Work

Accurate polarization characterization of thin film polarizing beamsplitters with cavity ring-down technique

Year: 2025

Type: article

Abstract: The cavity ring-down (CRD) technique is employed to accurately measure the polarization characteristics of thin film polarizing beamsplitters (PBSs). The measurement principle and related theory are provided. By establishing s- and p- polarized two-channel CRD configurations, the s- and p-polarization transmittance and reflectance values ( T s , T p , R s , and R p ) and the polarization extinction ratio ( PER ?=? T p / T s ) of the thin film PBSs are measured with high accuracy. The experimental results with a 45-degree and a Brewster angle PBS demonstrate that the two-channel CRD is capable of measuring the p -polarization transmittance T p of ?99.0% and higher with an error of 0.01?0.02% or lower, and the s -polarization transmittance T s ?<?1 ppm with an uncertainty of?<?0.01 ppm or ???1.0%. A PER as high as 10 6 :1 is determined by CRD with an error of only 1.0?2.0%. Comparisons between PER measurements using CRD and spectrophotometry show that that CRD offers much higher accuracy for high PER measurements than spectrophotometry. The two-channel CRD is expected to measure the PER of thin film PBSs with an uncertainty of ?1.0% across the entire range from approximately 100:1 to >10 9 :1.

Source: Optics Express

DOI: 10.1364/oe.563725

Authors: Yanling Han, Bincheng Li, Jing Wang, Hao Cui, Xiaoxiao Chen

Institutions: Chinese Academy of Sciences, Institute of Optics and Electronics, Chinese Academy of Sciences, National Institute of Measurement and Testing Technology

Language: English

Topic: Optical Polarization and Ellipsometry

Subfield: Biomedical Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,270

Funder: National Key Research and Development Program of China