This invention describes a planar reflective optical platform for extreme ultraviolet wavelengths based on guided-mode resonators in thin-film dielectric waveguides. The invention enables reflective wavefront control, focusing, and aberration correction through nonlocal metasurface physics. This eliminates the need for multilayer Bragg reflectors. Background: Extreme ultraviolet (EUV) optical systems often face fundamental challenges arising from material optical properties in this regime because nearly all solid materials exhibit refractive indices slightly below unity with significant absorption at EUV wavelengths. Current systems use Bragg reflector mirrors to achieve 70% reflectivity, but suffer from angular bandwidth limitations, fabrication complexity for focusing elements, and multi-element requirements to compensate for aberrations. There is a persistent need across the field for planar reflective EUV optical elements capable of achieving high numerical imaging and wavefront control without the need for curved multilayer mirror systems due to their complexity, costs, and scalability limitations. Applications:
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