Based on the nature of self-mixing signals, we propose the use of the multiple signal classification (MUSIC) algorithm in place of the fast Fourier transform (FFT) for processing signals obtained from self-mixing interferometry (SMI). We apply this algorithm to two representative SMI measurement techniques: range finding and velocimetry. Applying MUSIC to SMI range finding, we find its signal-to-noise ratio performance to be significantly better than that of the FFT, allowing for more robust, longer-range measurement systems. We further demonstrate that MUSIC enables a fundamental change in how SMI Doppler velocity measurement is approached, letting one discard the complex fitting procedure and allowing for a real-time frequency estimation process.
© 2013 Optical Society of America
Remote Sensing and Sensors
Original Manuscript: November 21, 2012
Manuscript Accepted: March 29, 2013
Published: May 7, 2013
Milan Nikolić, Dejan P. Jovanović, Yah Leng Lim, Karl Bertling, Thomas Taimre, and Aleksandar D. Rakić, "Approach to frequency estimation in self-mixing interferometry: multiple signal classification," Appl. Opt. 52, 3345-3350 (2013)