D. Yevick et al., OPTIMAL ABSORBING BOUNDARY-CONDITIONS, Journal of the Optical Society of America. A, Optics, image science,and vision., 12(1), 1995, pp. 107-110
We examine three simply implemented boundary conditions for finite-dif
ference electric field propagation. We find that although so-called tr
ansparent boundary conditions are appropriate for highly collimated be
ams, properly tailored absorbers are generally better adapted to reali
stic field distributions. Our analysis incorporates a simple procedure
for constructing nearly optimal absorber functions as well as a novel
mixed transparent/absorbing boundary condition.