2026-09-15T08:33:09Zhttps://gredos.usal.es/oai/request

oai:gredos.usal.es:10366/1470192025-04-30T20:35:17Zcom_10366_133237com_10366_4512com_10366_3823col_10366_133238

00925njm 22002777a 4500 dc Chang, Kuang-Yu author Huang, Long-Cheng author Asaga, Koji author Tsai, Ming-Shian author Rego Cabezas, Laura author Huang, Pei-Chi author Mashiko, Hiroki author Oguri, Katsuya author Hernández García, Carlos author Chen, Ming-Chang author 2020-11 Polarization engineering and characterization of coherent high-frequency radiation are essential to investigate and control the symmetry properties of light–matter interaction phenomena at their most fundamental scales. This work demonstrates that polarization control and characterization of high-harmonic generation provides an excellent ellipsometry tool that can fully retrieve both the amplitude and phase of a strong-field-driven dipole response. The polarization control of high-harmonic generation is realized by a transient nonlinear dipole grating coherently induced by two noncollinear counterrotating laser fields.By adjusting the ellipticity of the two driving pulses simultaneously, the polarization state of every high-harmonic order can be tuned from linear to highly elliptical, and it is fully characterized through an energy-resolved extreme ultraviolet polarimeter. From the analysis of the polarization state, the ellipsometry indicated that both the amplitude and phase of the high-harmonic dipole scale rapidly with the driving laser field for higher-order harmonics, and, especially, for gases with a small ionization potential. Our experimental results were corroborated by theoretical simulations. Our findings revealed a novel high-harmonic ellipsometry technique that can be used for the next generation of high-harmonic spectroscopy and attosecond metrology studies because of its ability to provide single-digit attosecond accuracy.Our work also paves the way to precisely quantify the strong-field dynamics of fundamental processes associated with the transfer of energy and angular momentum between electron/spin systems and the symmetry-dependent properties of molecules and materials. K. Chang, L. Huang, K. Asaga, M. Tsai, L. Rego, P. Huang, H. Mashiko, K. Oguri, C. Hernández-García, and M. Chen, "High-order Nonlinear Dipole Response Characterized by Extreme-Ultraviolet Ellipsometry," in OSA High-brightness Sources and Light-driven Interactions Congress 2020 (EUVXRAY, HILAS, MICS), L. Assoufid, P. Naulleau, M. Couprie, T. Ishikawa, J. Rocca, C. Haefner, G. Sansone, T. Metzger, F. Quéré, M. Ebrahim-Zadeh, A. Helmy, F. Laurell, and G. Leo, eds., OSA Technical Digest (Optical Society of America, 2020), paper HF2B.5. http://hdl.handle.net/10366/147019 10.1364/HILAS.2020.HF2B.5 Attosecond pulses Ellipsometry Fundamental processes High harmonic generation Photon counting Polarization control High-order Nonlinear Dipole Response Characterized by Extreme-Ultraviolet Ellipsometry