RT Journal Article T1 Intensity-based axial localization at the quantum limit A1 Řeháček, J. A1 Stoklasa, Bohumil A1 Koutný, Dominik A1 Hradil, Zdenek A1 Sánchez Soto, Luis Lorenzo AB We derive fundamental precision bounds for single-point axial localization. For Gaussian beams, this ultimate limit can be achieved with a single intensity scan, provided the camera is placed at one of two optimal transverse detection planes. Hence, for axial localization there is no need of more complicated detection schemes. The theory is verified with an experimental demonstration of axial resolution 3 orders of magnitude below the classical depth of focus. PB The American Physical Society SN 0031-9007 YR 2019 FD 2019-11-07 LK https://hdl.handle.net/20.500.14352/6020 UL https://hdl.handle.net/20.500.14352/6020 LA eng NO © 2019 American Physical Society.We thank Robert W. Boyd for helpful discussions. We acknowledge financial support from the Czech Science Foundation (Grant No. 18-04291S), the Technology Agency of the Czech Republic (Grant No. TE01020229), the Palacky University (Grant No. IGA_PrF_2019_007), and the Spanish MINECO (Grants No. FIS2015-67963-P and No. PGC2018-099183-B-I00). NO Ministerio de Economía y Competitividad (MINECO) NO Czech Science Foundation NO Technology Agency of the Czech Republic NO Palacky University DS Docta Complutense RD 6 abr 2025