Paper
20 February 2008 Fast focus field calculations
Author Affiliations +
Abstract
We present a method for fast calculation of the electromagnetic field near the focus of an objective with a high numerical aperture (NA). Instead of direct integration, the vectorial Debye diffraction integral is evaluated with the fast Fourier transform for calculating the electromagnetic field in the entire focal region. We generalize this concept with the chirp z transform for obtaining a flexible sampling grid and an additional gain in computation speed. Under the conditions for the validity of the Debye integral representation, our method yields the amplitude, phase and polarization of the focus field for an arbitrary paraxial input field in the aperture of the objective. Our fast calculation method is particularly useful for engineering the point-spread function or for fast image deconvolution. We present several case studies by calculating the focus fields of high NA oil immersion objectives for various amplitude, polarization and phase distributions of the input field. In addition, the calculation of an extended polychromatic focus field generated by a Bessel beam is presented. This extended focus field is of particular interest for Fourier domain optical coherence tomography because it preserves a lateral resolution of a few micrometers over an axial distance in the millimeter range.
© (2008) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Marcel Leutenegger, Matthias Geissbuehler, Iwan Märki, Rainer A. Leitgeb, and Theo Lasser "Fast focus field calculations", Proc. SPIE 6861, Three-Dimensional and Multidimensional Microscopy: Image Acquisition and Processing XV, 68610R (20 February 2008); https://doi.org/10.1117/12.763188
Lens.org Logo
CITATIONS
Cited by 6 scholarly publications.
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Objectives

Interfaces

Polarization

Bessel beams

Optical coherence tomography

Fourier transforms

Wave propagation

Back to Top