500345 ◽

2017 ◽

Vol 26 (03) ◽

pp. 1750034 ◽

Cited By ~ 5

Author(s):

Liqiang Feng ◽

Wenliang Li ◽

Rich-Samuel Castle ◽

Yi Li

Keyword(s):

Frequency Modulation ◽

High Intensity ◽

Laser Field ◽

Pulse Generation ◽

Attosecond Pulse ◽

High Order ◽

Inhomogeneous Field ◽

High Order Harmonic ◽

Attosecond Pulse Generation ◽

Space Modulation

High-order harmonic spectra and attosecond source generation from Ar atom driven by the inhomogeneous laser field in frequency and space have been theoretically investigated. The results showed that (i) for the case of the frequency modulation of the laser, the harmonic cutoff can be remarkably extended with the introduction of the chirp of the laser field, (ii) for the case of the space modulation of the laser, the harmonic cutoff can be further extended by using the positive spatial inhomogeneous field, (iii) by properly adding a terahertz controlling field, the intensity of the harmonic yield can be enhanced by 2 orders of magnitude, showing a 775[Formula: see text]eV supercontinuum. As a result, five isolated attosecond pulses (IAPs) from 60 as to 22 as can be obtained.

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