What is the difference between the scattering BC and PML?

[faryafada]

Hi,
I want to know what is the proper boundary condition in COMSOL RF module to study optical interactions, Scattering BC and PML? or what is the difference between them? also I want to know if the rules are different for application of these two BCs in far-field and near-fields studies?

Thanks,
Farya

 

[soarce]

See here for instance http://www.comsol.com/community/forums/general/thread/12362/