Polarization-sensitive spectroradiometer: two methods for overcoming the problems of measuring reflectance spectra

Area of Science:

• Optical physics
• Spectroscopy
• Metrology

Background:

• Spectroradiometers are crucial for measuring light intensity.
• Polarization of incident or transmitted light can cause significant errors in spectral measurements.
• Accurate reflectance spectra are vital for material characterization and optical system design.

Purpose of the Study:

• To identify the sources of error in spectroradiometer measurements due to polarization.
• To propose and validate methods for obtaining accurate power reflectance spectra in the presence of polarization.
• To ensure the reliability of spectral data for scientific and industrial applications.

Main Methods:

• Developing two distinct methodologies to correct for polarization-induced errors.
• Method 1: Averaging reflectance spectra acquired at orthogonal rotation angles of the spectroradiometer.
• Method 2: Averaging reflectance spectra of orthogonal polarized light components, with specific orientation for the incoming light.

Main Results:

• Demonstrated that averaging spectra from orthogonal rotation angles corrects for polarization effects.
• Showcased that averaging orthogonal polarized components also yields correct reflectance spectra.
• Confirmed that the second method can simultaneously determine the degree of polarization.

Conclusions:

• Accurate power reflectance spectra can be obtained from spectroradiometers even with polarized light.
• The proposed averaging techniques effectively mitigate polarization-induced errors.
• These methods enhance the reliability and accuracy of spectroradiometric measurements.