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Antriksh Luthra PhD Dissertation.pdf (6.23 MB)

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

Luthra, Antriksh
http://orcid.org/0000-0001-7228-7483
http://rave.ohiolink.edu/etdc/view?acc_num=osu148362252748271

Abstract Details

2017, Doctor of Philosophy, Ohio State University, Mechanical Engineering.
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. 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 GX space (ky=0) 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 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 is presented, analyzing the spectral data from different dust environments.
James Coe (Advisor)
Vish Subramaniam (Committee Co-Chair)
Fernando Teixeira (Committee Member)
Barbara Wyslouzil (Committee Member)
Electromagnetics; Optics; Physical Chemistry; Physics; Quantum Physics; Toxicology
Plasmonics; IR Spectroscopy; Particulate Matter

Recommended Citations

Citations

  • Luthra, A. (2017). Mid-IR Plasmonics, Cavity Coupled Excitations, and IR Spectra of Individual Airborne Particulate Matter [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu148362252748271

    APA Style (7th edition)

  • Luthra, Antriksh. Mid-IR Plasmonics, Cavity Coupled Excitations, and IR Spectra of Individual Airborne Particulate Matter. 2017. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu148362252748271.

    MLA Style (8th edition)

  • Luthra, Antriksh. "Mid-IR Plasmonics, Cavity Coupled Excitations, and IR Spectra of Individual Airborne Particulate Matter." Doctoral dissertation, Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu148362252748271

    Chicago Manual of Style (17th edition)

osu148362252748271
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© 2017, all rights reserved.
This open access ETD is published by The Ohio State University and OhioLINK.