Date of Degree


Document Type


Degree Name





Sang-Woo Seo

Committee Members

Roger Dorsinville

Maria C. Tamargo

Ioana Voiculescu

Muhammad Ali Ummy

Subject Categories

Electrical and Electronics | Other Electrical and Computer Engineering


Terahertz, Photoconductive, Antenna, Bow-tie, Thin film device


Terahertz (THz) wave (between 0.1 and 10 THz) is attracting a lot of attention due to its unique properties that are favorable to various applications. These include non-ionizing radiation, better resolution than a microwave, unique spectral absorption, and an ability to propagate through many types of materials. It has been intensively researched in sensing and imaging technology for a wide range of applications in areas such as biology, pharmaceutical, food and drug control, medical science, and security screening. Driven by mostly scientific research interests, the majority of THz systems are more focused on system performance rather than system size, integration, and cost. Many THz applications aforementioned would be benefit from the compact integration of THz devices and other types of functional devices.

This dissertation research focuses on developing a THz source based on heterogeneous thin film device integration. The demonstration shows a cost-effective integration approach and a feasibility to develop a THz integrated system that utilizes separately optimized LTG-GaAs based THz devices with other types of Si-based devices. The key aspect of the integration lies in the thin-film format of LTG-GaAs based THz devices, which allows their seamless integration on a final integration substrate and subsequent fabrication processes on the top of the THz devices. Using this approach, THz devices can be integrated on any host substrate (including organic and inorganic substrates), which gives a design freedom to enhance THz integrated system performances. Based on post-integration approach, the demonstrated method does not require significant modification of a host substrate technology. This allows THz functional devices to be integrated on various integration platforms including microfluidics, optics, and digital electronics. Intimate integration of THz devices with other functional devices will benefit a broad range of applications, which has limitations due to the current bulky THz systems.