Attosecond Lighthouses

TL;DR

This paper introduces the attosecond lighthouse, a novel method to generate angularly separated, isolated attosecond pulses using spatio-temporal coupling of electromagnetic fields, advancing ultrafast light source technology and metrology.

Contribution

It demonstrates how spatio-temporal coupling can be exploited to produce a new class of attosecond light sources with potential applications in ultrafast science and metrology.

Findings

Generation of angularly separated attosecond pulses

Potential for improved pump-probe experiments

Access to laser field phase fluctuations at focus

Abstract

Coherent light beams composed of ultrashort pulses are now increasingly used in different fields of Science, from time-resolved spectroscopy to plasma physics. Under the effect of even simple optical components, the spatial properties of these beams can vary over the duration of the light pulse. In this letter, we show how such spatio-temporally coupled electromagnetic fields can be exploited to produce an attosecond lighthouse, i.e. a source emitting a collection of isolated attosecond pulses, propagating in angularly well-separated light beams. This very general effect not only opens the way to a new generation of attosecond light sources, particularly suitable for pump-probe experiments, but also provides a powerful new tool for ultrafast metrology, for instance giving direct access to fluctuations in the phase of the laser field oscillations with respect to the pulse envelop, right at the focus of even the most intense ultrashort laser beams.