High-NA aberration retrieval with the extended Nijboer-Zernike vector diffraction theory

Abstract

The reconstruction of the exit pupil function of an optical system can basically be carried out by collecting intensity data in the focal region from a certain number of defocused image planes. In this paper we present the first results of such a reconstruction operation for optical systems with a high numerical aperture using a point source in the object plane. The main feature of our approach is the use of the extended Nijboer-Zernike diffraction analysis that has been modified to incorporate vector diffraction effects. The quality of the optical system is expressed by means of a set of complex Zernike coefficients that describe the phase and transmission variation in the exit pupil of the imaging system. The ’vector’ method will be compared to the more common scalar diffraction analysis. We also analyse the practical limits of the vector retrieval process regarding the maximum allowed aberration and the noise of the intensity data. The sensitivity of the method with respect to parameter settings (state of polarisation and value of numerical aperture) is also examined.

© The Authors. All rights reserved. [DOI: 10.2971/jeos.2006.06004]