Effect of UV light on systematic errors in THZ-TDS spectroscopy

Terahertz Time-Domain Spectroscopy (THz-TDS) has become an extremely important technique to characterize the optical properties of materials of interest in this regime. Specifically, UV photoresponsive semiconductors (i.e. wide-bandgap semiconductors) have attracted an ever increasing attention due to their prospective application in reconfigurable devices. We report a systematic error due to the presence of UV photons in a TDS set up, and we describe a systematic correction to overcome this error and discuss a preliminary explanation for the observed effect. An additional experiment employing Carbon Quantum Dots (QDs) was carried out to verify the aforementioned corrective method.