Abstract
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Approaches that are, to our knowledge, novel, are proposed in this paper to improve the accuracy performance
of self-mixing interferometry (SMI) for displacement measurement. First, the characteristics
associated with signals observed in SMI systems are studied, based on which a new procedure is proposed
for achieving accurate estimation of the laser phase. The studies also revealed the reasons for the inherent
errors associated with the existing SMI-based techniques for displacement measurement. Then,
this paper presents a new method for estimating the optical feedback level factor (denoted by C) in real
time. Combining the new algorithms for estimating the laser phase and updating C value, the paper
finally presents a novel technique for displacement measurement with improved accuracy performance
in contrast to existing techniques. The proposed technique is verified by both simulation and experimental data.