학술논문

Characterization of Thin Film Liquids by Multilayer Structure in THz Time Domain Reflection Spectroscopy
Document Type
Conference
Source
2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) Infrared, Millimeter, and Terahertz Waves (IRMMW-THz), 2019 44th International Conference on. :1-2 Sep, 2019
Subject
Aerospace
Bioengineering
Communication, Networking and Broadcast Technologies
Components, Circuits, Devices and Systems
Engineered Materials, Dielectrics and Plasmas
Fields, Waves and Electromagnetics
Photonics and Electrooptics
Liquids
Nonhomogeneous media
Reflection
Geometry
Spectroscopy
Sensitivity
Optical variables measurement
Language
ISSN
2162-2035
Abstract
The characterization of thin film liquids is not as straightforward as bulk materials, as it requires accurate control of the thin film thickness and precise measurements of the amplitude and phase of the signals. We propose a multilayer structure for terahertz (THz) time domain reflection spectroscopy (TDRS) characterization of thin film liquids, the equations for this geometry are derived and the water-ethanol mixtures with various concentrations are measured, the refractive indices and absorption coefficients extracted from the proposed geometry and ordinary bulk reflection geometry match well. This work demonstrates that the proposed multilayer structure can be used to extract the optical properties of liquids by using a tiny amount of the sample, it can be potentially applied to characterize valuable biological aqueous solutions in the future.