Guilin Sun
Ansys Employee

For details of source implementation you can refer a FDTD book, or Shineider's online book.

where did you get the simulated result? from source its self or from a monitor? where the monitor is located? I did not find more information how did you import and how did you measure it.

 

I tested a plane wave import without noticing any additional phase from the source.

simply modify this examle https://optics.ansys.com/hc/en-us/articles/360034383054-Using-an-equation-to-define-the-spatial-field-profile-of-a-source-in-FDTD

Ex=envelope/envelope;

Ey=Ex*0;

Ez=Ex*0;

and set the xy boundary conditions as periodic. Please test your own and compare with your original simulation.