RT Journal Article T1 Experimental validation of designs for permeable diffractive lenses based on photon sieves for the sensing of running fluids A1 Pastor Villarrubia, Verónica A1 Soria García, Ángela A1 Andres Porras, Joaquin A1 Del Hoyo Muñoz, Jesús A1 Elshorbagy, Mahmoud H. A1 Sánchez Brea, Luis Miguel A1 Alda Serrano, Javier AB This study reports the experimental validation of several designs of photon sieves with focusing capabilities. These permeable optical elements were implemented with a spatial light modulator working in pure-amplitude mode. The focal region was scanned using a traveling stage, holding a camera. Using this experimental setup, we characterized the focal region of the photon sieves and determined some parameters of interest, such as the depth of focus and the transverse extent of the focal region. These parameters and their evolution were measured and analyzed to compare the optical performance of different designs. Moreover, the permeability of the mask was also evaluated and is included in the discussion. When the photon sieve is intended to be used as an optical element for the monitoring of running fluids, one of the designs studied, labeled the Ring-by-Ring method, behaves in a quite balanced manner and thus has become the preferred choice. Through simulations for a refractometric sensor, we obtained the Figure of Merit of the Ring-by-Ring mask, which reached a maximum value of 7860 RIU−1, which is competitive with plasmonic sensing devices PB MDPI YR 2025 FD 2025-05-14 LK https://hdl.handle.net/20.500.14352/136600 UL https://hdl.handle.net/20.500.14352/136600 LA eng NO Pastor-Villarrubia, V., Soria-Garcia, A., Andres-Porras, J., Del Hoyo, J., Elshorbagy, M.H., Sanchez-Brea, L.M., Alda, J., 2025. Experimental Validation of Designs for Permeable Diffractive Lenses Based on Photon Sieves for the Sensing of Running Fluids. Photonics 12, 486. https://doi.org/10.3390/photonics12050486 NO © 2025 by the authors. NO European Commision NO Ministerio de Ciencia e Innovacion (España) NO Agencia Estatal de Investigación NO Universidad Complutense de Madrid NO Banco Santander DS Docta Complutense RD 8 may 2026