Surface plasmon based enhanced transmission of electromagnetic waves
Author
Bıyıklı, Süheyla Sena Akarca
Advisor
Özbay, Ekmel
Date
2004Publisher
Bilkent University
Language
English
Type
ThesisItem Usage Stats
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Abstract
Grating-coupling phenomena between surface plasmons and electromagnetic
waves are studied in the microwave spectrum using metallic gratings.
Transmission and reflection measurements were carried out to observe the
transmitted and reflected radiation around the surface plasmon resonance
frequencies. Grating structures with subwavelength apertures were designed for
transmission experiments. Measurements were done in the microwave spectrum of
10−37.5 GHz, corresponding to a wavelength region of 8−30 mm. The Al samples
had a grating periodicity of 16 mm. A 2 mm-wide subwavelength slit was opened
for transmission samples. Samples with one/double-sided gratings displayed
remarkably enhanced transmission and directivity with respect to the reference
sample without gratings. The experimental results agreed well with theoretical simulations. ~50% transmission at 20.7 mm, ~25-fold enhancement, and ±4°
angular divergence was achieved with a ~λ/10 aperture. Reflection measurements
of one-sided grating sample resulted in clear observation of surface plasmon
coupling phenomena. Reflectivity peaks were measured around theoretically
calculated resonance frequencies.
Keywords
surface plasmondirectivity
reflection
transmission
microwave radiation
subwavelength aperture
1-D grating structures
plasmon coupling
extraordinary transmission