A MICRO-DISPLACEMENT MEASUREMENT SYSTEM BASED ON POLARIZERS

To address the insufficient accuracy and complex optical alignment of the traditional optical lever method in micrometer-scale displacement measurement, this study proposes a non-contact high-precision measurement method based on polarizers. In this method, micro-displacements are generated using a Young's modulus apparatus and converted into changes in polarization angle through a self-designed angle-conversion device based on an optical lever. According to Malus's law, a highly stable light source with an intensity of 50000.0lx and a fluctuation of less than 0.4%, together with high-degree-of-linear-polarization polarizers with DOLP (Degree of Linear Polarization) greater than 99.988%, is used to convert the polarization-angle variation into an optical-intensity signal. The DBSCAN algorithm is applied for denoising, and a linear light-intensity correction model is used to optimize the data, thereby significantly improving measurement reliability. Experimental results show that, within the measurement range of 0.217~1419μm, the relative error of this method is less than 1.2%, and the uncertainty is better than 0.62μm, demonstrating significantly better performance than the traditional optical lever method. This system combines high precision, high stability, and low cost, and provides an efficient and reliable solution for teaching demonstrations and industrial micro-displacement detection.