US 12,146,861 B2
Photo-acoustic tomography defect testing system and method
Francis L. Leard, Sudbury, MA (US); James A. DeMuth, Woburn, MA (US); and Andrew J. Bayramian, Marblehead, MA (US)
Assigned to Seurat Technologies, Inc., Wilmington, MA (US)
Filed by Seurat Technologies, Inc., Mountain View, CA (US)
Filed on Jun. 9, 2021, as Appl. No. 17/343,109.
Claims priority of provisional application 63/036,885, filed on Jun. 9, 2020.
Prior Publication US 2021/0382013 A1, Dec. 9, 2021
Int. Cl. G01N 29/24 (2006.01); G01B 9/02 (2022.01); G01B 11/30 (2006.01); G01N 29/04 (2006.01); G01N 21/17 (2006.01)
CPC G01N 29/2418 (2013.01) [G01B 9/02041 (2013.01); G01B 11/303 (2013.01); G01N 29/04 (2013.01); G01N 2021/1706 (2013.01); G01N 2291/023 (2013.01); G01N 2291/0289 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A method comprising:
generating a hammer beam using laser light having a first wavelength;
generating a read-out beam using laser light having a second wavelength;
directing the generated hammer beam toward a first position on one or more additive layers of a part to provide an acoustic hammer pulse that induces surface movement of the part, wherein the one or more additive layers of the part are printed using a laser print system according to one or more printing parameters;
reading the surface movement of the part using the read-out beam directed to a second position on the one or more additive layers of the part and an areal camera arranged to produce an interferogram image comprising pixels that correspond to positions of a layer of the part; and
adjusting the one or more printing parameters for printing at least one additional layer of the part using the laser print system according to pixels of the interferogram image.