Processing the quadrature signals of an interferometer using an Arduino microcontroller

• Date: 2025
• Main Authors: Бородін, Ю. О., Олейнік, Д. Е., Цубін, О. А., Пригун, О. В., Лапчук, А. С., Брицький, О.І.
• Format: Article
• Language: Ukrainian
• Published: Інститут проблем реєстрації інформації НАН України 2025
• Subjects: sub-nanometer displacements; homodyne quadrature laser interferometer; Arduino microcontroller; analog-to-digital processing; CORDIC algorithm
• Online Access: https://drsp.ipri.kiev.ua/article/view/354599
• Journal Title: Data Recording, Storage & Processing

The wide application of interferometers in various spheres of human activity makes its serial production, reduction of dimensions and reduction of cost of manufacturing of interferometers relevant. One of the simplest implementations of accurate displacement measurement is based on the Michelson quadrature laser interferometer. Calculation of displacement by conventional methods requires significant computation power that can be implemented only on large microcircuits. One of the methods of reducing the cost and size of this class of devices is implementation of simple and effective optical signal processing methods that would allow the use of simple microcontrollers to calculate the displacement from the optical signal of the interferometer. A simple and extremely effective method for calculating displacement based on the CORDIC algorithm has been developed, which is implemented in the form of a program for a simple and cheap Arduino chip for signal processing using the example of a horizontal seismometer of the SL-220 type. Experimental studies of the effectiveness and accuracy of the method have been carried out, as well as its comparison with other more complex methods that require more powerful computing devices, in particular the processing method using LabView software implemented on a separate analog-to-digital converter. Experimental results have shown that the system on the Arduino microcontroller using the CORDIC algorithm does not lose in the accuracy of displacement measurement, and has a significant advantage at higher displacement frequencies over method using direct complex algorithm displacement evaluation using more complex and expensive microcircuits, such as the system based on NI USB 6212 + LabView and ADC AD7656 + Raspberry Pi 3. Tabl.: 1. Fig.: 10. Refs: 32 titles.