Spectral-gap immune characterization of electric fields

TL;DR

The paper introduces SPICE, a novel multi-spectral shearing interferometry technique that accurately characterizes electric fields with wide spectral gaps, overcoming limitations of existing methods for broadband light sources.

Contribution

It presents a new spectral-gap immune method for electric field characterization using multi-spectral shearing interferometry and a reconstruction algorithm that enhances accuracy and precision.

Findings

Successfully reconstructs electric fields with wide spectral gaps.

Overcomes limitations of self-referencing and direct sampling techniques.

Enables new applications for broadband light sources.

Abstract

Synthesised light sources need reliable diagnostics for effective application to sub-femtosecond control and probing. However, commonly employed self-referencing techniques for pulsed-field characterisation fail in the presence of wide spectral gaps, while direct sampling methods are limited to high intensities. Here, we introduce a new approach labelled SPectral-gap Immune Characterisation of Electric Fields (SPICE), which overcomes these barriers by means of multi-spectral shearing interferometry, using an unknown reference and a reconstruction algorithm that makes use of this redundant information to simultaneously reconstruct the reference and test pulse with high precision and accuracy. We envisage that this technique will help foster new applications for broadband sources.