title: Amplitude and phase microscopy for sizing of spherical particles.
abstract: We describe a numerical vector diffraction model based on Mie theory that describes the imaging of spherical particles by bright-field, confocal, and interferometric microscopes. The model correctly scales the amplitude-scattered field relative to the incident field so that the forward-scattered and incident light can be interfered to correctly model imaging with copolarization transmission microscopes for the first time to our knowledge. The model is used to demonstrate that amplitude and phase imaging with an interferometric microscope allows subwavelength particle sizing. Furthermore, we show that the phase channel allows much smaller particles to be sized than amplitude-only measurements. The model is validated by experimental measurements.
authors.affiliation: University of Nottingham, School of Electrical and Electronic Engineering, University Park, Nottingham NG7 2RD, United Kingdom. nicholas.sawyer@nottingham.ac.uk
authors.forename: Nicolas B E
authors.initials: NB
authors.lastname: Sawyer
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Morgan
authors.forename: Michael G
authors.initials: MG
authors.lastname: Somekh
authors.forename: Chung W
authors.initials: CW
authors.lastname: See
authors.forename: Eugene
authors.initials: E
authors.lastname: Astrakharchik-Farrimond
authors.forename: Boris Y
authors.initials: BY
authors.lastname: Shekunov