Vibration measurement based on Multiple Self-Mixing Interferometry

We propose a novel algorithm for Multiple Self-Mixing Interferometry (MSMI). The algorithm is able to measure nanometer scale vibration by the power spectrum analysis. In the paper, the principles of the method are introduced in detail. The experimental setup has been built. The validity of the proposed algorithm was confirmed by conducting a series of experimental measurements at different reflection times, feedback factors, and vibrational frequencies using PZT as a reference. Experimental results showed that the method can quickly demodulate parameters of vibration and good correspondence between theory and experiment. The proposed algorithm, thus, furnishes nanometer measurements with a very high resolution using a self-aligned, cost effective and compact experimental setup.