Self-mixing interference signal analysis based on Lissajous figure convergence algorithm for vibration measurement

Abstract

To preserve the inherent simplicity of the optical path and ensure a streamlined signal processing workflow while attaining high-precision measurement results, we propose an algorithm for vibration measurement in a self-mixing system based on the convergence of Lissajous figures in the weak and very weak feedback regimes. In this algorithm, a series of estimated self-mixing signals are generated to make Lissajous figures with the test self-mixing signal, and the degree of convergence of Lissajous figures, judged by the Euclidean distance of the intersections, is used as the criterion for determining the optimal target vibration amplitude. The effectiveness of this algorithm was proved through both simulations and experiments, yielding a measurement error not exceeding 10 nm.