Abstract

Time-domain terahertz spectroscopy typically uses mechanical delay stages that inherently suffer from non-uniform sampling positions. We review, simulate, and experimentally test, as a proof of principle, the ability of corrective cubic spline and Shannon re-gridding algorithms to mitigate the inherent sampling position noise. We experimentally confirm that sampling position uncertainty is not a leading source error in a modern time-domain terahertz spectrometer. Though modern systems are presently limited by other noise sources, our simulations and data suggest that re-gridding is an effective technique to improve the signal-to-noise ratio of a system limited by sampling position within the frequency range of 100 GHz to 2 THz. We also predict that re-gridding corrections will become increasingly important to both spectroscopy and imaging as THz technology continues to improve and higher frequencies become experimentally accessible.

© 2019 Optical Society of America

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