Research on chiral substances based on polarization detection array

Although chiral enantiomers have similar physical properties, they often exhibit diametrically opposite pharmacological activities and physiological functions. Therefore, research on its identification, analysis, and optical properties is of critical importance in fields such as biomedicine and life sciences. Current research on chiral substances based on traditional terahertz time-domain spectroscopy (THz-TDS) focuses mainly on absorption spectrum analysis, often neglecting their chiral characteristics and making it difficult to identify chirality. This paper investigates the optical properties of six typical chiral materials using a polarization THz-TDS based on a 2× 2 gallium arsenide photoconductive antenna. The experimental results show that chiral enantiomers exhibit consistent characteristic absorption peaks in the THz band, making it impossible to identify their chirality. Even chiral substances with different molecular structures can exhibit similar absorption peaks due to different vibration modes. The different responses of chiral substances to polarized light make the polarization parameters have molecular configuration sensitivity, and show differences that can be used for chiral recognition between enantiomers and between different chiral substances.