COMSOL'ers:
When performing 2-D full-field simulations of an opaque periodic structure at off-normal incidence, my results (near- and far-field profiles) vary as a function of the height of the upper (air) region. At normal incidence, however, there is good agreement.I know this topic has been addressed, but I have accounted for the solutions presented previously, such as meshing, diffraction orders, and reflections.
Model included. My BC's are Floquet PBC on the sides, impedance BC on the bottom (aluminum substrate) and a port with diffraction orders on the upper boundary.
At an angle, the phase distribution would shift as I change the height of the air port--is this the source of my disrepancy? I have tried adding a phase shift such as ky*delta_h, where delta_h is the change in height from a baseline model (height of 4*period), but the two results still differ significantly.
Any thoughts?
Thanks for your attention!
-ado
When performing 2-D full-field simulations of an opaque periodic structure at off-normal incidence, my results (near- and far-field profiles) vary as a function of the height of the upper (air) region. At normal incidence, however, there is good agreement.I know this topic has been addressed, but I have accounted for the solutions presented previously, such as meshing, diffraction orders, and reflections.
Model included. My BC's are Floquet PBC on the sides, impedance BC on the bottom (aluminum substrate) and a port with diffraction orders on the upper boundary.
At an angle, the phase distribution would shift as I change the height of the air port--is this the source of my disrepancy? I have tried adding a phase shift such as ky*delta_h, where delta_h is the change in height from a baseline model (height of 4*period), but the two results still differ significantly.
Any thoughts?
Thanks for your attention!
-ado