ABSTRACT
There is a large literature describing models of ultrasound propagation in biological soft tissue, much of which is directly applicable to photoacoustics, and there are numerous approaches to solving partial differential equations numerically. When modeling photoacoustic waves in biological tissue, it is usual to make a number of assumptions in order to simplify the model's formulation. This chapter shows that k-space methods provide a natural, efficient, and straightforward approach to modeling photoacoustic wave propagation. It explains the k-space models, each with different strengths and weaknesses, but all considerably more efficient than finite element (FE) or finite difference (FD) methods of equivalent accuracy. K-space models are particularly appropriate to pulsed photoacoustics due to the nature of the source; indeed, the initial value problem that arises under conditions of stress confinement can be solved exactly using just two fast Fourier transforms (FFTs).
