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simulate total internal reflection
Posted May 2, 2010, 11:11 p.m. EDT 2 Replies
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Hi I am using COMSOL 3.5a to test one simple case.
2D. interface between glass (n=1.5) and air (n=1). i add PML at top and bottom.
i want to simulate an incident tilted plane wave enter glass layer from top, the boundary condition i use at the two sides is Floquet periodicity with k = the k vector for the plane wave.
the boundary condition at the two PML is scattering boundary condition.
i solve for scattered TM.
I expect that for incident angle > 41.8 degree, i will observe total internal reflection, where the wave in Air will propagate in x direction, with magnitude exponentially decay in y direction.
However, if my incident angle is 0.5*pi, i can get the total internal reflection; for all other incident angles, i did not observe this. when i plot out the scattered Hz, I see that the Hz in Air is not an evanescent wave.
Anyone knows what is the possible mistake? thanks a lot!
2D. interface between glass (n=1.5) and air (n=1). i add PML at top and bottom.
i want to simulate an incident tilted plane wave enter glass layer from top, the boundary condition i use at the two sides is Floquet periodicity with k = the k vector for the plane wave.
the boundary condition at the two PML is scattering boundary condition.
i solve for scattered TM.
I expect that for incident angle > 41.8 degree, i will observe total internal reflection, where the wave in Air will propagate in x direction, with magnitude exponentially decay in y direction.
However, if my incident angle is 0.5*pi, i can get the total internal reflection; for all other incident angles, i did not observe this. when i plot out the scattered Hz, I see that the Hz in Air is not an evanescent wave.
Anyone knows what is the possible mistake? thanks a lot!
2 Replies Last Post Aug 7, 2010, 8:43 a.m. EDT
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Posted:
1 decade ago
Hi Lin,
Are you using the Scattered Harmonic Mode?
Also, have you checked whether the reflections and transmissions at the COMSOL air-glass (or glass-air in your case) interface are consistent with the Fresnel equations? - I am personally having problems with this right now!!
Which domain/s is/are your source/s limited to?
If you are facing the same problem as me, then it could explain why you don't see a total internal reflection at the boundary.
I am trying to frantically work out why there are these discrepancies in reflection,
If you wish to attach your model, I could take a look at it and advice on some of the thumb-rules I try to stick to.
cheers,
Best Regards,
Prateek
Are you using the Scattered Harmonic Mode?
Also, have you checked whether the reflections and transmissions at the COMSOL air-glass (or glass-air in your case) interface are consistent with the Fresnel equations? - I am personally having problems with this right now!!
Which domain/s is/are your source/s limited to?
If you are facing the same problem as me, then it could explain why you don't see a total internal reflection at the boundary.
I am trying to frantically work out why there are these discrepancies in reflection,
If you wish to attach your model, I could take a look at it and advice on some of the thumb-rules I try to stick to.
cheers,
Best Regards,
Prateek
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Posted:
1 decade ago
hi, guys, have you fixed your proplem?
I am also interested in the reflections and transmissions between dielectric interface.
I am also interested in the reflections and transmissions between dielectric interface.