Polarization modulation time-domain terahertz polarimetry.

Area of Science:

• Terahertz (THz) spectroscopy and optics
• Metrology and precision measurement

Background:

• Accurate characterization of polarization states is crucial for THz applications.
• Existing techniques may lack precision or cover limited frequency ranges.

Purpose of the Study:

• To develop and validate a high-precision polarization modulation technique for measuring polarization rotations.
• To achieve accurate characterization of elliptical polarization in the 0.1 to 2.5 THz range.

Main Methods:

• Utilizing a polarization modulation technique with a motorized rotating polarizer (~ 80 Hz).
• Employing a lock-in detection method for precise measurement of polarization modulation.
• Developing a detailed mathematical framework for data analysis.

Main Results:

• Achieved high accuracy (0.050°, 900 μrad) and precision (0.02°, 350 μrad) for small polarization rotation angles.
• Demonstrated the capability to fully characterize elliptical polarizations.
• Validated measurements across the 0.1 to 2.5 THz frequency spectrum.

Conclusions:

• The presented polarization modulation technique offers superior precision for THz polarization measurements.
• This method provides a robust tool for characterizing complex polarization states in the THz domain.
• The technique is applicable for a broad range of scientific and technological applications in the THz frequency range.