Silva López, ManuelRico García, José MaríaAlda Serrano, Javier2023-06-202023-06-202012-10-08Optica Publishing Group. https://opg.optica.org/oe/viewmedia.cfm?uri=oe-20-21-23875&html=true. Accedido 8 de julio de 2024.1094-408710.1364/OE.20.023875https://hdl.handle.net/20.500.14352/45117En acceso abierto en la web del editor (comprobado en julio 2016).An experimental setup to measure the three-dimensional phase-intensity distribution of an infrared laser beam in the focal region has been presented. It is based on the knife-edge method to perform a tomographic reconstruction and on a transport of intensity equation-based numerical method to obtain the propagating wavefront. This experimental approach allows us to characterize a focalized laser beam when the use of image or interferometer arrangements is not possible. Thus, we have recovered intensity and phase of an aberrated beam dominated by astigmatism. The phase evolution is fully consistent with that of the beam intensity along the optical axis. Moreover, this method is based on an expansion on both the irradiance and the phase information in a series of Zernike polynomials. We have described guidelines to choose a proper set of these polynomials depending on the experimental conditions and showed that, by abiding these criteria, numerical errors can be reduced.engjournal articlehttp://dx.doi.org/10.1364/OE.20.023875https://www.osapublishing.org/oe/abstract.cfm?uri=oe-20-21-23875http://cisne.sim.ucm.es/record=b3528557~S6*spirestricted access535.374537.8LasersLaser opticsLaser beam characterizationTomographic image processingPhase retrievalWafe-front sensingOptical antennasElectromagnetismoTécnicas de la imagenÓptica física, óptica cuánticaLáseres2202 Electromagnetismo2209.19 Óptica física2209.10 Láseres