Hygroscopicity of window materials using terahertz time-domain spectroscopy (THz-TDS)

Liquid spectroscopy allows analysis of chemical composition and provides a better understanding of the solvation dynamics of various types of liquid [1]. In liquid spectroscopy, window material is required to contain the liquid samples. A number of papers have been published on absorption coefficient of different types of window materials for liquid spectroscopy [1], [2], [3], however the hygroscopicity of the window material which could potentially increase the absorption coefficient of the window material has not been reported. This paper measures the hygroscopicity of different types of window materials used in terahertz liquid spectroscopy.