Learning Forum

[Jordi Lopez Leyva]

I'm simulating a Photonic crystal in FDTD, where light should form a pattern similar to a grating (show in figure). I import a calculated optical generation into CHARGE. However, when I try simulate the carrier generation in CHARGE, I don't see the grating formation. Instead, carriers seem to be smoohted across the entire material instead of forming a grating. How can I ensure a grating is formed in CHARGE?

My simulation is with GaAs transient isothermal, 1000fs max steps (200ps steps) for 10ps simulation time with electrical boundary condition transient. Optical generation is on for only 100fs. I removed all recombination from the GaAs electrical material.

Optical generation:

 

initial E field:

 

initial carrier generation (bottom is clipped through the middle, the top one is the volume plot showing the surface):

 

[Jordi Lopez Leyva]

I figured out the issue was the mesh order. I copied my structure from FDTD, but mesh orders in FDTD depend also on refractive index. But in CHARGE this needs to be set manually.