Dear communities:
Recently I am trying to model my 3D periodic structure with COMSOL 4.3b. The periodicity of my sturctuture is 1.5um, but the incident wavelength can be as low as 400nm, so that the diffraction order is very large.
At the beginning, I try to solve it using "plasmonic wire grating" model, since it directly calculates the reflectance and transmittance. However, I found it is a nightmare to including all the diffraction orders at the port BC. Especially you need to varify the correct (m,n) combinations.
Then the comsol support team suggest me to using a scattering wave + PML to avoid the unphysical reflection at the port BC (the model is too big to unload). The field distribution now looks nice, however, I cannot calculate the reflectance or the transmittance in this model. I tried to use the power outflow from the top surface 4*intop1(emw.Poavz*nz)/P0 to calculate the reflectance, but the results >>1 seems to be wrong.
I check on the forum, and I found that I am not the only one who encounter this problem. Therefore, I would like to know if anyone know how to calculate the reflectance and transmittance using scattering wave formulation + PML.
If you need to see the detail of the model, please feel free to email me at sunsong@ihpc.a-star.edu.sg.
Million thanks
Recently I am trying to model my 3D periodic structure with COMSOL 4.3b. The periodicity of my sturctuture is 1.5um, but the incident wavelength can be as low as 400nm, so that the diffraction order is very large.
At the beginning, I try to solve it using "plasmonic wire grating" model, since it directly calculates the reflectance and transmittance. However, I found it is a nightmare to including all the diffraction orders at the port BC. Especially you need to varify the correct (m,n) combinations.
Then the comsol support team suggest me to using a scattering wave + PML to avoid the unphysical reflection at the port BC (the model is too big to unload). The field distribution now looks nice, however, I cannot calculate the reflectance or the transmittance in this model. I tried to use the power outflow from the top surface 4*intop1(emw.Poavz*nz)/P0 to calculate the reflectance, but the results >>1 seems to be wrong.
I check on the forum, and I found that I am not the only one who encounter this problem. Therefore, I would like to know if anyone know how to calculate the reflectance and transmittance using scattering wave formulation + PML.
If you need to see the detail of the model, please feel free to email me at sunsong@ihpc.a-star.edu.sg.
Million thanks