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How to correctly define a PML?
Posted 19.05.2011, 22:41 GMT-4 RF & Microwave Engineering 1 Reply
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Dear Users,
I am trying to simulate the transmittance spectrum of Au nanostructure hexagonal array, which the diameter is 200nm, the thickness is 40nm and the pitch is 400nm, coating on ITO/glass (200nm/1mm) substrate. The wavelength range is from 400nm to 700nm in vacuum.
The incident field is defined using "scattering boundary condition" at the top boundary of air subdomain which the wave type is plane wave, E-field is (1,0,0), and wave direction is (0,0,-1).
I truncate the thickness of the glass subdomain to 500nm and build a 500nm-thick PML subdomain below the glass subdomain, the refractive index of the PML is equal to the refractive index of glass.
The type of PML is Cartesian and the absorbing value is lambdaS_rfw in z-direction. The bottom boundary of PML subdomain is set as plane wave type scattering boundary condition.
Unfortunately, there is still some reflection and the transmittance spectrum is quite different from 400nm to 535nm when I modified the thickness of glass subdomain to 1000nm. There must be something wrong when I setting the PMLs.
The transmittance power is calculated by performing a boundary integration of Power outflow, time average over the boundary of glass/PML interface. The incident power is calculated manually, Pav_in=1/(2*120*pi)*Area.
What are the correct PMLs settings to achieve a perfectly absorbing boundary and minimize the reflection?
Best Regards,
Chun-Ying
I am trying to simulate the transmittance spectrum of Au nanostructure hexagonal array, which the diameter is 200nm, the thickness is 40nm and the pitch is 400nm, coating on ITO/glass (200nm/1mm) substrate. The wavelength range is from 400nm to 700nm in vacuum.
The incident field is defined using "scattering boundary condition" at the top boundary of air subdomain which the wave type is plane wave, E-field is (1,0,0), and wave direction is (0,0,-1).
I truncate the thickness of the glass subdomain to 500nm and build a 500nm-thick PML subdomain below the glass subdomain, the refractive index of the PML is equal to the refractive index of glass.
The type of PML is Cartesian and the absorbing value is lambdaS_rfw in z-direction. The bottom boundary of PML subdomain is set as plane wave type scattering boundary condition.
Unfortunately, there is still some reflection and the transmittance spectrum is quite different from 400nm to 535nm when I modified the thickness of glass subdomain to 1000nm. There must be something wrong when I setting the PMLs.
The transmittance power is calculated by performing a boundary integration of Power outflow, time average over the boundary of glass/PML interface. The incident power is calculated manually, Pav_in=1/(2*120*pi)*Area.
What are the correct PMLs settings to achieve a perfectly absorbing boundary and minimize the reflection?
Best Regards,
Chun-Ying
1 Reply Last Post 20.05.2011, 01:10 GMT-4
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Posted:
1 decade ago
Did you try adding a far-field calculation at the PML-Regular Domain interface? I figure that maybe that "Homogenizes" the outgoing signals so that the angles it actually hits the PML at are in line with the coordinate reference frame of the PML-that is: I think, but not too sure about this, that the PML will only absorb waves coming in at a certain angle, and that that is regulated by the center coordinate parameter (at least for spherical PML). The reason that I think this is that in my acoustics problem, the PML gave error messages until I added the far-field calculation. Does that help?
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Arts, crafts and sciences uplift the world of being and are conducive to its exaltation.
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Arts, crafts and sciences uplift the world of being and are conducive to its exaltation.
~Baha'u'llah