Polarized light, the integrating sphere, and target calibration

Area of Science:

• Optical physics
• Metrology

Background:

• Calibration of diffuse targets is crucial for accurate optical measurements.
• Nonideal targets and polarized light introduce complexities not addressed by scalar theory.

Purpose of the Study:

• To discuss the calibration of nonideal diffuse targets irradiated by polarized light.
• To highlight the limitations of traditional calibration methods.

Main Methods:

• Analysis of conical-hemispherical (or directional-hemispherical) and bihemispherical reflectance measurements.
• Consideration of non-depolarizing targets and integrating sphere walls.

Main Results:

• Standard comparison techniques based on scalar theory are inadequate for these targets.
• Mueller reflectance matrix is required when sphere walls do not depolarize light.

Conclusions:

• Accurate calibration of nonideal diffuse targets requires advanced optical characterization beyond scalar methods.
• The use of Mueller matrices is essential for precise reflectance determination in complex optical systems.