Researcher(s)
- Benjamin Putnam, Physics, Lafayette College
Faculty Mentor(s)
- Xi Wang, Materials Science and Engineering, University of Delaware
Abstract
Electromagnetic radiation in the Terahertz range is underutilized in current technologies, and metamaterials with engineered properties are being fabricated to manipulate Terahertz radiation in useful ways. We used time domain Terahertz spectroscopy with three polarizers to characterize a metamaterial actuated by temperature dependent vanadium dioxide (VO2). Time domain Terahertz spectroscopy (TDTS) aims a beam of Terahertz light at the VO2 sample; that beam interacts with the sample and thus is modulated by the sample in some way. VO2 undergoes a phase transition at approximately 68°C and also exhibits a change in optical properties after this phase transition. By varying temperature, the structure of the VO2 actuated metamaterial can exhibit left- or right-hand chirality, thus modulating the polarization of the Terahertz light. By obtaining the Jones matrix of the vanadium dioxide-actuated sample, we can calculate the azimuthal rotation angle and ellipticity angle of the outgoing Terahertz light as a function of temperature. Using a series of data processing techniques including zero padding, we have further prepared the data for comprehensive understanding of the metamaterial’s properties and for future use in publications. Current analysis shows the metamaterial’s strong Terahertz polarization modulation with temperature change.