Memory efficient Laguerre-FDTD scheme for dispersive media

The unconditionally stable Laguerre-FDTD method is suitable for simulating 3-D structures with large time step. In this work, memory efficient Laguerre-FDTD scheme for dispersive materials is proposed to ensure accurate modeling and less memory consumption compared to standard procedures. The memory efficient scheme is realized by representing the Laguerre domain expression of electric susceptibility in a recursive manner. Formulations have been derived for both Debye and Lorentz media. Numerical results show that the proposed Laguerre-FDTD method exhibits significant peak memory usage reduction and equivalent calculation accuracy of dispersive material involved transient simulation.