Dynamic range in terahertz time-domain transmission and reflection spectroscopy

Area of Science:

• Spectroscopy
• Terahertz (THz) Science
• Materials Analysis

Background:

• Terahertz (THz) time-domain spectroscopy is a powerful technique for material characterization.
• Accurate determination of the absorption coefficient is crucial for quantitative analysis.
• Understanding the dynamic range of detectable absorption is essential for reliable THz measurements.

Purpose of the Study:

• To present a quantitative method for identifying the dynamic range of the detectable absorption coefficient in terahertz time-domain spectroscopy.
• To differentiate the factors limiting the detectable absorption coefficient in transmission versus reflection measurements.

Main Methods:

• Analysis of transmission terahertz time-domain spectroscopy data.
• Quantitative assessment of signal dynamic range in transmission measurements.
• Evaluation of scan-to-scan reproducibility in reflection measurements.

Main Results:

• The largest detectable absorption coefficient in transmission measurements is dictated by the dynamic range of the terahertz signals.
• The largest detectable absorption coefficient in reflection measurements is limited by the scan-to-scan reproducibility of the terahertz signal.

Conclusions:

• A quantitative method for determining the dynamic range of detectable absorption coefficients in THz-TDS has been established.
• The findings provide critical insights into the limitations of absorption coefficient determination in both transmission and reflection THz spectroscopy.
• This work enhances the accuracy and reliability of quantitative analysis in terahertz spectroscopy.