Controlling continuum wavepacket interference by two-color laser field in over-the-barrier ionization regime

Abstract

Continuum wavepacket interference is investigated by numerically solving the time-dependent Schröodinger equation for the interaction of hydrogen atoms with laser fields. The obtained wavepacket evolution indicates that, in the over-the-barrier ionization regime (10¹⁶ W/cm²), the continuum–continuum (CC) interference of ionizing electrons becomes the main process in highorder harmonics generation (HHG), compared with continuum-bound (CB) transition, as reported by Kohler et al. [Phys. Rev. Lett. 105(20), 203902 (2010)].We propose a two-color laser field scheme for controlling the quantum trajectories of ionizing electrons and for extending the CC harmonic energy. As a result, a high energy platform occurs in the HHG spectrum, which entirely originates from the CC harmonics, with a cutoff adjustable by the relative phase of the two-color fields. This provides further understanding of the dynamic feature of atoms and molecules in super intense laser fields and provides an opportunity to image the atomic or molecular potential.

Keywords

continuum–continuum interference / high-order harmonic generation / over-the-barrier ionization

References

[1] C.Winterfeldt, C.Spielmann , and G.Gerber, Colloquium: Optimal control of high-harmonic generation, Rev. Mod. Phys. 80(1), 117 (2008)

[2] J.Itatani, J.Levesque , D.Zeidler, H.Niikura, H.Pépin, J. C.Kieffer, P. B.Corkum, and D. M.Villeneuve, Tomographic imaging of molecular orbitals, Nature 432(7019), 867 (2004)

[3] P. B.Corkum, Plasma perspective on strong field multiphoton ionization, Phys. Rev. Lett. 71(13), 1994 (1993)

[4] M.Lewenstein, P.Balcou , M. Yu.Ivanov, A.L’Huillier, and P. B.Corkum, Theory of high-harmonic generation by low-frequency laser fields, Phys. Rev. A 49(3), 2117 (1994)

[5] P.Moreno, L.Plaja , V.Malyshev, and L.Roso, Influence of barrier suppression in high-order harmonic generation, Phys. Rev. A 51(6), 4746 (1995)

[6] V. V.Strelkov, A. F.Sterjantov , N. Y.Shubin, and V. T.Platonenko , XUV generation with several-cycle laser pulse in barrier-suppression regime, J. Phys. At. Mol. Opt. Phys. 39(3), 577 (2006)

[7] J.Vazquez de Aldana and L.Roso, Magnetic-field effect in atomic ionization by intense laser fields, Opt. Express 5(7), 144 (1999)

[8] J. A.Pérez-Hernéndez, L.Roso, A.Zaïr, and L.Plaja, Valley in the efficiency of the high-order harmonic yield at ultra-high laser intensities, Opt. Express 19(20), 19430 (2011)

[9] D.Guo, C.Yu, J.Zhang, J.Gao, Z.Sun, and Z.Sun, On the cutoff law of laser induced high harmonic spectra, Front. Phys. 10(2), 103201 (2015)

[10] C.Yu, J.Zhang, Z.Sun, Z.Sun, and D.Guo, A nonperturbative quantum electrodynamic approach to the theory of laser induced high harmonic generation, Front. Phys. 10(4), 103202 (2015)

[11] M. C.Kohler, C.Ott, P.Raith, R.Heck, I.Schlegel, C. H.Keitel, and T.Pfeifer, High harmonic generation via continuum wave-packet interferenc, Phys. Rev. Lett. 105(20), 203902 (2010)

[12] X.Zhou and B.Li, Contribution of the bound states and continuum states of an atom in intense laser fields to high harmonic generation, Acta Physica Sinica 50(10), 1902 (2001) (in Chinese)

[13] M. D.Feit, J. A. Jr Fleck, and A.Steiger, Solution of the Schrödinger equation by a spectral method, J. Comput. Phys. 47(3), 412 (1983)

[14] T. N.Rescigno, and C. W.McCurdy, Numerical grid methods for quantum-mechanical scattering problems, Phys. Rev. A 62(3), 032706 (2000)

[15] X.Guan, K.Bartschat, and B. I.Schneider, Dynamics of two-photon double ionization of helium in short intense xuv laser pulses, Phys. Rev. A 77(4), 043421 (2008)

[16] X.Guan, K.Bartschat, and B. I.Schneider , Breakup of the aligned H₂ molecule by xuv laser pulses: A time-dependent treatment in prolate spheroidal coordinates, Phys. Rev. A 83(4), 043403 (2011)

[17] B. I.Schneider, L. A.Collins, and S. X.Hu, Parallel solver for the time-dependent linear and nonlinear Schrödinger equation, Phys. Rev. E 73(3), 036708 (2006)

[18] A. D.Bandrauk, S.Chelkowski, D. J.Diestler, J.Manz, and K. J.Yuan, Quantum simulation of high-order harmonic spectra of the hydrogen atom, Phys. Rev. A 79(2), 023403 (2009)

[19] A. A.Silaev, M. Yu.Ryabikin, and N. V.Vedenskii, Strong-field phenomena caused by ultrashort laser pulses: Effective one- and two-dimensional quantum-mechanical descriptions, Phys. Rev. A 82(3), 033416 (2010)

[20] K.Burnett, V. C.Reed, J.Cooper, and P. L.Knight, Calculation of the background emitted during high-harmonic generation, Phys. Rev. A 45(5), 3347 (1992)

[21] S. F.Zhao, X. X.Zhou, P. C.Li, and Z. J.Chen, Isolated short attosecond pulse produced by using an intense few-cycle shaped laser and an ultraviolet attosecond pulse, Phys. Rev. A 78(6), 063404 (2008)

[22] Y.Hong, P. X.Lu, P. F.Lan, Z. Y.Yang, Y. H.Li, and Q.Liao, Broadband xuv supercontinuum generation via controlling quantum paths by a low-frequency field, Phys. Rev. A 77(3), 033410 (2008)

[23] Z.Zhai, R. F.Yu, X. S.Liu, and Y. J.Yang, Enhancement of high-order harmonic emission and intense sub-50-as pulse generation, Phys. Rev. A 78(4), 041402 (2008) (R)

[24] G.Chen, S. L.Liang, and Y. J.Yang, Generation of isolated sub-50-as pulses by quantum path control in the multicycle regime, Phys. Rev. A 82(4), 043401 (2010)

[25] E. J.Takahashi,P.Lan, O. D.Mücke, Y.Nabekawa, and K.Midorikawa, Infrared two-color multicycle laser field synthesis for generating an intense attosecond pulse, Phys. Rev. Lett. 104(23), 233901 (2007)

[26] A.Pukhov, S.Gordienko, and T.Baeva, Temporal structure of attosecond pulses from intense laser-atom interactions, Phys. Rev. Lett. 91(17), 173002 (2003)

RIGHTS & PERMISSIONS

Higher Education Press and Springer-Verlag Berlin Heidelberg