Temporal characterization of individual harmonics of an attosecond pulse train by THz streaking

TL;DR

This paper introduces a method using THz streaking to directly measure the temporal characteristics of individual harmonics in an attosecond pulse train, revealing how pulse duration and chirp vary with harmonic order.

Contribution

It presents a novel THz streaking technique for direct, scanless measurement of individual harmonic pulse durations and chirp in attosecond pulse trains.

Findings

Pulse durations decrease with increasing harmonic order.

Linear chirp reduces as harmonic order increases.

Method enables direct retrieval without temporal scanning.

Abstract

We report on the global temporal pulse characteristics of individual harmonics in an attosecond pulse train by means of photo-electron streaking in a strong low-frequency transient. The scheme allows direct retrieval of pulse durations and first order chirp of individual harmonics without the need of temporal scanning. The measurements were performed using an intense THz field generated by tilted phase front technique in LiNbO_3 . Pulse properties for harmonics of order 23, 25 and 27 show that the individual pulse durations and linear chirp are decreasing by the harmonic order.