Accurate thickness measurement using a single terahertz pulse obtained in ambient atmosphere

Abstract

Terahertz (THz) radiation suffers severe signal loss due to the high absorptivity of water vapor abundant in normal atmosphere, greatly limiting its potential in noninvasive material characterization. We propose a novel THz signal processing method that enables effective extraction of hidden sample information leading to accurate thickness determination. The thicknesses of multiple silicon wafers are measured using only a single THz pulse obtained in ambient atmosphere without any prior sample information. The results verify our proposed approach to achieve accurate and precise characterization of materials in a realistic environment.