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Dipolar effects on ...
Dipolar effects on propagation of ultrashort laser pulse in one-dimensional para-nitroaniline (pNA) molecules
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Zhao, K. (author)
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Li, H. Y. (author)
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Liu, J. C. (author)
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Wang, C. K. (author)
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- Luo, Yi (author)
- KTH,Teoretisk kemi
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(creator_code:org_t)
- 2005-11-09
- 2005
- English.
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In: Journal of Physics B. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 38:23, s. 4235-4245
- Related links:
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https://urn.kb.se/re...
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https://doi.org/10.1...
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Abstract
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- The dynamic behaviour of ultrashort (femtosecond) laser pulses in a molecular medium is studied by solving the full Maxwell-Bloch equations beyond the limits of the slowly varying envelope approximation and the rotating-wave approximation under the resonant and the non-resonant conditions. A one-dimensional asymmetric charge-transfer molecule, para-nitroaniline, is used as a model molecule whose electronic properties are calculated with the time-dependent hybrid density functional theory. Under the one-photon resonant condition, 4 pi pulse is separated into two sub-pulses. The weight of the second-harmonic component mainly contributed by the two-photon excitation becomes stronger with longer propagation time. Under the two-photon resonant condition, the separation of 4 pi pulse is not induced and many higher-order spectral components beyond the second-harmonic generation occur. Interestingly, when the pulse propagates for long enough, the carrier modification becomes so significant that a continuous spectrum is generated. The Fourier transform of the high-harmonic spectrum demonstrates that an even shorter laser pulse can be produced in both resonant and non-resonant propagations. The effects of permanent dipole moments on the pulse evolution are discussed.
Keyword
- femtosecond optical pulses
- high-harmonic-generation
- 2-photon absorption
- attosecond pulses
- 2-level medium
- light
- media
- hyperpolarizability
- density
- moments
Publication and Content Type
- ref (subject category)
- art (subject category)
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