Abstract
Surface plasmon polaritons (SPPs) are collective electron oscillations,
confined at metal-dielectric interfaces. Coupling incident photons to SPPs
may lead to spectrally broad field enhancement and confinement below the
diffraction limit [1]. This phenomenon facilitates various applications,
including highly sensitive refractive index sensing [2], and plasmonic dipole
mirrors for cold atoms [3]. Key to a successful application is a strong
photon-to-SPP coupling. To this end, prism-based coupling is classically
used, but this method contradicts compact device applications. An alternative
realization is given by the use of a metallic diffraction grating, where the
diffracted light couples to the SPP.
Here, we propose metallic periodic transmission gratings, processed onto a
glass substrate, with various periods and fill factors. The gratings are
milled in a plain gold layer with a focused ion beam (FIB) microscope, using
gallium and a neutralizing electron beam. We investigate the SPP coupling
strength with respect to varying top layers and under collimated,
oblique-angled excitation, with respect to the effect of finite gratings as
opposed to perfect periodicity. We characterize the proposed plasmonic
transmission gratings via near-field optical scanning microscopy (NSOM) and
goniometric far field measurements. We support the evidence of our analyses
with numerical calculations, carried out via rigorous coupled wave analysis
(RCWA) and finite-difference in time-domain (FDTD) Simulations.
[1] W. L. Barnes, A. Dereux, T. W. Ebbesen, Nature 424, 824–830 (2003)
[2] X. D. Hoa, A. G. Kirk, M. Tabrizian, Biosensors and Bioelectronics, 23,
2, 151-160 (2007)
[3] T. Kawalec, et al., Opt. Lett. 39, 2932 (2014)
confined at metal-dielectric interfaces. Coupling incident photons to SPPs
may lead to spectrally broad field enhancement and confinement below the
diffraction limit [1]. This phenomenon facilitates various applications,
including highly sensitive refractive index sensing [2], and plasmonic dipole
mirrors for cold atoms [3]. Key to a successful application is a strong
photon-to-SPP coupling. To this end, prism-based coupling is classically
used, but this method contradicts compact device applications. An alternative
realization is given by the use of a metallic diffraction grating, where the
diffracted light couples to the SPP.
Here, we propose metallic periodic transmission gratings, processed onto a
glass substrate, with various periods and fill factors. The gratings are
milled in a plain gold layer with a focused ion beam (FIB) microscope, using
gallium and a neutralizing electron beam. We investigate the SPP coupling
strength with respect to varying top layers and under collimated,
oblique-angled excitation, with respect to the effect of finite gratings as
opposed to perfect periodicity. We characterize the proposed plasmonic
transmission gratings via near-field optical scanning microscopy (NSOM) and
goniometric far field measurements. We support the evidence of our analyses
with numerical calculations, carried out via rigorous coupled wave analysis
(RCWA) and finite-difference in time-domain (FDTD) Simulations.
[1] W. L. Barnes, A. Dereux, T. W. Ebbesen, Nature 424, 824–830 (2003)
[2] X. D. Hoa, A. G. Kirk, M. Tabrizian, Biosensors and Bioelectronics, 23,
2, 151-160 (2007)
[3] T. Kawalec, et al., Opt. Lett. 39, 2932 (2014)
| Originalsprog | Engelsk |
|---|---|
| Publikationsdato | 2016 |
| Status | Udgivet - 2016 |
| Begivenhed | E-MRS Fall Meeting - Warsaw University of Technology, Warsaw, Polen Varighed: 19. sep. 2016 → 22. sep. 2016 http://www.european-mrs.com/meetings/2016-fall/2016-fall-symposia-program |
Konference
| Konference | E-MRS Fall Meeting |
|---|---|
| Lokation | Warsaw University of Technology |
| Land/Område | Polen |
| By | Warsaw |
| Periode | 19/09/2016 → 22/09/2016 |
| Internetadresse |