Polarizing interferometer for the unambiguous determination of the ellipsometric parameters

Area of Science:

• Optics and Photonics
• Spectroscopy
• Materials Science

Background:

• Ellipsometry is a powerful technique for characterizing thin films and surfaces.
• Traditional ellipsometry in the far-infrared (FIR) often requires complex setups involving retarders.
• Unambiguous determination of optical properties can be challenging in the FIR spectral range.

Purpose of the Study:

• To develop a novel polarizing interferometer-ellipsometer.
• To eliminate the need for retarder measurements in far-infrared ellipsometry.
• To enable unambiguous determination of ellipsometric parameters in the FIR.

Main Methods:

• A polarizing interferometer-ellipsometer was designed and constructed.
• The system integrates a Martin-Puplett interferometer with a wire-grid polarizer.
• Experimental validation was performed on a polyethylene sample.

Main Results:

• The developed interferometer-ellipsometer successfully determined the refractive index and thickness of polyethylene.
• Measurements were conducted in the far-infrared spectral range (15-35 cm⁻¹).
• The system demonstrated unambiguous determination of ellipsometric parameters without a retarder.

Conclusions:

• The novel polarizing interferometer-ellipsometer provides a simplified and accurate method for FIR characterization.
• The proposed design offers a robust solution for optical property determination in the far-infrared.
• The findings suggest potential applicability for mid-infrared spectral regions as well.