Excitation with effective subcycle laser pulses.

Area of Science:

• Quantum optics and atomic physics
• Ultrafast laser science

Background:

• Multiphoton excitation is a fundamental process in atomic physics.
• Controlling excitation pathways requires precise manipulation of laser pulse properties.

Purpose of the Study:

• To demonstrate multiphoton excitation of the xenon 5g state using temporally shaped laser pulses.
• To investigate excitation dynamics with subcycle laser pulse durations.
• To explore the role of polarization in selective atomic excitation.

Main Methods:

• Utilized polarization-gated laser pulses with specific temporal shaping.
• Employed circularly polarized pulse edges and a linearly polarized central 'gate'.
• Applied electron imaging spectroscopy to probe excited states.

Main Results:

• Achieved selective multiphoton excitation of xenon to the 5g state.
• Demonstrated that only the linearly polarized component of the pulse drives the excitation.
• Showcased excitation with an effective pulse duration as short as 2.3 femtoseconds.

Conclusions:

• Temporally shaped polarization pulses enable subcycle control over multiphoton excitation.
• This method provides a pathway to study ultrafast atomic dynamics.
• The findings highlight the importance of polarization selection rules in atomic transitions.