User Tools
docs:become
Differences
This shows you the differences between two versions of the page.
| Both sides previous revision Previous revision | Next revision Both sides next revision | ||
|
docs:become [2020/04/14 14:19] pklapetek |
docs:become [2020/04/14 14:24] pklapetek |
||
|---|---|---|---|
| Line 10: | Line 10: | ||
| Calculations in 2D are performed using the GSvit2D solver which is an almost unused extension of GSvit to 2D calculations. As this was very outdated, most of the algorithms had to be implemented, incuding near-to-far field calculation and various materials treatment including dispersive metal treatment via PLRC algorithm. | Calculations in 2D are performed using the GSvit2D solver which is an almost unused extension of GSvit to 2D calculations. As this was very outdated, most of the algorithms had to be implemented, incuding near-to-far field calculation and various materials treatment including dispersive metal treatment via PLRC algorithm. | ||
| + | |||
| + | |||
| + | ---- | ||
| + | |||
| To test the correctness of the newly implemented code we compared a simple transmission grating diffraction pattern to the analytically known solution. | To test the correctness of the newly implemented code we compared a simple transmission grating diffraction pattern to the analytically known solution. | ||
| Line 27: | Line 31: | ||
| {{:docs:methods_explanation_humanized.png?600|}} | {{:docs:methods_explanation_humanized.png?600|}} | ||
| - | //Technical remarks: To calculate single aperture correctly it is important to add the side boundaries. It is also crucial to use CPML throughout all the | + | //Technical remarks: To calculate single aperture or three apertures in one computational domain correctly it is important to add the side boundaries. It is also crucial to use CPML throughout all the |
| calculations, otherwise we get everything dependent on the computational volume. | calculations, otherwise we get everything dependent on the computational volume. | ||
| If we manually setup the few apertures grating, result corresponds to the theory. | If we manually setup the few apertures grating, result corresponds to the theory. | ||
| - | However, using periodic boundary conditions and virtual repetitions are valid only if we sum many virtual repetitions for far field calculation. | + | However, using periodic boundary conditions and virtual repetitions are valid only if we sum many virtual repetitions for far field calculation, at least about 7. |
| - | Using this approach for only few apertures (e.g. 3) leads to wrong result (even if it looks fine at the diffraction order angle, by chance?). | + | Using this approach for only few apertures (e.g. 3) leads to wrong result (even if it still looks fine at the diffraction order angle, is it only by chance?). |
| - | On the other hand, summing virtual repetitions without periodic BCs does not lead to anything reasonable, we have to have them, to get the | + | On the other hand, summing virtual repetitions without periodic BCs does not lead to anything reasonable - we have to use periodic BCs, to get the |
| - | correct fields. | + | correct fields in the near field. |
| - | When higher orders are evaluated, the values of the central maximum can drop and using a smaller time step helps to correct this effect. | + | When higher numbers of apertures are evaluated (e.g. 11), the values of the central maximum can drop and using a smaller time step helps to correct this effect. |
| This might be related to the far field integration (linear interpolation works better when signal is not changing so rapidly), | This might be related to the far field integration (linear interpolation works better when signal is not changing so rapidly), | ||
| however it is still unclear if this is the only effect.// | however it is still unclear if this is the only effect.// | ||
| + | |||
| + | ---- | ||
docs/become.txt · Last modified: 2020/04/24 12:27 by pklapetek
Except where otherwise noted, content on this wiki is licensed under the following license: CC Attribution-Noncommercial 4.0 International
