Tuning the characteristics of photoacoustic pressure in a laser-induced photoacoustic generator: A numerical study

Abstract

We present a new numerical approach to model a laser-induced photoacoustic generator (LIPAG) by integrating thermal, elastic, and acoustic multiphysics simulations in a linear regime. Our unique approach implements a fully-explicit staggered-grid finite-difference time-domain method with perfectly matched layers to remove common artifacts in numerical simulations due to finite-sized computational domains. The approach simulates the dynamics of photoacoustic (PA) pressure signals and local temperature fields using realistic LIPAG models to elucidate details of the underlying PA pressure generation mechanism. We also report on how the pressure wave characteristics are affected by the variation of the key parameters of the pulsed light and material properties. Our simulation technique, capable of adjusting a wide range of key parameters in the LIPAG model, may provide a guidance in the design of LIPAGs to achieve desired PA pressure characteristics for testing the performance of acoustic transducers and their calibrations.