title: Investigation of Dielectric Properties of Polymers and their Discrimination Using Terahertz Time-Domain Spectroscopy with Principal Component Analysis.
abstract: Polymers are among the most commonly used materials in our everyday life. They are generally transparent to terahertz (THz) radiation, but are quite difficult to differentiate using optical techniques as few or no characteristic features exist in the spectral range of <2.0 THz for small and portable radiation systems. In this work, we report experimental measurement of refractive indices and absorption coefficients of styrene acrylonitrile (SAN) and Bakelite in the spectral range of 0.2-2.0 THz for the first time. Additionally, we demonstrate that by combining principle component analysis (PCA) with THz time-domain spectroscopy one can differentiate such polymers. In this analysis, the first three principle components PC1, PC2, and PC3 depict >94% variance with a distribution of 72.45%, 11.52%, and 9.38%, respectively.
authors: National Institute of Lasers and Optronics, Nilore, Islamabad, Pakistan.
authors: Muhammad
authors: M
authors: Mumtaz
authors: National Institute of Lasers and Optronics, Nilore, Islamabad, Pakistan.
authors: Ahsan
authors: A
authors: Mahmood
authors: National Institute of Lasers and Optronics, Nilore, Islamabad, Pakistan.
authors: Sabih D
authors: SD
authors: Khan
authors: National Institute of Lasers and Optronics, Nilore, Islamabad, Pakistan.
authors: M Aslam
authors: MA
authors: Zia
authors: National Institute of Lasers and Optronics, Nilore, Islamabad, Pakistan.
authors: Mushtaq
authors: M
authors: Ahmed
authors: National Institute of Lasers and Optronics, Nilore, Islamabad, Pakistan.
authors: Izhar
authors: I
authors: Ahmad
keywords: PCA; TDS; THz; Terahertz; discrimination of polymers; principal component analysis; time-domain spectroscopy