Kartik Goyal presented his dissertation on the design and optimization of optical Yagi-Uda nantennas for beam steering applications. He discussed the need for optical nantennas in applications such as communication, photovoltaics, and medical imaging. Through his research, he analyzed different nantenna designs, materials, and substrates. His final optimized design was a 9-element circular loop optical Yagi-Uda nantenna made of gold with a gallium arsenide substrate that achieved high directivity for beam steering.

1. Dissertation Presentation on
Design and Optimization of Optical Yagi-Uda
Nantenna for beam steering applications
Presented By-
Kartik Goyal
M.Tech(Microwave Engineering)
Final Year (1201468505)
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Guide By-
Abhishek Srivastava
Assistant Professor
SRSMCET, Bareilly

2. Topics to be covered
 What is an optical nantenna
 Need of optical nantenna
 Applications of optical nantenna
 Base papers
 Problem identification
 Proposed work
 Designs & results
 Final design
 Formulae to calculate various parameters & final results
 Conclusion
 References
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3. Optical Nantenna
 Like microwave/RF antenna, it convert freely propagating
optical radiation into localized energy & vice versa
 It is made up of metallic or high-permittivity nanoparticles
 It basically origins from near field optics
 In a general way, when conventional antenna is operated at
optical frequency, then it is called an optical antenna
 It interacts with a receiver or transmitter in the form of a discrete
quantum system
 It can take various unusual forms like tip or a nanoparticles, etc
 It along with Tx/Rx must be regarded as a coupled system
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4. Need of optical Nantenna
Primary needs for communication are
 Faster & more secure networks
 Flexible & user friendly networks
 Low latency of transmission
 Low cost & high capacity
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5. Applications of Optical Nantenna
 Beam Steering applications
 In photo detection
 In photovoltaic
 In non-linear signal conversion
 In information processing
 In spectroscopic applications
 Medical imaging applications
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6. Concept of Beam Steering
 Beam steering is about changing the direction of the main lobe of
a radiation
 In optical systems, it is done by changing the medium through
which the beam is transmitted
 Beam steering plays an important role in ultra-fast switching and
scanning applications
 Traditionally, MEMS technology was used for the purpose of
beam steering applications that include complex arrangements
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7. Optical Yagi-Uda Nano-antenna: Base Papers
Fig.1: Optical Yagi-Uda nantenna consisting of gold nanrods used for feed, reflector & director
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8. Contd…
Fig.2: 5-element optical Yagi-Uda Nantenna driven by quantum dots
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9. Contd…
Fig.3: All dielectric optical Yagi-Uda Nantenna
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10. Problem Identification
Modern communication demands high speed data processing which
relies on the speed and bandwidth of special detectors and emitters
designed on the optical frequency. To justify the demand of todays’
high speed data communication and future Nano photonic circuits,
there is a need of proper materials & structures that a designer can use
to design required detectors and emitters at the optical frequencies.
Also, for potential beam steering applications, MEMS technology was
used which included a complex arrangement. There is a need of such
antenna that can direct the beam into a particular direction. According
to literature survey done, there are various optical antennas studied
like Yagi-Uda nantennas, log-periodic optical nantennas, spiral
nanoantennas, etc. but there is no any specification mentioned on the
basis of materials in the optical regime.
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11. Objective
To design an optimized optical Yagi-Uda nantenna at 1550nm for beam
steering and high speed data communication applications
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12. Proposed Work
 Elemental material based study is done with the help of various
designs
 Substrate based study is done
 Effect of number of elements is analyzed
 Different Structures are analyzed
 Finally, based on all studies & comparison made, an optimized design
has been proposed
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Factors & Parameters for
designs Parameters to be studied:
1. Material based study
2. Elements based study
3. Structure based study
 Factors to be analyzed:
1. Return Loss
2. Voltage Standing Wave Ratio

14. TABLE-I: Design Specifications
For Nanorods & Nanospheres
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Design Parameter Value (nm)
Operating Wavelength 1550
Operating Frequency 193.5 (THz)
Length of Reflector 442.875
Length of Feeder 387.5
Length of Director 344.44
Radius of Nanorods 25.835
Spacing between elements 258.30

15. TABLE-II: Details of Substrates
Used
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Substrate/Parameters Gallium Arsenide FR4 Silicon Glass
Relative Permittivity 12.9 4.4 11.9 5.5
Relative Permeability 1 1 1 1
Mass Density 5320 1900 2330 2500
Carrier Mobility High Low Low Low
Resistive Device
Parasitics
Low High High High

16. Design-I
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Fig.4: 3-element optical Yagi-Uda Nantenna

17. Result
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Fig.5: S11 when Gold nantenna & Silicon substrate is used

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Fig.6: Comparison of S11 when Gold nantenna and Silicon & Gallium Arsenide substrates are used

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Fig.7: Comparison of S11 when Silver nantenna and Silicon & Gallium Arsenide substrate are used

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Fig.8: Comparison of S11 when Gold & Silver nantenna and Gallium Arsenide substrate is used

21. Design-II
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Fig.9: 4-element optical Yagi-Uda Nantenna

22. Results
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Fig.10: Comparison of S11 when Gold & Silver nantenna and Gallium Arsenide substrates is used

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Fig.11: Comparison of S11 when Gold nantenna and Silicon & Gallium Arsenide substrate
are used

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Fig.12: Comparison of S11 when Silver nantenna and Silicon & Gallium Arsenide substrate
are used

25. Design-III
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Fig.13: 5-element optical Yagi-Uda Nantenna

26. Results
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Fig.14: Comparison of S11 when Gold nantenna and Silicon & Gallium Arsenide substrate
are used

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Fig.15: Comparison of S11 when Silver nantenna and Silicon & Gallium Arsenide substrate
are used

28. Design-IV
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Fig.16: 7-element optical Yagi-Uda nantenna

29. Results
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Fig.17: Comparison of S11 when Gold nantenna and Silicon & Gallium Arsenide substrate
are used

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Fig.18: Comparison of S11 when Silver nantenna and Silicon & Gallium Arsenide substrate
are used

31. Design-V
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Fig.19: 5-element all dielectric optical Yagi-Uda nantenna

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Fig.20:Graph showing comparison based on substrates for all dielectric optical Yagi-Uda nantenna
Results

33. Table-III: Design Spacing For
Circular Loop Yagi-Uda Nantenna
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Design Parameter Value (nm)
Operating Wavelength 1550
Operating Frequency 193.5 (THz)
Radius of Reflector 259.02
Radius of Feeder 193.75
Radius of Director(s) 172.28
Spacing between elements 155

34. Design-VI
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Fig.21:8-element circular loop optical Yagi-Uda nantenna

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Fig.22:Top view of 8-eleement circular loop optical Yagi-Uda nantenna

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Results
Fig.23:Graph showing comparison based on element material for 8-element circular loop optical Yagi-Uda
nantenna

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Fig.24:Graph showing comparison based on substrates for 8-element circular loop optical Yagi-Uda
nantenna

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Final Design
Fig.25:Finally optimized design with 9-element optical Yagi-Uda nantenna

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Results
Fig.26:Return Loss of finally optimized design

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Fig.27:VSWR of finally optimized design

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Fig.28: 2D plot of finally optimized design

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Fig.29: 3D plot finally optimized design

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Formulae to calculate various
parameters
If we have return loss, we can calculate the following
parameters directly:
Reflection Coefficient
VSWR
Through Power
Average Power
Reflected Power
( Re /20)
10 turnloss
 
2
100(1 )  
2
100* 
( Re /20)
( Re /20)
[1 10 ]
[1 10 ]
turnloss
turnloss





2
Re (1 )avP turnloss  

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Table-IV: Values of finally
calculated parameters
Parameters Calculated Result
Reflection Coefficient 0.00804
Voltage Standing Wave Ratio 1.0081
Average Power 41.89%
Through Power 99%
Reflected Power 0.006%

45. Conclusion
 Gold and silver are chosen to make the comparison for the elemental
material study
 Suitable number of directors has been chosen to get the appropriate results.
 Suitable material has been decided by comparing silicon, gallium arsenide,
glass, FR4 epoxy, etc.
 Analysis of different structures have been carried out
 After all the comparison, an optimized design has been proposed
 Optimized design can be used for the mentioned applications as Yagi-Uda
antenna is a directive antenna & can direct the beam in a particular
direction. This can eliminate the need of MEMS technology that was
including a complex arrangement for beam steering.
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46. References
• Ivan S. Maksymov, et.al., “Optical Yagi-Uda Nanoantennas”,
Nonlinear Physics Centre for Ultrahigh Bandwidth Devices for
Optical Systems,ACT 0200, April 2012
• Javier Alda, Jose M Rico-Garcia, Jose M Lopez-Alonso, G Boreman,
“Optical antennas for nano-photonic applications”, Institute of
Physics Publishing, 2005
• Holfer F. Hofmann, Terukazu Kosako, Yutaka Kadoya, “Design
Parameters for a nano-optical Yagi-Uda antenna”, Graduate School of
Advanced Sciences of Matter, 2007
• Lukas Novotny, “Optical Antennas”, Review Article, 2010
• Lukas Novotny, Niek van Hulst, “Antennas for light”, Nature
Photonics, Review Article, 2011
• Daniel Dregley, Richard Taubert, Jens Dorfmuller, Ralf Vogelgesang,
Klaus Kern, Harald Giessen, “3D Optical Yagi-Uda Nanoantenna
Array”, Research Article, Nature Communications, 2011
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