title: Measurement of the three-dimensional intensity distribution in the neighborhood of a paraxial focus.
abstract: We describe a technique for measuring the three-dimensional(3D) intensity distribution of a paraxial focus, based on scanning a CCD image sensor along the optical axis and on subsequently analyzing the data. We demonstrate the possibility of measuring high-resolution 3D intensity maps of the focal field, down to intensities of more than 5 orders of magnitude below that in the focal point, and show the excellent agreement with scalar diffraction theory. Further applications of the technique are indicated.
authors.forename: G P
authors.initials: GP
authors.lastname: Karman
authors.forename: A
authors.initials: A
authors.lastname: van Duijl
authors.forename: M W
authors.initials: MW
authors.lastname: Beijersbergen
authors.forename: J P
authors.initials: JP
authors.lastname: Woerdman