Currently, I am working on a validation of a nonlinear directional coupler. I am trying to validate figure 2 in the attached paper.To validate this structure, I modified the directional coupler example at the lumerical website at this link: (https://kb.lumerical.com/en/pic_passive_waveguide_couplers_evanescent.html) to the structure mentioned in the paper but I have a problem with modeling the nonlinear-kerr material as the results seems to be not affected by the changes made to the chi3 parameter. Also, I doobayya2000.pdf (167.1 KB)n’t know how to change the power of the input beam.
Since the FDE solver in MODE Solutions is a frequency domain solver, unfortunately it’s not possible to model nonlinear effects, so any of the materials which are implemented using material plugins (listed here: https://kb.lumerical.com/en/index.html?materials_advanced_material_models.html) should not be used with the FDE solver.
I would recommend instead using the 2.5D varFDTD solver. Since it performs time-domain simulations, it can take into account nonlinear materials. You could set the power of the input beam by editing the source in the varFDTD simulation. I would definitely recommend taking a look at the following video which talks about how to simulate nonlinear waveguide systems: