Terahertz time domain spectroscopy for chemical identification

In this paper, we performed time domain terahertz spectroscopy (THz- TDS) of two drugs (Paracetamol and Ibuprofen). The THz- TDS is based on a Ti:Sapphire femtosecond laser and a two low-temperature grown GaAs photoconductive antennas for emission and detection of terahertz radiation. A working window from 0.2 to 2.5 THz was obtained. First, spectral response of water vapor absorption is reported and compared to HITRAN database. A good agreement was observed. Finally, the THz spectra of two commercial drugs (paracetamol and ibuprofen) were performed and absorption peaks were observed. Different behavior of the spectrum of both drugs was clearly found. Further simulations are under study to identify the origin of those peaks as well as enhancement of the experimental setup.