Post on 27-Jul-2020
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Plasmonic Waveguide Analysis
User Presentations, - RF, Microwave and Plasma
Sergei Yushanov, Jeffrey Crompton, and Kyle Koppenhoefer
8 October 2015
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Objective
• Provide comparison of numerical and analytic solutions for a plasmonic waveguide
• Extend solution method to surface plasmoncoplanar waveguide
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What is a Surface Plasmon?
• Electromagnetic excitations that propagate at the interface between a dielectric and a conductor
• Evanescently confined in the perpendicular direction to the propagation
• Arise by coupling of the electromagnetic field to oscillations of the conductor’s electron plasma
• Everyday example – stained glass
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guided wave
substrate
film
cladding
x
y
z
plasmonic waveguide
x
y
aa−
cε
sεfε
Dielectric-metal dielectric (DMD) and metal-dielectric-metal (MDM)
Only TM plasmonic modes will be considered
Plasmonic Waveguide Geometry
Two-dimensional model
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Physics
( ) 01
0
20 =
−−×∇×∇ EEωεσε
µjk r
r
Maxwell’s Wave Equation:
Electromagnetic Waves, Frequency Domain (emw) physics interface is used to solve governing equation
Electric field components are solved for “In-plane vector”.
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cε
fε
sε
Num
eric
Por
t
Num
eric
Por
ta2x
y
Physics – Boundary Conditions
Wave excitation = “On”Launches wave
Wave excitation = “Off”Maintains mode of
launched wave in x -dir
Boundary Conditions IrrelevantFar from interface
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Material Properties – Dielectric Constants
cε
fε
sεN
umer
ic P
ort
Num
eric
Por
ta2x
y
Configuration Substrate, Film, Cladding,
DMD 1.7 -4 3.5
MDM -1.6 2.2 -4
sε fε cε
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Solution Method
• Two boundary mode analysis steps– Eigenvalue solution for the fields and propagation
constants at the boundaries
• Frequency domain step
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Comparison with Analytic Solution
cε
fε
sε
a2
x
y
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Comparison with Analytic Solution
cε
fε
sε
a2
x
y
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Electric field distribution - DMD waveguide
THzf 54.9= THzf 8.66=
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Coplanar Waveguide Problem
nmgw 50==nmh 100=
2SiO
Silver
Drude model dielectric function
nm15000 =λ
8.32=SiOε
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Electric Field – Longitudinal Component
Even Modes
Surface PlasmonCoplanar Waveguide
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Electric Field – Longitudinal Component
Odd Modes
Surface PlasmonCoplanar Waveguide
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Summary
• Plasmonic layered waveguide (DMD and MDM) analyzed
• Comparison with analytical solution verifies methodology
• Technique extended to surface plasmon coplanar waveguide
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