LED-based Schlieren System for Full-field Photoacoustic Wave Acquisition and Image Reconstruction

In this work, the full-field detection of laser-induced ultrasound waves is performed with an off-axis LED-based Schlieren system. Sensing strobe light, pulsed laser dual light-sheet excitation, and CMOS sensor device are all synchronized to capture the pressure wave as it propagates through an elastic liquid surrounding the test sample. In addition, a reconstruction algorithm based on the Radon transform was applied to the digitally recorded field in order to obtain an image of the photoacoustic source. The proposed system is capable to retrieve the profile of cylindrical and hexagonal targets.