title: A novel unsplit perfectly matched layer for the second-order acoustic wave equation.
abstract: When solving acoustic field equations by using numerical approximation technique, absorbing boundary conditions (ABCs) are widely used to truncate the simulation to a finite space. The perfectly matched layer (PML) technique has exhibited excellent absorbing efficiency as an ABC for the acoustic wave equation formulated as a first-order system. However, as the PML was originally designed for the first-order equation system, it cannot be applied to the second-order equation system directly. In this article, we aim to extend the unsplit PML to the second-order equation system. We developed an efficient unsplit implementation of PML for the second-order acoustic wave equation based on an auxiliary-differential-equation (ADE) scheme. The proposed method can benefit to the use of PML in simulations based on second-order equations. Compared with the existing PMLs, it has simpler implementation and requires less extra storage. Numerical results from finite-difference time-domain models are provided to illustrate the validity of the approach.
authors.affiliation: National Key Laboratory of ASIC and System of Fudan University, Shanghai 200030, China; Department of Electronic Engineering, Fudan University, Shanghai 200433, China.
authors.forename: Youneng
authors.initials: Y
authors.lastname: Ma
authors.affiliation: National Key Laboratory of ASIC and System of Fudan University, Shanghai 200030, China; Department of Electronic Engineering, Fudan University, Shanghai 200433, China. Electronic address: jhyu@fudan.edu.cn.
authors.forename: Jinhua
authors.initials: J
authors.lastname: Yu
authors.affiliation: Department of Electronic Engineering, Fudan University, Shanghai 200433, China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Wang
keywords: Acoustic; Auxiliary-differential equation; Perfectly matched layer; Second-order equation