Transmission-Line Modeling of Materials

The Transmission-Line Modeling (TLM) method formulated for unstructured triangular grids is extended to model materials exhibiting instantaneous dielectric nonlinearity. This has applications in modeling various optical devices—e.g. switches, limiters, and all-optical photonic circuits—whose operation is based upon the nonlinear material properties. The time-domain formulation of TLM makes it an effective method for modeling nonlinear phenomena. In addition, unstructured meshes facilitate the accurate description of oblique or curved material interfaces and allow mesh grading to be applied around fine-features and complex structures.