Recent developments in QCRF-FDTD modeling of complex dispersive media

We discuss recent developments in a finite-difference time domain (FDTD) algorithm for electromagnetic wave interaction with complex dispersive media, based on a quadratic complex rational function (QCRF). The QCRF is simple and accurate to consider frequency dispersive responses. Compared to the Debye, Drude, or Lorentz dispersion equation, the QCRF equation has more degrees of freedom and it is straightforward to implement update equations for QCRF-FDTD. We also discuss efficient memory storage of QCRF-FDTD by using a state-space approach.