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Regarding PML and scattering boundary condition
Posted Nov 17, 2020, 1:29 a.m. EST Wave Optics Version 5.2a 1 Reply
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Dear Sir, I have two questions. 1. I am simulating an optical waveguide. I did not use any spherical PML layer. On the waveguide surface, I directly applied Scattering boundary condition. Then I am checking the far field pattern by applying far field domain on the whole model. I have chosen only top surfaces in far field calculation section to check the far field coming from upper surface. Is this the right process to measure far field or PML is mandatory for far field measurement?
- If I chose a spherical PML layer surrounded the model, then by default PEC is getting applied to the outer surface of the sphere. Now if I apply scattering boundary condition on the spehere surface to override the PEC condition, will it affect the far field? because we know we can apply either Scattering boundary condition or PML layer to absorbe scattered light.
Eagerly waiting for your response. Thanks in advance. Regards, Subhankar.
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You don't need to use a PML to compute the far field. A scattering boundary condition is fine. Overriding the PEC is the right thing to do (but.. see added note below).
Added: You will get a far more accurate computation if you include some computational space around the radiating surfaces of your optical waveguide, and put the scattering boundary condition on that surrounding space instead. (And in that case, the aforementioned PEC condition on the optical waveguide will disappear on its own, becoming an interior boundary.)
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