Martínez-Herrero, RosarioCarnicer González, ArturoJuvells Prades, IgnacioSanz, Ángel S.2021-01-252021-01-252020-09-211094-4087https://hdl.handle.net/2445/173366In the analysis of the on-axis intensity for a highly focused optical field, it is highly desirable to deal with effective relations aimed at characterizing the field behavior in a rather simple fashion. Here, a novel and adequate measure for the size of the region where the axial power content mainly concentrates is proposed on the basis of an uncertainty principle. Accordingly, a meaningful relationship is provided for both the spread of the incident beam at the entrance of the highly focused optical system and the size of the region where the on-axis power mainly concentrates.15 p.application/pdfeng(c) Optical Society of America, 2020Distribució de GaussÒpticaGaussian distributionOpticsinfo:eu-repo/semantics/article7062462021-01-25info:eu-repo/semantics/openAccess