2026-10-11T11:02:21Z https://api.figshare.com/v2/oai

oai:figshare.com:article/34021653 2026-09-30T05:33:47Z category_37464 portal_1023 item_type_12 month_year_09_2026

Precision measurement of high-aspect-ratio micro-hole aperture based on far-field diffraction FWHM analysis of Gaussian beams Lu Liao (14113800) Wei Gao (2085) Optical Sensors, Measurements, and Metrology Gaussian beam far-field diffraction FWHM high-aspect-ratio micro-hole aperture measurement optical metrology To address the challenge of accurately measuring the aperture of high-aspect-ratio thick pinholes used in inertial confinement fusion (ICF) diagnostics, a non-contact aperture inversion method based on the far-field diffraction full width at half maximum (FWHM) of a Gaussian beam is proposed. Addressing the limitations of the traditional thin-aperture Airy model—which neglects waveguide confinement, edge truncation, and inner-wall scattering—a hybrid light-field reconstruction (HLFR) model is established and propagated using angular spectrum theory. Comparative analysis shows that the main spot FWHM exhibits superior robustness against wavefront non-uniformity and non-ideal scattering compared to conventional Airy pattern features. By applying a dual-parameter adaptive correction combining aperture and hole length across 25 simulated samples, the relative FWHM inversion error is significantly reduced from 8.72% to within 1.20%. Experimental validation on four physical thick pinholes demonstrates strong consistency across propagation distances, with a blind-test deviation of approximately 0.5%. This work provides a highly accurate and robust non-contact technical approach for the geometric inspection of large aspect ratio microstructures. 2026-09-30T05:33:47Z Text Preprint 10.1364/opticaopen.34021653.v1 https://figshare.com/articles/preprint/Precision_measurement_of_high-aspect-ratio_micro-hole_aperture_based_on_far-field_diffraction_FWHM_analysis_of_Gaussian_beams/34021653 Optica Publishing Group Non-Exclusive License