Ultrafast processes in matter can be captured and even controlled by using sequences of few-cycle optical pulses, which need to be well characterized, both in amplitude and phase. The same degree of control has not yet been achieved for few-cycle extreme ultraviolet pulses generated by high-order harmonic generation (HHG) in gases, with duration in the attosecond range. Here, we show that by varying the spectral phase and carrier-envelope phase (CEP) of a high-repetition rate laser, using dispersion in glass, we achieve a high degree of control of the relative phase and CEP between consecutive attosecond pulses. The experimental results are supported by a detailed theoretical analysis based upon the semi-classical three-step model for HHG.
Publication Source (Journal or Book title)
Journal of Physics B: Atomic, Molecular and Optical Physics
Guo, C., Harth, A., Carlström, S., Cheng, Y., Mikaelsson, S., Marsell, E., Heyl, C., Miranda, M., Gisselbrecht, M., Gaarde, M., Schafer, K., Mikkelsen, A., Mauritsson, J., Arnold, C., & L'Huillier, A. (2018). Phase control of attosecond pulses in a train. Journal of Physics B: Atomic, Molecular and Optical Physics, 51 (3) https://doi.org/10.1088/1361-6455/aa9953