title: Catadioptric aberration correction in cathode lens microscopy.
abstract: In this paper I briefly review the use of electrostatic electron mirrors to correct the aberrations of the cathode lens objective lens in low energy electron microscope (LEEM) and photo electron emission microscope (PEEM) instruments. These catadioptric systems, combining electrostatic lens elements with a reflecting mirror, offer a compact solution, allowing simultaneous and independent correction of both spherical and chromatic aberrations. A comparison with catadioptric systems in light optics informs our understanding of the working principles behind aberration correction with electron mirrors, and may point the way to further improvements in the latter. With additional developments in detector technology, 1 nm spatial resolution in LEEM appears to be within reach.
authors.affiliation: IBM T.J. Watson Research Center, PO Box 218, Yorktown Heights, NY 10598, USA; Kamerlingh Onnes Laboratory, Leiden Institute of Physics, Niels Bohrweg 2, 2333 CA Leiden, The Netherlands.
authors.forename: R M
authors.initials: RM
authors.lastname: Tromp
keywords: Low energy electron microscopy aberration correction electron mirror optics