This thesis reports the findings of terahertz photomixer spectroscopy performed on plasmonic grating-gate detectors made from high mobility two-dimensional electron gas (2DEG) material. In recent years, these detectors have seen significant improvements in sensitivity and currently exhibit a noise equivalent power of 10^-8 W/sqrt(Hz) However, further improvements are essential for these detectors to become truly useful; the ultimate goal being a NEP < 10^-10 W/sqrt(Hz) To this end, it is necessary to understand the physical properties of the mechanism underlying the detectors photoresponse, namely plasmons. Although two-dimensional plasmons were first observed in semiconductors in 1978, to date, their physical properties, for example scattering and absorption cross section, are relatively unknown. The primary purpose of this work is to develop a measurement system capable of revealing these properties and utilize this system to understand the absorption of radiation by two-dimensional plasmons. By no means will the study of plasmonic properties using this system end when this work is completed. Rather, this work lays the foundation for years of future research in this field.
Sandia National Laboratories
Level of Degree
Electrical and Computer Engineering
First Committee Member (Chair)
Second Committee Member
Barrick, Todd. "Terahertz photomixing spectroscopy of two-dimensional semiconductor plasmons." (2008). https://digitalrepository.unm.edu/ece_etds/27