Cover story: Ji X Y, Sun S, Zhang Y. Recognition of chiral substances by terahertz circular dichroism[J]. Opto-Electron Eng, 2024, 51(5):240005

Biomolecules with different chirality have different or even opposite biological and pharmacological activities. Since that the vibrational and rotational capabilities of numerous biomolecules fall within the terahertz band, terahertz spectroscopy is regards as a promising tool in biological and pharmaceutical research. It can reveal the three-dimensional arrangements, the low-frequency absorption characteristics, and the configurations of collective vibrational modes of biomolecules. 

Recently, Professor Zhang Yan's team from Capital Normal University proposed to employed the linearly polarized terahertz time-domain pectroscopy to solve the circular dichroism problem of chiral substances, and achieved recognition of chiral molecules of ibuprofen. They theoretically constructed a circularly polarized Jones matrix using a linearly polarized Jones matrix model. They also calculated the transmission circular dichroism spectrum of the sample based on the difference in transmittance of circularly polarized light, offering a useful technique for describing various chiral compounds.