https://doi.org/10.1051/epjconf/202328709017
Phase Modulated Frequency Shifted Digital Holographic Vibrometry with Enhanced Robustness
1 Technische Universität Ilmenau, Institute of Micro- and Nanotechnologies, Optical Engineering Group, 98693 Ilmenau, Germany
2 Coburg University of Applied Sciences and Arts, ISAT - Institute of Sensor and Actuator Technology, 96450 Coburg, Germany
* Corresponding author: florian.doetzer@tu-ilmenau.de
Published online: 18 October 2023
We report experimental results of a frequency shifted digital holography setup for spatially resolved vibrometry. A spatially homogeneous artificial phase modulation is used as a reference to correct for speckle noise. Furthermore, when superimposed upon the object vibration with slightly different frequency, the resulting beat can be evaluated. The beat frequency is invariant under relative motion between the object and interferometer, providing robustness in presence of parasitic low-frequency vibrations. In addition, the ’working point’ is raised out of the noise floor, providing the opportunity to enhance the sensitivity at small vibration displacements. The method is demonstrated by measurements on a vibrating clarinet reed.
© The Authors, published by EDP Sciences, 2023
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
