Abstract
Full text: Reported in this paper is a new phenomenon that the focal spot of a high numerical-aperture objective in free space can split into two spots if a ring beam is used for illumination. Diffraction by a high numerical-aperture objective results in a depolarization nature that the diffracted field in the focal region includes a component with the same polarization as the incident beam but also orthogonal and longitudinal components. The use of a ring beam enhances the relative contribution from the longitudinal component. As a result, a single focal spot splits into two spots along the incident polarization direction. It is revealed theoretically that for an objective of given numerical aperture there is a threshold of the central obstruction size of a ring beam for the appearance of a two-peak focus.
Chon, J W.M.;
Gan, X;
Gu, M
[1]
- Swinburne University of Technology, (Australia). School of Biophysical Sciences and Electrical Engineering, Centre for Micro-Photonics
Citation Formats
Chon, J W.M., Gan, X, and Gu, M.
Splitting of the focal spot of a high numerical-aperture objective lens in free space.
Australia: N. p.,
2002.
Web.
Chon, J W.M., Gan, X, & Gu, M.
Splitting of the focal spot of a high numerical-aperture objective lens in free space.
Australia.
Chon, J W.M., Gan, X, and Gu, M.
2002.
"Splitting of the focal spot of a high numerical-aperture objective lens in free space."
Australia.
@misc{etde_20619807,
title = {Splitting of the focal spot of a high numerical-aperture objective lens in free space}
author = {Chon, J W.M., Gan, X, and Gu, M}
abstractNote = {Full text: Reported in this paper is a new phenomenon that the focal spot of a high numerical-aperture objective in free space can split into two spots if a ring beam is used for illumination. Diffraction by a high numerical-aperture objective results in a depolarization nature that the diffracted field in the focal region includes a component with the same polarization as the incident beam but also orthogonal and longitudinal components. The use of a ring beam enhances the relative contribution from the longitudinal component. As a result, a single focal spot splits into two spots along the incident polarization direction. It is revealed theoretically that for an objective of given numerical aperture there is a threshold of the central obstruction size of a ring beam for the appearance of a two-peak focus.}
place = {Australia}
year = {2002}
month = {Jul}
}
title = {Splitting of the focal spot of a high numerical-aperture objective lens in free space}
author = {Chon, J W.M., Gan, X, and Gu, M}
abstractNote = {Full text: Reported in this paper is a new phenomenon that the focal spot of a high numerical-aperture objective in free space can split into two spots if a ring beam is used for illumination. Diffraction by a high numerical-aperture objective results in a depolarization nature that the diffracted field in the focal region includes a component with the same polarization as the incident beam but also orthogonal and longitudinal components. The use of a ring beam enhances the relative contribution from the longitudinal component. As a result, a single focal spot splits into two spots along the incident polarization direction. It is revealed theoretically that for an objective of given numerical aperture there is a threshold of the central obstruction size of a ring beam for the appearance of a two-peak focus.}
place = {Australia}
year = {2002}
month = {Jul}
}