We have investigated a second-order phase transition of the vortex lattice in thin-film Nd₁.₈₅Ce₀.₁₅CuO[subscript 4-y] from 1 mT to 1 T applied magnetic fields. The dc resistivity-current density data for each field exhibit critical scaling consistent with a second-order vortex-liquid to vortex-solid phase transition. The high-field data support the vortex-glass...
This thesis will cover my work relating to the developing field of terahertz (THz) science and technology. It will present experimental and theoretical studies investigating the optical and electrical properties of various material systems using novel THz imaging and spectroscopy techniques. Due to its low photon energy, THz imaging and...
This dissertation presents nonlinear terahertz (THz) properties of carbon nanomaterials investigated by time-resolved high-field THz spectroscopy. In order to determine THz characteristics of nanomaterials, we performed THz power spectrum measurement, THz raster imaging, THz time-domain spectroscopy (THz-TDS) and time-resolved pump-probe experiment on two different types of single layer graphene and...
In this dissertation, a series of studies in the field of terahertz (THz) science are presented, specifically using nonlinear THz spectroscopy. We exploit huge field enhancement and subwavelength confinement in plasmonic structures. There are three distinct projects which will be discussed: nonlinear THz spectroscopy using plasmonic induced transparency (PIT), THz-triggered...
We have developed simple and inexpensive laser systems
using grating-feedback diode lasers with electronic feedback to the
injection current. These grating-feedback lasers can be
continuously scanned up to 10 GHz and have a linewidth of 150 kHz.
The three electronic frequency-stabilization systems we developed
use polarization spectroscopy, etalon transmission and...
The optical response of metallic structures is dominated by the dynamics of their free electron plasma. Plasmonics, the area of optics specializing in the electromagnetic behavior of heterogeneous structures with metallic inclusions, is undergoing rapid development, fueled in part by recent progress in experimental fabrication techniques and novel
theoretical approaches....
The optical and electronic properties of amorphous oxide thin films depend crucially on chemical composition, and deposition process variations which give rise to sub-gap defect states. Consequently, there is a need for a reliable, high-throughput method to extract sub-gap defect densities of states in amorphous oxide thin films. We present...