Utilizing multilayer structures to enhance terahertz characterization of thin films ranging from aqueous solutions to histology slides
Sun, Qiushuo, Kai Liu, Xuequan Chen, Xudong Liu, Ai Hernandezserrano, And E. M. M. A. Pickwell-Macpherson. “Utilizing multilayer structures to enhance terahertz characterization of thin films ranging from aqueous solutions to histology slides.” Optics Letters.
We propose a multilayer geometry to characterize thin film samples in reflection terahertz time domain spectroscopy. Theory indicates that this geometry has higher sensitivity compared to ordinary transmission or reflection geometries when characterizing both low and high absorption samples. Pure water and water-ethanol mixtures are measured to verify the characterization accuracy of the proposed geometry and its capability to measure trace liquids. Paraffin-embedded oral cancer tissues are imaged to further show how the proposed geometry enhances the sensitivity for solid low-absorptive films.