Ultrawideband and High-Resolution Terahertz Spectroscopy: Structural Identification of Glucose

We report on the development of an ultrawideband and high-resolution THz spectroscopic system, which operates over a frequency range of 2-13.5 THz. This work goes beyond conventional THz spectroscopic measurements and demonstrates the capacity to differentiate D- and L-glucoses, which have the same molecular conformation and crystal structure. Furthermore, this system facilitates the structural identification of glucose microcrystals, which exists in alpha- and beta-forms, revealing that L-glucose microcrystals are formed of a mixture of alpha- and beta-D-glucose with approximately equal weight.