Nonlinear Optical Signatures of Electronic Quantum Tunneling Effects in Nanoplasmonic Systems
Abstract
The objective is to validate the Quantum Conductivity Theory (QCT), a quantum nano-plasmonic analysis of electromagnetic scattering in nanomaterials. Validation of the QCT is based upon experiments designed to measure the second-harmonic and third-harmonic signals from metal-insulator-metal (MIM) structures, and in particular to find a quantum tunneling signature in the nonlinear harmonics that can be several orders of magnitude larger than the intrinsic material nonlinearities. The samples will be fabricated using a flat substrate covered with a uniform metal film. Few-angstrom thick alumina (Al2O3) or titania (TiO2) deposited over the metal film act as a dielectric spacer layer. Gold nanoparticles from various sources are dispersed on the thin film, dielectric surface, and the sample is placed under a microscope and illuminated with tunable, intense laser pulses. The interplay between the experimental design and the electromagnetic simulations will be an important aspect to validating QCT. Advanced exploratory experiments are designed to examine MIM nanorod structures fabricated using different strategies. Our new design concept eliminates the need for an antenna with its associated impedance matching issues and intrinsic propagation losses. One nanorod fabrication approach uses an anodic alumina template (AAT) to fabricate single MIM nanorods. Metallic nanorods are grown inside the nanoholes via assisted self-assembled growth. Within the templates ALD dielectric films will be deposited, separating the two metallic rods by a few � spacer layer. The second fabrication method can produce large area MIM using oblique angle deposition techniques. By interrupting the growth with an atomic layer deposition (ALD) deposition process the MIM nanorod is grown over a substrate. The substrate can be patterned to control the nanorod density. Optical and electrical response measurements will be conducted on the large area devices to determine their potential for future photodetection or energy harvesting applications.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 12, 2017
- Source ID
- W911NF1510178
Entities
People
- Joseph Haus
Organizations
- Army Contracting Command
- United States Army
- University of Dayton