Ptychographic hyperspectral spectromicroscopy with an extreme ultraviolet high harmonic comb

TL;DR

This paper introduces a novel EUV hyperspectral spectromicroscopy technique using ptychographical information multiplexing with a high harmonic EUV source, enabling simultaneous imaging of spectral response and beam characterization without additional hardware.

Contribution

The work extends ptychographical information multiplexing to EUV wavelengths, achieving high-resolution, multicolor imaging and in situ beam characterization with a simple, hardware-efficient setup.

Findings

Simultaneous spectral and spatial imaging in the EUV range.

High spatial resolution with multicolor EUV imaging.

Efficient beam characterization without additional hardware.

Abstract

We demonstrate a new scheme of spectromicroscopy in the extreme ultraviolet (EUV) spectral range, where the spectral response of the sample at different wavelengths is imaged simultaneously. It is enabled by applying ptychographical information multiplexing (PIM) to a tabletop EUV source based on high harmonic generation, where four spectrally narrow harmonics near 30 nm form a spectral comb structure. Extending PIM from previously demonstrated visible wavelengths to the EUV/X-ray wavelengths promises much higher spatial resolution and more powerful spectral contrast mechanism, making PIM an attractive spectromicroscopy method in both the microscopy and the spectroscopy aspects. Besides the sample, the multicolor EUV beam is also imaged in situ, making our method a powerful beam characterization technique. No hardware is used to separate or narrow down the wavelengths, leading to efficient use of the EUV radiation.