Abstract Transparent optically anisotropic substrates (TOASs) are a crucial component in flexible electronics. Moreover, knowing the deflection radii of TOASs is essential to estimate the residual stresses of the thin films deposited on them. This paper proposes a novel measurement method to measure the deflection radii of polyimide (PI) substrates. Red, green, and blue filters and a circularly polarized system were used in the proposed method to investigate the influence of measurement precision on the wavelength of light adopted. Moreover, the image averaging technique was adopted to significantly reduce the noise in the fringe. Thus, the proposed method could be performed using only one set of image information and the measurement resolution could be improved to the sub-grayscale order. The experimental results reveal that red light can be adopted to precisely measure the deflection radii of PI substrates (error of 2.90%) However, large errors are caused when green light is used (22.35%). The experimental results reveal that blue light cannot be used to obtain any interferometric fringe patterns to calculate the deflection radius.

中文翻译：

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使用 RGB 滤光片和圆偏振系统以亚灰度分辨率测量光学各向异性聚合物基板的偏转半径

摘要 透明光学各向异性基板 (TOAS) 是柔性电子产品的重要组成部分。此外，了解 TOAS 的偏转半径对于估计沉积在其上的薄膜的残余应力至关重要。本文提出了一种新的测量方法来测量聚酰亚胺 (PI) 基板的偏转半径。所提出的方法中使用红、绿、蓝滤光片和圆偏振系统来研究测量精度对所采用光波长的影响。此外，采用图像平均技术显着降低了条纹中的噪声。因此，所提出的方法可以仅使用一组图像信息来执行，并且可以将测量分辨率提高到亚灰度级。实验结果表明，可以采用红光来精确测量PI基板的偏转半径（误差为2.90%），而使用绿光时误差较大（22.35%）。实验结果表明，蓝光不能用于获得任何干涉条纹图案来计算偏转半径。