POEMS: Programmable Optimizing Electromagnetic Simulator

Tue, 10 Dec 2019 02:08:39 +0000

There are a variety of EM simulation schemes in wide use, with different strengths and weaknesses. For free-space antennas at radio frequency, where dielectrics are simple and metals are excellent conductors, integral equation schemes such as the method of moments (MoM) win. At optical frequencies, particularly when metal is involved, partial differential equation methods are generally better. The two most common PDE schemes are finite element method (FEM) and finite difference, time domain (FDTD). The antenna-coupled tunnel junction work required simulations with very fine resolution (1 nm) in some places, to represent plasmons and metal surface discontinuities, and a very large simulation domain, at least 5 μm square by 20 μm long. This requires multiprocessor capability and subgridding, i.e. different places in the simulation domain having different cell sizes. Subgridding is a natural strength of FE, but presents a challenge in FDTD, which naturally likes uniform cubical grids. On the other hand, mesh generation can be very time consuming, and FEM doesn’t clusterize as well as FDTD and is much harder to get correct.

Simulators on ElectroOptical Innovations

POEMS: Programmable Optimizing Electromagnetic Simulator