Abstract

Nano-antennas are used in optical data storage, near-field imaging, photovoltaics, sensing, and spectroscopy applications. In many cases, the antennas work with linear polarization, but some applications require circularly polarized (CP) light such as field-enhanced circular dichroism spectroscopy. Circular dichroism spectroscopy is a technique used to study organic molecules and is widely used in biology and medicine. In this article, we analyze a star-gap nano-antenna array. The antenna combines concentric circular gratings and a symmetric gap to provide a maximum electric field enhancement factor of around 48 at 780 nm with the average electric field enhancement factor of about 34.75. Due to its geometry, the antenna can work for both linearly polarized and CP light, having similar electric field enhancement factors. Due to its symmetry and capacity to work with different polarizations, the antenna can find applications in sensing and spectroscopy. As an example of application, we have characterized the antenna for surface enhanced Raman scattering (SERS) and obtained a SERS factor of $ 4.18 \times {10^6} $ for the $ 880\,\,{\rm{cm}^{ - 1}} $ Raman line of ethanol.

© 2019 Optical Society of America

Full Article  |  PDF Article
OSA Recommended Articles
Integration of bow-tie plasmonic nano-antennas on tapered fibers

Abdul Khaleque, Evgeny G. Mironov, Jonas H. Osório, Ziyuan Li, Cristiano M. B. Cordeiro, Liming Liu, Marcos A. R. Franco, Jong-Leng Liow, and Haroldo T. Hattori
Opt. Express 25(8) 8986-8996 (2017)

Arrays of recycled power TM polarized nano-antennas

Haroldo T. Hattori and Ziyuan Li
Opt. Express 21(14) 16273-16281 (2013)

Mass-producible and efficient optical antennas with CMOS-fabricated nanometer-scale gap

Tae Joon Seok, Arash Jamshidi, Michael Eggleston, and Ming C. Wu
Opt. Express 21(14) 16561-16569 (2013)

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 (8)

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

Tables (2)

You do not have subscription access to this journal. Article tables 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 (5)

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