Figure 4
Absorptance versus frequency calculated by this approach and FMM with ABC for \(h=w_g/2000\)20; the incident angle is 60°; the number of truncated order is denoted as N. The curves in blue and yellow colours correspond to the results obtained by FMM with ABC of \(N=35\) and \(N=100\), respectively. The red and purple colours are for the cases of \(N=35\) and \(N=100\) based on our approach FMM incorporating LBFs.
