Soft X-ray attosecond transient absorption spectroscopy at 400eV

Speaker:  Jiro Itatani, University of Tokyo

Program Description:
I will present our recent results of isolated attosecond pulse generation in the soft x-ray region using a BiBO-based optical parametric chirped pulse amplifier [1] and its application to soft-x-ray TAS experiments on strong field-driven NO and N2O molecules probed at the nitrogen K edge (~400 eV) [2, 3]. In the NO experiment, field-driven electronic, vibrational, and rotational dynamics were clearly traced in a single TAS setup.  In the N2O experiment, half-cycle oscillations of the drive IR field were observed, which were attributed to tunnel ionization of inner-shell excited neutral molecules.

References

[1]     N. Ishii, K. Kaneshima, T. Kanai, S. Watanabe, and J. Itatani, "Generation of sub-two-cycle millijoule infrared pulses in an optical parametric chirped-pulse amplifier and their application to soft x-ray absorption spectroscopy with high-flux high harmonics," J. Opt. 20, 014003 (2018).

[2]     N. Saito, H. Sannohe, N. Ishii, T. Kanai, N. Kosugi, Y. Wu, A. Chew, S. Han, Z. Chang, and J. Itatani, "Real-time observation of electronic, vibrational, and rotational dynamics in nitric oxide with attosecond soft x-ray pulses at 400 eV," Optica 6, 1542 (2019).

[3]     N. Saito, N. Douguet, H. Sannohe, N. Ishii, T. Kanai, Y. Wu, A. Chew, S. Han, B. I. Schneider, J. Olsen, L. Argenti, Z. Chang, and J. Itatani, "Attosecond electronic dynamics of core-excited states of N2O in the soft x-ray region," Phys. Rev. Res. 3, 043222 (2021).