Terahertz Time Domain Spectroscopy via Plasma Generation and Air Biased Coherent Detection
Conference Year
January 2020
Abstract
Terahertz (THz) spectroscopy is a powerful tool used to noninvasively, nondestructively gather information at the atomic level. The THz gap is difficult to access because of its extremely low energy, however crystals such as zinc telluride (ZnTe) and gallium phosphide (GaP) can be used along with 800 nm optical light to generate and detect pulses in the range of 0.1-8 THz. While this bandwidth is sufficient for many measurements (i.e. low frequency molecular dynamics in condensed matter), a larger bandwidth could open the door to an abundance of new information. Specifically, characterizing phonons requires the higher time resolution that stems from the broader bandwidth. In an attempt to achieve a range of 1-30 THz, four wave mixing via plasma generation and an air biased coherent detection (ABCD) method will be used. These methods eliminate a generation and detection medium, and therefore phonon absorption, which is the limiting factor of crystal-based methods. Coupling this broadband spectrometer with various sample conditions (such as controlling the temperature or optically exciting the sample) can lead to a wide variety of new experimental techniques.
Primary Faculty Mentor Name
Michael Ruggiero
Status
Graduate
Student College
Graduate College
Program/Major
Chemistry
Primary Research Category
Engineering & Physical Sciences
Terahertz Time Domain Spectroscopy via Plasma Generation and Air Biased Coherent Detection
Terahertz (THz) spectroscopy is a powerful tool used to noninvasively, nondestructively gather information at the atomic level. The THz gap is difficult to access because of its extremely low energy, however crystals such as zinc telluride (ZnTe) and gallium phosphide (GaP) can be used along with 800 nm optical light to generate and detect pulses in the range of 0.1-8 THz. While this bandwidth is sufficient for many measurements (i.e. low frequency molecular dynamics in condensed matter), a larger bandwidth could open the door to an abundance of new information. Specifically, characterizing phonons requires the higher time resolution that stems from the broader bandwidth. In an attempt to achieve a range of 1-30 THz, four wave mixing via plasma generation and an air biased coherent detection (ABCD) method will be used. These methods eliminate a generation and detection medium, and therefore phonon absorption, which is the limiting factor of crystal-based methods. Coupling this broadband spectrometer with various sample conditions (such as controlling the temperature or optically exciting the sample) can lead to a wide variety of new experimental techniques.