An FDTD formulation for dispersive media using a current density

A novel finite-difference time-domain (FDTD) formulation for dispersive media called the JE convolution (JEC) method is derived using the convolution relationship between the current density J and the electric field E. The high accuracy of the JEC method is confirmed by computing the reflection and transmission coefficients for a nonmagnetized plasma slab in one dimension. It is found that the new method has an accuracy comparable to the auxiliary differential equation (ADE) while having the same computational efficiency as the less accurate recursive convolution (RC) method. Numerical simulations also show that the JEC method exhibits significantly higher accuracy than the RC method in modeling wave attenuation inside the plasma.