In this paper a new method for the detection of optical phase in passive homodyne interferometers, with high accuracy and wide dynamic range is presented. Unlike the traditional and more recent methods, which use between 3 and 6 harmonic components to calculate the modulation index, the proposed method uses only 2 harmonic components. Because of this, the method has higher accuracy in the presence of noise compared to other methods known in the literature. Further, the method has the advantage of not requiring knowledge of the phase of the excitation signal. The numerical implementation is simple, since it uses a 3rd order polynomial fit for the calculation of the modulation index. For the experimental verification of the method, a configuration based on an unbalanced Mach-Zehnder interferometer (MZI) was used, which resulted in a dynamic range for the modulation index from 8.38 to 16.76 rad. It is important to note that these limits can be easily expanded by means of adaptations of the optical and electronic setup depending on the characteristics of the excitation signal. The proposed method can be used in several applications, such as pressure measurements, vibration, displacement, etc.

中文翻译：

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用于宽动态范围应用的高精度零差干涉测量方法

本文提出了一种高精度、宽动态范围的无源零差干涉仪光学相位检测新方法。与使用 3 到 6 个谐波分量来计算调制指数的传统方法和最近的方法不同，所提出的方法仅使用 2 个谐波分量。因此，与文献中已知的其他方法相比，该方法在存在噪声的情况下具有更高的准确度。此外，该方法具有不需要知道激励信号的相位的优点。数值实现很简单，因为它使用三阶多项式拟合来计算调制指数。对于该方法的实验验证，使用了基于不平衡马赫-曾德干涉仪 (MZI) 的配置，这导致调制指数的动态范围从 8.38 到 16.76 rad。重要的是要注意，这些限制可以通过根据激发信号的特性调整光学和电子设置来轻松扩展。所提出的方法可用于多种应用，例如压力测量、振动、位移等。