MODELING OF NONLINEAR-OPTICAL MEDIA WITH THE TLM-BASED FINITE-DIFFERENCE - TIME-DOMAIN METHOD

A transmission-line-matrix (TLM) node equivalent, the TLM-based finite -difference-time-domain (FDTD) method, has been recently proposed to a llow the simulation of electromagnetic fields in a FDTD fashion. As a result, modeling and simulation techniques developed for the conventio nal FDTD scheme can be directly implemented into the TLM-based algorit hm. In this article the nonlinear modeling scheme accomplished with a Z transform is adapted and implemented in the proposed TLM-based FDTD method, to simulate the electromagnetic behaviors in optical media wit h nonlinear polarization, such as Kerr and Raman effects. Numerical re sults are presented for one-dimensional calculation of propagation of femtosecond electromagnetic solitons that retain the optical carriers. The results are in good agreement with those obtained from the conven tional FDTD simulation. In conclusion, the TLM-based FDTD method is fo und to be robust and flexible in 2D and 3D modeling. (C) 1996 John Wil ey & Sons, Inc.