  The Photonic hybRid EleCtromagnetic SolvEr (PRECISE) is a Matlab based
library to model large and complex photonics integrated circuits. Each circuit
is modularly described in terms of waveguide segments connected through
multiport nodes. Linear, nonlinear, and dynamical phenomena are simulated by
solving the system of differential equations describing the effect to be
considered. By exploiting the steady state approximation of the electromagnetic
field within each node device, the library can handle large and complex
circuits even on desktop PC. We show that the steady state assumption is
fulfilled in a broad number of applications and we compare its accuracy with
analytical model (coupled mode theory) and experimental results. PRECISE is
highly modular and easily extensible to handle equations different from those
already implemented and is, thus, a flexible tool to model the increasingly
complex photonic circuits.
