Remote photoacoustic imaging for material inspection

We report on (to our knowledge) the first remote contactless photoacoustic imaging with short excitation pulses on semitransparent solid polymer samples for material inspection. In this work solid semitransparent samples are excited with pulses from a short pulse laser. The local absorption of the electromagnetic radiation leads to generation of broadband ultrasonic waves. Ultrasonic waves arriving on the sample surface are detected with a confocal Fabry-Pérot interferometer. After data acquisition the absorbed energy density is reconstructed by utilizing an F-SAFT algorithm. The work shows the potential of photoacoustic imaging on material inspection of semitransparent solid materials.