Time-domain data truncation method for improving terahertz absorption spectrum reproducibility

The confounding nature of the etalon-feature in THz frequency-domain spectra can be eliminated by truncating the time-domain data before the echoes. However, the spectra features are sensitive to the window length used to truncate the raw data. In this paper, we presented the impact of random truncation on the THz absorption features of L-Glutamine (Gln) and then put forward with an optimized time-domain data truncation (TDDT) method to improve the spectra reproducibility. Samples consist of Gln at three different concentrations were measured with THz-TDS to assess our method.