Two-pulse orientation dynamics and high-harmonic spectroscopy of strongly-oriented molecules Kraus, P M Baykusheva, Denitsa Rangelova Wörner, H J Condensed Matter Physics Atomic and Molecular Physics and Optics We present the detailed analysis of a new two-pulse orientation scheme that achieves macroscopic field-free orientation at the high particle densities required for attosecond and high-harmonic spectroscopies (Kraus et al 2013 arXiv:1311.3923). Carbon monoxide molecules are oriented by combining one-colour and delayed two-colour non-resonant femtosecond laser pulses. High-harmonic generation is used to probe the oriented wave-packet dynamics and reveals that a very high degree of orientation (Nup/Ntotal = 0.73–0.82) is achieved. We further extend this approach to orienting carbonyl sulphide molecules. We show that the present two-pulse scheme selectively enhances orientation created by the hyperpolarizability interaction whereas the ionization-depletion mechanism plays no role. We further control and optimize orientation through the delay between the one- and two-colour pump pulses. Finally, we demonstrate a complementary encoding of electronic-structure features, such as shape resonances, in the even- and odd-harmonic spectrum. The achieved progress makes two-pulse field-free orientation an attractive tool for a broad class of time-resolved measurements. IOP Publishing 2014 info:eu-repo/semantics/article doc-type:article text http://purl.org/coar/resource_type/c_2df8fbb1 https://research-explorer.ista.ac.at/record/14021 Kraus PM, Baykusheva DR, Wörner HJ. Two-pulse orientation dynamics and high-harmonic spectroscopy of strongly-oriented molecules. <i>Journal of Physics B: Atomic, Molecular and Optical Physics</i>. 2014;47(12). doi:<a href="https://doi.org/10.1088/0953-4075/47/12/124030">10.1088/0953-4075/47/12/124030</a> eng info:eu-repo/semantics/altIdentifier/doi/10.1088/0953-4075/47/12/124030 info:eu-repo/semantics/altIdentifier/issn/0953-4075 info:eu-repo/semantics/altIdentifier/e-issn/1361-6455 info:eu-repo/semantics/altIdentifier/arxiv/1311.3923 info:eu-repo/semantics/openAccess