EMD filter algorithm for self-mixing interference displacement sensor

Considering the issue of noise reduction associated with self-mixing interference (SMI), the paper presented an empirical mode decomposition (EMD) filter algorithm for SMI laser sensor that enables more accurate reconstruction of the displacement information from an SMI signal. The performance of the algorithm is studied. It is shown that the algorithm are capable of removing white noise and high frequency noise and so on. The phase unwrapping displacement reconstructions method based on this algorithm have been experimentally validated, with laser subject to the weak and moderate feedback regime, strong feedback regime. The experimental results shown that the method could reduce reconstruction error in simulations and experiments.