Nanoplasmonics and silicon nanophotonics devices for sensing applications

Gartia, Manas Ranjan

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Description

Title

Nanoplasmonics and silicon nanophotonics devices for sensing applications

Author(s)

Gartia, Manas Ranjan

Issue Date

2014-09-25

Director of Research (if dissertation) or Advisor (if thesis)

Liu, Gang Logan

Doctoral Committee Chair(s)

Liu, Gang Logan

Committee Member(s)

• Uddin, Rizwan
• Stubbins, James F.
• Ruzic, David N.

Department of Study

Nuclear, Plasma, & Rad Engr

Discipline

Nuclear, Plasma, Radiolgc Engr

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• Plasmonics
• Nanophotonics
• Nanohole array
• Biosensing
• Optical spectroscopy
• surface enhanced Raman spectroscopy (SERS)
• Raman
• Solar cell
• Fluorescence imaging
• Cell imaging

Abstract

Nanophotonics deals with the interaction of light with matter in nanometer scale. One of the subsets of nanophotonics is nanoplasmonics, which deals with manipulation of light using the unique optical properties of metal nanostructures. Manipulation of light in nanoscale using properties of surface plasmon will make it possible to accomplish a myriad of applications ranging from global security to healthcare and environmental sensing. This thesis studies silicon-based nanophotonics and noble metal based nanoplasmonics devices, and explores their utilities for energy, sensing, and photonics applications. Three dimensional (3D) sub-wavelength tapered periodic hole array plasmonic structure has been designed and fabricated. In contrast to the surface plasmon polariton (SPP) mediated extraordinary optical transmission (EOT), the proposed structure relies on the localized surface plasmon (LSP) enhanced optical transmission. The advantage of LSPs is that the enhanced transmission at different wavelengths and with different dispersion properties can be tuned by controlling the size, shape and materials of the 3D holes. The tapered geometry will funnel and adiabatically focus the photons on to the sub-wavelength plasmonic structure at the bottom, leading to a large local electric field and the enhancement of EOT (due to radiative coupling of surface plasmons). The design principle of such devices for surface enhanced Raman spectroscopy (SERS) applications based on the classical electromagnetic simulations (Finite Difference Time Domain, FDTD) and the quantum mechanical density functional theory (DFT) has been performed. Due to large transmission and reflection resonance wavelength shifts upon binding of molecules on the above flexible, high throughput, large area 3D plasmonic device, the device showed highest ever reported sensitivity of 46,000 nm per refractive-index unit and unprecedented figure of merit of 1,022. The utility of the sensor for highly sensitive refractive-index sensing, DNA hybridization detection, protein-protein interaction and integration to portable microfluidics device for lab on chip applications have been achieved. The thesis discusses how to transform the nanoplasmonic spectroscopy sensing to become colorimetric sensing with requiring only naked eyes or ordinary visible color photography, eliminating the need for precision spectrometer or fluorescence labeling. The device can also be utilized for preparing beyond diffraction limit DNA/proteomics microarray using plasmonic nanolithography techniques. The second part of thesis addresses an important scientific question – how to increase long range energy transfer efficiency in nanoscale. Energy transfer between light and matter (e.g. photons-molecule, molecule-molecule) is essential in sustaining life in nature. One of such examples is photosynthesis. In contrast to the efficient energy transfer processes in the living system (e.g. resonance energy transfer efficiency in reaction center of light harvesting complex for photosynthesis process is over 90%), man-made photonics and plasmonics system are impaired with low energy transfer efficiencies. This poses a serious challenge for the realization of efficient plasmonic devices for signal guiding, modulation and active information processing on nanoscale. Although, many near field energy transfer schemes such as Förster Resonance Energy Transfer (FRET), Dexter Energy Transfer (DET), and Plasmon Resonance Energy Transfer (PRET) have been explored, they are mostly short-ranged (< 100 nm) and the energy transfer efficiency decreases drastically with distance. This thesis proposes a new energy transport route through a hybrid plasmonic-photonic system coupling the dipole-photonic-plasmonic resonance energy transfer (DiP-PRET) to achieve over 90% energy transfer efficiency.

Graduation Semester

2013-12

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Copyright 2013 Manas Ranjan Gartia

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