Development of a variable and broad speed range all-fiber laser vibration measurement technology

This paper realizes a variable and broad speed range all-fiber heterodyne laser vibration measurement system. The system employs a dual-parallel Mach-Zehnder modulator to generate a carrier-suppressed single-sideband signal and facilitates non-contact vibration measurements based on the optical Doppler shift principle. The maximum speed can be measured is much higher than the general vibrometer. This technology has the advantages of high precision, dynamically adjustable measuring range, full-frequency modulation etc. In this paper, a prototype has been built, and Hilbert Transform is used to extract the vibration signal from the frequency shift signal. Laboratory experiment result shows the ability of mutative and expansive measuring range.