Spatio-temporal interference of photo electron wave packets and time scale of non-adiabatic transition in high-frequency regime

The method of the envelope Hamiltonian [K. Toyota, U. Saalmann, and J. M. Rost, New J. Phys. {\bf 17}, 073005~(2015)] is applied to further study a detachment dynamics of a model negative ion in one-dimension in high-frequency regime. This method is based on the Floquet approach, but the time-dependency of an envelope function is explicitly kept for arbitrary pulse durations. Therefore, it is capable of describing not only a photo absorption/emission but also a non-adiabatic transition which is induced by the time-varying envelope of the pulse. It was shown that the envelope Hamiltonian accurately retrieves the results obtained by the time-dependent Schr\"odinger equation, and underlying physics were well understood by the adiabatic approximation based on the envelope Hamiltonian. In this paper, we further explore two more aspects of the detachment dynamics, which were not done in our previous work. First, we find out features of both a {\it spatial} and {\it temporal} interference of photo electron wave packets in a photo absorption process. We conclude that both the interference mechanisms are universal in ionization dynamics in high-frequency regime. To our knowledge, it is first time that both the interference mechanisms in high-frequency regime are extracted from the first principle. Second, we extract a pulse duration which maximize a yield of the non-adiabatic transition as a function of a pulse duration. It is shown that it becomes maximum when the pulse duration is comparable to a time-scale of an electron

Pulse shaping with birefringent crystals: a tool for quantum metrology

A method for time differentiation based on a Babinet-Soleil-Bravais compensator is introduced. The complex transfer function of the device is measured using polarization spectral interferometry. Time differentiation of both the pulse field and pulse envelope are demonstrated over a spectral width of about 100 THz with a measured overlap with the objective mode greater than 99.8%. This pulse shaping technique is shown to be perfectly suited to time metrology at the quantum limit