Spectrally resolved single-shot wavefront sensing of broadband high-harmonic sources

TL;DR

This paper presents a novel spectrally resolved wavefront sensor capable of measuring all spectral components of broadband high-harmonic beams simultaneously in a single shot, enabling detailed characterization of ultrafast EUV sources.

Contribution

The authors introduce a new wavefront sensor that captures wavefronts and spectra of multiple harmonics simultaneously using transmission gratings, improving broadband EUV beam analysis.

Findings

Measured wavefronts of 9 harmonics between 25-49 nm in a single shot.

Achieved wavefront measurement precision up to lambda/32.

Demonstrated capability to detect spatiotemporal structures like pulse front tilt.

Abstract

Wavefront sensors are an important tool to characterize coherent beams of extreme ultraviolet radiation. However, conventional Hartmann-type sensors do not allow for independent wavefront characterization of different spectral components that may be present in a beam, which limits their applicability for intrinsically broadband high-harmonic generation (HHG) sources. Here we introduce a wavefront sensor that measures the wavefronts of all the harmonics in a HHG beam in a single camera exposure. By replacing the mask apertures with transmission gratings at different orientations, we simultaneously detect harmonic wavefronts and spectra, and obtain sensitivity to spatiotemporal structure such as pulse front tilt as well. We demonstrate the capabilities of the sensor through a parallel measurement of the wavefronts of 9 harmonics in a wavelength range between 25 and 49 nm, with up to lambda/32 precision.