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Some problems with the transmission and reflection model: Identity pairs
Posted 2011年4月25日 GMT-4 07:31 RF & Microwave Engineering Version 3.5a 4 Replies
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Hi all,
I want to build a model that calculate the transmission and reflection of light with the normal incidence. So I follow the model example ( Model ID: 6141 a Periodic Structure) to do such a modeling. I used the FEM model brewstersAngle3DTE.mph, except that I fixed incident angle theta=0, and I also the index of all the domains to be n_slab, since firstly I would like to check the light propagation in the homogenous dielectric medium, and the identity pairs that is used in the FEM structure brewstersAngle3DTE.mph
Then I got some problems, which has puzzled me for a long time. The problem is the following,
when n_slab=1, all the light is transmitted, as expected;
when n_slab=1.5, I found that 3.8 percent of the light is reflected, it starts to appear strange.
and when n_slab=2.5, I found that 15.51 percent of the light is reflected.
Since the index over all the domain is the same, so there should be no reflections, 15.51 percent is too large.
I donot think there is any problem with the mesh, since I use the same mesh strategy and use very dense mesh. I digged into the weak formulation of model, currently I am doubting the validity of constraints that applied on the destination boudary of the identity pair,
bnd.constrf = {0,0,0,0,0,0,0,{0;0;0;'if(src2dst_ip5,test(psi-src2dst_ip5(psi)),0)'}, ...
0,0};
bnd.constr = {0,0,0,0,0,0,0,{0;0;0;'if(src2dst_ip5,psi-src2dst_ip5(psi),0)'}, ...
0,0};
I attached the FEM here.
Any comments or hints? Thanks in advance
I want to build a model that calculate the transmission and reflection of light with the normal incidence. So I follow the model example ( Model ID: 6141 a Periodic Structure) to do such a modeling. I used the FEM model brewstersAngle3DTE.mph, except that I fixed incident angle theta=0, and I also the index of all the domains to be n_slab, since firstly I would like to check the light propagation in the homogenous dielectric medium, and the identity pairs that is used in the FEM structure brewstersAngle3DTE.mph
Then I got some problems, which has puzzled me for a long time. The problem is the following,
when n_slab=1, all the light is transmitted, as expected;
when n_slab=1.5, I found that 3.8 percent of the light is reflected, it starts to appear strange.
and when n_slab=2.5, I found that 15.51 percent of the light is reflected.
Since the index over all the domain is the same, so there should be no reflections, 15.51 percent is too large.
I donot think there is any problem with the mesh, since I use the same mesh strategy and use very dense mesh. I digged into the weak formulation of model, currently I am doubting the validity of constraints that applied on the destination boudary of the identity pair,
bnd.constrf = {0,0,0,0,0,0,0,{0;0;0;'if(src2dst_ip5,test(psi-src2dst_ip5(psi)),0)'}, ...
0,0};
bnd.constr = {0,0,0,0,0,0,0,{0;0;0;'if(src2dst_ip5,psi-src2dst_ip5(psi),0)'}, ...
0,0};
I attached the FEM here.
Any comments or hints? Thanks in advance
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4 Replies Last Post 2011年11月3日 GMT-4 10:05