Phase-dependent effects of a few-cycle laser pulse

Area of Science:

• Atomic, Molecular, and Optical Physics
• Quantum Optics
• Ultrafast Laser Science

Background:

• Above-threshold ionization (ATI) is a fundamental process in strong-field physics.
• Few-cycle laser pulses offer unique interactions due to their short duration and phase characteristics.
• Measuring the carrier-envelope phase (CEP) difference is crucial for controlling and understanding ultrafast laser-matter interactions.

Purpose of the Study:

• To apply the Keldysh theory to analyze carrier-envelope phase dependent phenomena in few-cycle above-threshold ionization.
• To investigate a novel correlation technique for measuring the left-right asymmetry in few-cycle ATI.
• To establish a method for determining the duration of few-cycle laser pulses with uncontrolled CEP.

Main Methods:

• Theoretical application of the Keldysh theory to few-cycle laser pulse interactions.
• Experimental measurement of carrier-envelope phase dependent left-right asymmetry in few-cycle ATI using a correlation technique.
• Analysis of spectral features associated with the measured asymmetry.

Main Results:

• Demonstrated the carrier-envelope phase dependence of left-right asymmetry in few-cycle ATI.
• Successfully employed a correlation technique to measure this asymmetry.
• Established a theoretical framework linking spectral asymmetry to pulse duration for uncontrolled CEP pulses.

Conclusions:

• The Keldysh theory provides a valid framework for understanding CEP effects in few-cycle ATI.
• The developed correlation technique is effective for measuring CEP-dependent asymmetries.
• A novel method is presented to determine few-cycle pulse durations when CEP is not controlled.