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...
We show that the transmission of a terahertz (THz) pulse through single-layer graphene is strongly
nonlinear. As the peak electric field of the THz pulse exceeds 50 kV/cm, the graphene becomes
increasingly transparent to the THz radiation. When field strength reaches 800 kV/cm, the increased
transparency corresponds to a two-fold...
We demonstrate that unidirectionally aligned, free-standing multi-walled carbon nanotubes (CNTs) exhibit highly anisotropic linear and nonlinear terahertz (THz) responses. For the polarization parallel to the CNT axis, strong THz pulses induce nonlinear absorption in the quasi-one-dimensional conducting media, while no nonlinear effect is observed in the perpendicular polarization configuration. Time-resolved...
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...
This dissertation is an exploration of the material response to Terahertz (THz) radiation. Specifically we will explore the ultrafast electron dynamics in the nonperturbative regime in semiconductors that have been patterned with nanoantenna arrays using broadband, high intensity, THz radiation. Three main semiconductor materials will be studied in this work....
Carbon nanotubes are the subject of intense interest in virtually every field, from medicine to
nano-scale electrical components. Multi-walled nanotubes exhibit a strong nonlinear response
to high-field strength terahertz radiation. This research uses terahertz pulses with field strength
exceeding 1 MV/cm generated by means of optical rectification utilizing a lithium...
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5 Acknowledgments
• I would like to thank Ali, Byounghwak, and Dr. Lee for all their help over the