Mid-IR Plasmonics, Cavity Coupled Excitations, and IR Spectra of Individual Airborne Particulate ...

182 Pages·2017·6.23 MB·English

Mid-IR Plasmonics, Cavity Coupled Excitations, and IR Spectra of Individual
Airborne Particulate Matter

DISSERTATION

Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy
in the Graduate School of The Ohio State University

By
Antriksh Luthra, B.E., M.S.
Graduate Program in Mechanical Engineering

The Ohio State University
2017

Dissertation Committee:
Prof. James V. Coe, Advisor
Prof. Vish V. Subramaniam, Co-Advisor
Prof. Fernando L. Teixeira
Prof. Barbara E. Wyslouzil
Copyrighted by
Antriksh Luthra
2017
Abstract

With the advances in plasmonics, new fields have evolved involving the mixing of light
with various states like Surface Plasmons (SPs), Surface Phonons (SPh), molecular
emitters or resonators, and wavelength scale cavities. This work concentrates on the
interaction of infrared (IR) light with SPs, cavity modes, and molecular vibrations. In the
first chapter, the field of Plasmonics is introduced from a classical and a quantum
mechanical perspective and a comparison of both is presented. In Chapter 2, the interaction
of cavity modes with vibrations is discussed. Briefly, when IR light is illuminated upon an
etalon, its fringes disperse as function of angle. If there is a dielectric in a cavity having a
vibrational transition in the fringe region, it leads to a strong interaction that gives rise to a
Rabi splitting[1]. Data was obtained from collaborators at the U.S. Naval Research
Laboratory (NRL) and a derivation for the dispersion of etalon cavity modes was carried
out to model the peak positions of the fringes. In Chapter 3, the excitation of Surface
Plasmons Polaritons (SPPs) on metal bi-gratings is discussed. The resonance condition
occurs when the momentum of the IR light parallel to the surface plus the grating vector
match the momentum of the SPP. Experiments were performed in the Γ(cid:1850) space ((cid:1863) = 0)
(cid:3052)
and the resonance peak positions were modeled with SPP momentum matching equations.
In Chapter 4, the application of plasmonics in the mid-IR frequency range that overlaps
with the frequencies of molecular vibrations is explored. The plasmonic mesh has
interesting optical properties, it focuses more light in the holes and that leads to an
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enhancement of the IR spectra of a particle trapped in the mesh hole. In this work,
plasmonic mesh is used to study airborne particles that are usually difficult to study using
FTIR spectroscopy due to strong Mie scattering effect. Respiring dust particles of ~4
microns size has significant negative health consequences. Different environments pose
different health hazards. Chemical insights of such dust collected from four very different
environments: lab air, home air filter, the 11 September 2001 WTC event and the
International Space Station is reported. These particles were collected by pumping air
through plasmonic metal films with a 12.6 μm square lattice of 5 μm square holes, enabling
us to record “scatter-free” IR absorption spectra of individual particles whose peaks reveal
their IR active components. In Chapter 5, statistical methods such as single value
decomposition (SVD) and support vector machine (SVM) informed with a Mie-
Bruggeman model [2, 3] is presented, analyzing the spectral data from different dust
environments.
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Dedicated to my parents and my grandparents.

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Acknowledgments

I would like to thank my advisor, Prof. James V. Coe, for his continuous support and
encouragement. I joined the research group as a Mechanical Engineer with an enthusiasm
towards the physical sciences. I am very thankful to him for embracing me into his group.
The valuable training I received from him will help me enrich my future scientific
endeavors, and I am truly grateful.
I would like to thank my co-advisor, Prof. Vish V. Subramaniam for his support and
guidance, especially during the early stages of my graduate program. I am also very grateful
to him for providing me his recommendation that helped me secure two scholarships at the
Ohio State University.
Next, I would like to thank my dear friend and colleague, Aruna Ravi. It was a pleasure
working with her on the plasmonics and dust projects. With her encouragement, I took
electromagnetics, optics and metamaterials classes in Electrical and Computer
Engineering, and I was very fortunate to study two of these courses under the very
insightful, Prof. Fernando L. Teixeira. I would like to sincerely thank him for sharing his
valuable teachings during the duration of the coursework, and also for agreeing to be on
my candidacy and dissertation committee.
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I would like to thank Prof. Barbara Wyslouzil. I have always had very pleasant
interactions with her, and I am grateful that she has agreed to be a part of my dissertation
committee.
I would like to thank Prof. Eric Fosler-Lussier. I am grateful for his presence during my
oral defense as a Graduate Faculty Representative.
I would like to thank Prof. Walter Lempert. He was very encouraging and I felt very
fortunate to take an optics class with him. I am grateful that he was in my PhD candidacy
committee.
I would like to thank the MAE Graduate Program Administrators, Janeen Sands and Nick
Breckenridge for their help during the entire duration of my graduate program.
I would like to thank the Robert H. Edgerley Environmental Toxicology Fellowship Fund
for supporting my research during the academic year 2015-2016, and the National Science
Foundation (grant number CHE 1213293) for supporting me as a Graduate Research
Associate during the academic years 2011-2015.
I would also like to acknowledge the students I worked with during my time in the Coe
group: Katie Cilwa, Marvin Malone, Sirui Li, Steven Nystrom, Chuck Loney, David Lioi,
Lindsey Shaffer, Zech Thompson, and Justin Erwin. It was great working with all of them!
Finally, I would like to thank my parents, Meena Luthra and V. K. Luthra, my brother
Akash Luthra, and my dearest grandfather Mangal Das Luthra for their love and support.
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Vita

2007................................................................B.E. Mechanical Engineering,
Visvesvaraya Technological University
2010................................................................M.S. Aerospace Engineering,
University of Texas at Arlington
2011 to 2015 ..................................................Graduate Research Associate,
Ohio State University, Columbus
2015 to 2016 ..................................................Edgerley Fellow,
Ohio State University, Columbus

Publications

- A. Ravi, A. Luthra, F. L. Teixeira, and J. V. Coe, “Predicting Infrared Spectra of
Atmospheric Dust Samples of Mixed Composition Particles” Proc. 2nd Int. Conf. on
Atmospheric Dust, 2016., ISSN: 2283-5954
- A. Luthra, A. Ravi, S. Li, S. V. Nystrom, Z. Thompson, and J. V. Coe, “Dust Library of
Plasmonically Enhanced Infrared Spectra of Individual Respirable Particles” Applied
Spectroscopy. 2016 Jul 20:0003702816653126.
- A. Luthra, A. Ravi, and J. V. Coe, “The Dust Library: Enhanced Infrared Spectra of
Individual Respirable Dust Particles”, Proc. ICES 248, 12-16 July 2015, Bellevue,
Washington.
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- A. Ravi, A. Luthra, F. L. Teixeira, P. R. Berger, and J. V. Coe, “Tuning the plasmonic
extinction resonances of hexagonal arrays of Ag nanoparticles”, Plasmonics, DOI:
10.1007/s11468-015-9963-9, May 12 2015.
- J. V. Coe, D. B. Lioi, L. Shaffer, M. A. Malone, A. Luthra, and A. Ravi, “Plasmonic
Spectra of Individual Subwavelength Particles Under the Infrared Microscope: Cells and
Airborne Dust”, Proc. SPIE 8957, Plasmonics in Biology and Medicine XI, 89570A,
2014.
- Ravi, A; Malone, M. A.; Luthra, A; Lioi, D.; Coe, J. V.; “Spectral Challenges of
Individual Wavelength-Scale Particles: Strong Phonons and their Distorted Lineshapes”,
Phys. Chem. Chem. Phys., 2013, 15, 10307-10315.
- Malone, M. A.; Luthra, A.; Lioi, D.; Coe, J. V.; “Developing Plasmonics Under the
Infrared Microscope: From Ni Nanoparticle Arrays to Infrared Micromesh”, J. Phys.
Chem. Lett. Volume: 3 Issue: 13 Pages: 1774-1782 DOI: 10.1021/jz300499a, July 5
2012.
- Malone, M. A.; Cilwa, K. E.; Luthra, A. et al.; “Plasmonics under the Infrared
Microscope: Sensing and Spectra of Single Particles Using Metal Film Hole Arrays”,
Conference: Symposium on Photonics and Optoelectronics (SOPO), 2012.

Fields of Study

Major Field: Mechanical Engineering
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Table of Contents

Abstract ............................................................................................................................... ii
Acknowledgments............................................................................................................... v
Vita .................................................................................................................................... vii
Publications ....................................................................................................................... vii
Fields of Study ................................................................................................................. viii
Table of Contents ............................................................................................................... ix
List of Tables ................................................................................................................... xiii
Chapter 1: Introduction to Plasmonics ..................................................................... 1
1.1 Volume Plasmons ............................................................................................... 2
1.2 Surface Plasmons................................................................................................ 4
1.2.1 Classical Description of Surface Plasmon Polaritons (SPPs) .................. 4
1.3 Dielectric Function (Drude Dielectric Model) ............................................... 11
1.4 SPP Dispersion.................................................................................................. 12
1.5 Electric Field Lines of SPP .............................................................................. 16
1.6 Quantum Mechanical (QM) Description ....................................................... 17
1.6.1 Mixed State of Surface Plasmon and Light ............................................ 19
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