High Bandwith Laser Heterodyne Interferometer To Measure Transient Mechanical Displacements

As part of the research in optical techniques for non-destructive evaluation (NDE), we have considered the reception of elastic waves with no contact via a heterodyne detection wideband laser interferometer. The purpose of this article is to present the performances of the model. We have included the operating principles of laser interferometry, the reasons for the technological choices made, the electronic reception system and signal demodulation. The performances of the transient microdisplacement measurement are depicted with few experiments in the field of NDE.