2D FDTD ADI Boundary Conditions

hello all,

I am trying to modelize a plane TE wave and its interaction with an initial plasma density... forgetting the plasma, I have been thinking of using the ADI method to achieve faster results BUT I am facing problems with the B.C. of my problem when the courant number exceeds a value of 1 ... Till now i am using simple Silver-Muller B.C. and it seems that there is a lot of reflection.. has anybody tried the ADI method for such a case and what kind of BC would you recommend? (Mur's? PML? UPML? ... )

Thx !

Constantine