Increase the sensitivity of terahertz liquid detection using a triple attenuated total reflection probe

Area of Science:

• Spectroscopy
• Terahertz spectroscopy
• Materials science

Background:

• Terahertz attenuated total reflection (ATR) is crucial for liquid spectroscopic analysis.
• Conventional single internal reflection probes lack sensitivity and accuracy due to limited evanescent wave-sample interaction.

Purpose of the Study:

• To design and construct a novel terahertz ATR probe for enhanced liquid analysis.
• To improve sensitivity and detection accuracy in terahertz spectroscopic measurements of liquids.

Main Methods:

• Development of a terahertz ATR probe incorporating a triple internal reflection prism.
• Utilizing increased internal reflections to enhance evanescent wave-liquid interaction.
• Experimental measurement of optical constants and solvent identification.

Main Results:

• The triple internal reflection prism probe demonstrated high accuracy in measuring liquid optical constants.
• The probe successfully identified polar solvents like ethanol, water, isopropanol, and acetone.
• Achieved a three-fold increase in sensitivity compared to single internal reflection probes.

Conclusions:

• The developed terahertz triple ATR probe significantly enhances sensitivity and accuracy for liquid analysis.
• This advancement enables precise measurement of small compositional changes in solutions.
• The probe is effective for spectroscopic identification of polar solvents using terahertz wave absorption differences.