Simultaneous measurement of depth-resolved refractive index field and deformation field inside polymers during the curing process. (December 2022)

• Record Type: Journal Article
• Authors: Huang, Pinbo; Lin, Yuankun; Bai, Yulei; Ni, Zihao; Xie, Shengli; Dong, Bo
• Is Part Of: Measurement. Volume 205(2023)
• Publication Date: 2022-12
• Subjects: Cure monitoring -- Light-cured resin -- Optical coherence tomography -- Phase sensitivity; Weights and measures -- Periodicals; Measurement -- Periodicals; Measurement; Weights and measures; Periodicals; 530.8
• DOI: 10.1016/j.measurement.2022.112184
• Languages: English
• ISSNs: 0263-2241

Abstract

Highlights: A refractive index model is proposed to extract displacement from OPD of PhS-OCT. The refractive index field changes with the curing process. Only the displacements like the refractive index change characterizes polymerization. Abstract: A method based on phase-sensitive optical coherence tomography (PhS-OCT) has recently been used to visualize curing process inside polymers [ Appl. Phys. Lett. 116: 054103 (2020)]. Based on this proven method, we further proposed a refractive index model to determine curing induced displacements. For validation, the curing process of a light-cured resin droplet was first monitored by recording a time series of spectral images. Amplitude images and phase difference maps were then calculated from the spectral images. Finally, according to the proposed refractive index model, amplitude and phase information were used together to simultaneously measure refractive index fields and displacement fields. The results show that the time-dependent refractive index field is generalized by a piecewise function consistent with the polymerization kinetics; only the displacements with the piecewise functional feature, similar to the refractive index change, can characterize polymerization shrinkage.