The CFS-PML for Periodic Laguerre-Based FDTD Method

In this letter, the complex frequency shifted (CFS) perfectly matched layer (PML) is developed for the unconditionally stable finite-difference time-domain method based on weighted Laguerre polynomials for periodic structures. To verify the validity of the presented method, a numerical example of scattering from periodic structures is given. Numerical results show that, compared with the traditional PML, the CFS-PML is more effective in absorbing the evanescent waves, and has about 32 dB improvement in terms of the maximum relative error and much lower reflection error for the late-time.