Generation of a Spherical Focal Spot in a 4Pi Focusing System through Reversing the Radiation of Infinite Biconical Antenna
Document Type
Article
Publication Date
9-2015
Publication Source
Optics Communications
Abstract
A method of generating spherical focal spot is demonstrated through reversely propagating and tightly focusing the electric field at the pupil plane radiated from an infinite biconical antenna centered at the foci of two confocal high numerical aperture aplanatic objective lenses. The required incident field distribution at the pupil plane is found by solving the inverse problem of radiation from an infinite biconical antenna using the Richards–Wolf vectorial diffraction theory. Numerical simulations show that a focal spot of excellent spherical symmetry along with extremely low sidelobe (~4.72% of the peak) and diffraction limited spot size of 0.432λ can be obtained in a 4Pi focusing system.
It is also shown that the generated focal spot can be shifted along the optical axis while still maintaining its spherical shape and diffraction limited size through introducing a phase difference between the pupil illumination fields of the two objective lenses used in the 4Pi focusing system.
Inclusive pages
217–221
ISBN/ISSN
0030-4018
Copyright
Copyright © 2015, Elsevier
Publisher
Elsevier
Volume
350
Peer Reviewed
yes
eCommons Citation
Yu, Yanzhong and Zhan, Qiwen, "Generation of a Spherical Focal Spot in a 4Pi Focusing System through Reversing the Radiation of Infinite Biconical Antenna" (2015). Electro-Optics and Photonics Faculty Publications. 48.
https://ecommons.udayton.edu/eop_fac_pub/48
Comments
Permission documentation is on file.