Guilin Sun
Ansys Employee
When you change to ultra short pulse, do you know if the spectrum changes or not? FDTD mesh depends on the smallest wavelength inside the material. For simple dispersive material, it depends on min(wavelength/real(n)). So if the starting wavelength changes, the mesh is different, and thus the result may be different. In addition, if source changes, the material fitting will be changed. You can fix the meshing and material fitting. Please refer this post: Ansys Insight: 光谱宽度会影响同波长的透过率吗?分段仿真如何得到光滑的结果 One important question: is there any specific reason you want to use ultra-short pulse? are you simulating nonlinear material? if not, except some special cases, I would recommend to use standard source pulse.