NUMERICAL SIMULATION OF FIBER-OPTIC PHOTOACOUSTIC GENERATOR USING NANOCOMPOSITE MATERIAL.

Photoacoustic generation using an optical fiber is a promising approach to meet the challenges in most advanced ultrasonic non-destructive testing (NDT) applications. The energy-absorption layer coated on the fiber, endface plays an important role in converting the laser energy into heat and exciting the acoustic wave. The selection of the absorption material and the optimization of the structure dimension are the keys for achieving high energy-conversion efficiency. A 2D-axisymmetric finite element analysis (FEA) model was established to simulate the photoacoustic generation process using a newly developed absorption material, polydimethylsiloxane/gold nanoparticle (PDMS/Au NPs) nanocomposites, with different thicknesses and laser pulse durations. The experimental results obtained using a similar set-up show a similar trend predicted by this FEA simulation. The FEA results provide practical clues to the design of the fiber-optic photoacoustic generator. [ABSTRACT FROM AUTHOR]