Quantitative discrimination of pearls using polarization-sensitive optical coherence tomography

Area of Science:

• Optical physics
• Materials science
• Gemology

Background:

• Distinguishing genuine pearls from imitations is challenging.
• Polarization-sensitive optical coherence tomography (PS-OCT) can qualitatively assess pearl birefringence.
• A quantitative method is needed for reliable pearl evaluation.

Purpose of the Study:

• To introduce a quantitative method for discriminating genuine from imitation pearls.
• To apply the concept of entropy to PS-OCT data for pearl analysis.
• To establish phase retardation entropy as a criterion for pearl evaluation.

Main Methods:

• Utilizing polarization-sensitive optical coherence tomography (PS-OCT).
• Introducing and calculating phase retardation entropy from PS-OCT tomograms.
• Analyzing the birefringence properties of the nacreous layer in pearls.

Main Results:

• Genuine pearls exhibited higher phase retardation entropy values compared to imitation pearls.
• PS-OCT allowed for qualitative discrimination based on birefringence.
• Phase retardation entropy provided a quantitative measure of birefringence diversity.

Conclusions:

• Phase retardation entropy is an effective quantitative criterion for distinguishing genuine from imitation pearls.
• The proposed method offers a robust approach for pearl authentication.
• This technique enhances the evaluation of pearl authenticity and quality.