The thickness variation of transparent optical flats has become a crucial parameter owing to the development of display and semiconductor technologies. Systematic offset phase errors can be generated when the absolute thickness of samples is profiled using a Fizeau interferometer. In this study, a novel 11-sample phase extraction formula was developed to suppress offset phase errors during thickness measurements. The newly developed 11-sample formula was visualized on the frequency domain and complex plane by using Fourier description and the algorithmic polynomial theory. The offset error compensation capability of the 11-sample formula was confirmed based on the results of a numerical analysis. Finally, the glass thickness was measured using a wavelength-scanning Fizeau interferometer and the proposed 11-sample formula. The standard deviation was 9.654 nm, which demonstrates the superior capability of this formula.

由于显示器和半导体技术的发展，透明光学平板的厚度变化已成为关键参数。当使用Fizeau干涉仪测量样品的绝对厚度时，会产生系统性的偏移相位误差。在这项研究中，开发了一种新颖的11样本相提取公式，以抑制厚度测量过程中的偏移相位误差。通过使用傅立叶描述和算法多项式理论，可以在频域和复杂平面上可视化新开发的11个样本公式。根据数值分析结果，确定了11个样本公式的偏移误差补偿能力。最后，使用波长扫描Fizeau干涉仪和建议的11样品公式测量玻璃厚度。