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Itatani Group

Professor ITATANI, Jiro
Research Associate KURIHARA, Takayuki
Project Research Associate MIZUNO, Tomoya
Project Research Associate FUKAYA, Ryo

Research Subjects

  • Development of phase-stable intense ultrashort-pulse lasers
  • Generation of soft-X-ray attosecond pulse, attosecond spectroscopy of atoms, molecules, and solids
  • Measurement and control of ultrafast phenomena in strong optical fields
  • Development of ultrafast soft X-ray spectroscopy

We are working on the development of intense ultrashort pulse light sources and their applications in ultrafast spectroscopy on the femtosecond to attosecond time scale. In light source R&D, we focus on the generation of waveform-controlled intense optical pulses from the visible to the mid-infrared spectral range and the generation of short-wavelength ultrashort pulses using the physics of high-order harmonic generation in gases, solids and liquids. In addition, we are developing the building blocks of next-generation light sources to overcome the limitations of current Ti:sapphire laser-based technologies. Based on these novel light sources and techniques, we are developing attosecond soft X-ray spectroscopy and other ultrafast methods to probe field-driven nonlinear processes in atoms, molecules, solids, and liquids. Our waveform-controlled intense light sources and related technologies will enable novel ultrafast spectroscopy covering an extremely broad spectral range from THz to soft x-rays. Our goal is to observe and control the ultrafast dynamics of non-equilibrium states of matter through multiple degrees of freedom.

Schematic of transient absorption spectroscopy of N2O molecule using attosecond soft x-ray pulses, energy levels involved in inner-shell excitation, and the observed transient absorption spectra. The observed ultrafast modulation is due to the tunnel ionization of the molecule in a core-hole state.
(Left) Carrier-envelope phase dependence of the photoelectron spectra observed by rescattering of laser-accelerated photoelectrons. (Right) Comparison of the differential scattering cross section reconstructed from the observed phase-dependent photoelectron spectra. The good agreement indicates that quantitative information can be obtained from the high-energy rescattering phenomena.

Publications and Research Highlights