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arXiv · 2604.25485

Submicrometer focusing of isolated attosecond XUV pulses approaching 10$^{16}$ W/cm$^2$

Kotaro Imasaka·Dianhong Dong·Natsuki Kanda·Bing Xue·Satoru Egawa·Takuya Hosobata·Yutaka Yamagata·Yasuo Nabekawa·Eiji J. Takahashi
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Abstract

We demonstrate submicrometer focusing of isolated attosecond pulses (IAPs) in the extreme ultraviolet (XUV) region using a custom ellipsoidal mirror. The obtained focal spot sizes were verified using knife-edge measurements with a sharp silicon edge, confirming reproducible dimensions down to 0.46 $\mu$m $\times$ 0.36 $\mu$m (FWHM), approaching the diffraction limit. Focusing a 1.1-GW tabletop IAP source yields a peak intensity of 3 $\times$ 10$^{15}$ W/cm$^2$, and a realistic pathway toward 10$^{16}$ W/cm$^2$ is obtained by optimizing the beamline throughput. These results establish a practical route toward attosecond nonlinear optics in both gas and solid phases, driven by intense XUV fields.

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BibTeXRIS

Kotaro Imasaka, Dianhong Dong, Natsuki Kanda, Bing Xue, Satoru Egawa, Takuya Hosobata, Yutaka Yamagata, Yasuo Nabekawa, Eiji J. Takahashi. 2026-04-28. Submicrometer focusing of isolated attosecond XUV pulses approaching 10$^{16}$ W/cm$^2$. https://arxiv.org/abs/2604.25485

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