Stray-light corrections in integrating-sphere measurements on low-scattering samples

Area of Science:

• Optical Metrology
• Photometry
• Spectroscopy

Background:

• Integrating spheres are crucial for optical measurements.
• Stray light from imperfect components introduces significant errors.
• Accurate characterization of low scattering (<1%) is challenging.

Purpose of the Study:

• To extend integrating sphere correction methods to include stray light errors.
• To enable precise measurement of low scattering levels.
• To develop a practical procedure for stray light determination.

Main Methods:

• Extended existing integrating sphere correction methods.
• Incorporated stray light contributions from optical imperfections.
• Developed a procedure for experimental determination of stray light components.

Main Results:

• Demonstrated accurate measurement of scattering below 1% using a standard integrating sphere.
• Showed that stray light corrections are critical for low-scattering samples.
• Presented simple equations for calculating diffuse and specular reflectance and transmittance.

Conclusions:

• The extended method accurately corrects for stray light in integrating sphere measurements.
• Precise characterization of low-scattering optical components is achievable.
• The presented equations simplify data analysis for reflectance and transmittance.