Multi-Physics Utility Product Overview

The Multi-Physics Utility™[1] is designed to be used in conjunction with any of RSoft's passive device simulation tools. It provides a convenient interface from which perturbations of the refractive index profile of a structure may be included in the simulation. These perturbations can be caused by advanced physical processes in the material, such as electro-optic effects, thermo-optic effects, stress-optic effects (i.e., strain), and carrier-induced effects. All material parameters needed to describe these effects can be defined in RSoft's Material Library.

[1] The basic Multi-Physics Utility with electro-optic and thermo-optic effects is included with all passive device tools; the stress and carrier effects are offered as options that are licensed separately.

Change in refractive index

Change in refractive index, due to carrier effects, in a silicon ridge waveguide buried in SiO2

X component of strain

X component of strain in a silicon ridge waveguide buried in SiO2


  • Expands the power of all of RSoft's passive device simulation tools.
  • Fully integrated into the RSoft CAD Environment.


  • Electro-absoptive/electro-refractive modulators
  • Thermo-optic switches
  • Electrically biased modulators
  • Birefringence in waveguides and fibers
  • Stress effects caused by cooling during device fabrication


  • Fully integrated with all of RSoft's passive device simulation tools.
  • Leverages RSoft's material library for all model parameters.
  • Computes index perturbation by solving Poisson's equation (electro-optic effect), thermal equation (thermo-optic effect), stress-strain equation (stress effect), and by using LaserMOD to model carrier-based effects.
  • Automated parametric studies and design optimization using MOST

Application Gallery