Abstract

Using Richards–Wolf formulas, we show analytically that when strongly focusing a circularly polarized axisymmetric non-vortex field (e.g., a Gaussian beam or zero-order Bessel–Gaussian beam), a spiral energy flow is produced around the sub-wavelength focal spot. This phenomenon can be explained by the conversion of spin angular momentum associated with the circular polarization state into the near-focus orbital angular momentum, with the on-axis angular momentum being strictly zero. It is also shown that a linearly polarized optical vortex with topological charge 2 produces an on-axis near-focus energy backflow whose amplitude (defined by the negative longitudinal component of the Poynting vector) is comparable with that of the incident beam.

© 2019 Optical Society of America

Full Article  |  PDF Article
OSA Recommended Articles
Reverse and toroidal flux of light fields with both phase and polarization higher-order singularities in the sharp focus area

Victor V. Kotlyar, Sergey S. Stafeev, and Alexey A. Kovalev
Opt. Express 27(12) 16689-16702 (2019)

Energy density and energy flux in the focus of an optical vortex: reverse flux of light energy

Victor V. Kotlyar, Alexey A. Kovalev, and Anton G. Nalimov
Opt. Lett. 43(12) 2921-2924 (2018)

Longitudinal field characterization of converging terahertz vortices with linear and circular polarizations

Xinke Wang, Jing Shi, Wenfeng Sun, Shengfei Feng, Peng Han, Jiasheng Ye, and Yan Zhang
Opt. Express 24(7) 7178-7190 (2016)

References

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Figures (5)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Equations (21)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Metrics

You do not have subscription access to this journal. Article level metrics are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription