Full matrix capture and the total focusing imaging algorithm using laser induced ultrasonic phased arrays

Theodosia Stratoudaki, Matt Clark, Paul D. Wilcox

Research output: Chapter in Book/Report/Conference proceedingConference contribution book

2 Citations (Scopus)
245 Downloads (Pure)


Laser ultrasonics is a technique where lasers are used for the generation and detection of ultrasound instead of conventional piezoelectric transducers. The technique is broadband, non-contact, and couplant free, suitable for large stand-off distances, inspection of components of complex geometries and hazardous environments. In this paper, array imaging is presented by obtaining the full matrix of all possible laser generation, laser detection combinations in the array (Full Matrix Capture), at the nondestructive, thermoelastic regime. An advanced imaging technique developed for conventional ultrasonic transducers, the Total Focusing Method (TFM), is adapted for laser ultrasonics and then applied to the captured data, focusing at each point of the reconstruction area. In this way, the beamforming and steering of the ultrasound is done during the post processing. A 1-D laser induced ultrasonic phased array is synthesized with significantly improved spatial resolution and defect detectability. In this study, shear waves are used for the imaging, since they are more efficiently produced than longitudinal waves in the nondestructive, thermoelastic regime. Experimental results are presented from nondestructive, laser ultrasonic inspection of aluminum samples with side drilled holes and slots at depths varying between 5 and 20mm from the surface.

Original languageEnglish
Title of host publication43rd Annual Review of Progress in Quantitative Nondestructive Evaluation, Volume 36
EditorsDale E. Chimenti, Leonard J. Bond
Place of PublicationMelville, NY
Number of pages9
Publication statusPublished - 16 Feb 2017
Event43rd Annual Review of Progress in Quantitative Nondestructive Evaluation, QNDE 2016 - Atlanta, United States
Duration: 17 Jul 201622 Jul 2016


Conference43rd Annual Review of Progress in Quantitative Nondestructive Evaluation, QNDE 2016
Country/TerritoryUnited States


  • laser ultrasonics
  • non-contact
  • array imaging
  • full marix capture
  • thermoelastic regime
  • total focusing method
  • shear waves

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