All-optical frequency resolved optical gating for isolated attosecond pulse reconstruction

TL;DR

This paper introduces an all-optical method for accurately characterizing isolated attosecond pulses generated from high-order harmonics, using phase perturbation and frequency resolved optical gating for precise pulse reconstruction.

Contribution

It presents a novel in situ technique that reconstructs attosecond pulses without relying on the central momentum approximation, enhancing measurement reliability.

Findings

Successful reconstruction of isolated attosecond pulses using the proposed method.

The method avoids assumptions inherent in attosecond streaking techniques.

Provides a simple, reliable metrology for attosecond pulse characterization.

Abstract

We demonstrate an all-optical approach for precise characterization of attosecond extreme ultraviolet pulses. Isolated attosecond pulse is produced from high order harmonics using intense driving pulse with proper gating technique. When a weak field is synchronized with the driver, it perturbs the harmonics generation process via altering the accumulated phase of the electron trajectories. The perturbed harmonic spectrum can be formulated as a convolution of the unperturbed dipole and a phase gate, implying the validity of complete reconstruction of isolated attosecond pulses using conventional frequency resolved optical gating method. This in situ measurement avoids the central momentum approximation assumed in the widely used attosecond streaking measurement, providing a simple and reliable metrology for isolated attosecond pulse.