Learning Forum

[filmartinelli]

Good morning,

I would like to calculate the field profile of a region that is embedded between two long periodic elements. Because I am interested only in the middle region (not the periodic one), I was planning to use the "Cell periodicity feature" for the two periodic structures at the side. I was reading on the reference manual that when using the EME profile monitor, the cell periodicity has to be avoided. It is not clear to me if the cell periodicity must be avoided at all in the entire simulation, regardless if the monitor ovelaps a region with the periodicity or not, or if it can be used as long as the monitor is placed in a region where the periodicity is not used.

For clarity purpose, here is my structure. The two blue areas are using the cell periodicity feature, whereas the middle area does not. The field reconstructed by the yellow monitor will be correct? 

[Guilin Sun]

As the website mentions, EME monitors will not capture the effects due to periodicity, since it needs to get the spatial information which is not available in GUI.

 

[filmartinelli]

Thank you for the reply. However, this is not clear to me. My monitor does not overlap with any area that uses the periodicity feature. The only areas that uses the periodicity feature are the one embedded in the blue rectangles. This area should be substituted by a transfer matrix that descirbes inputs and output amplitudes and phases. So the knowledge of the field distribution in the yellow area (without periodicity) should only depend on the amplitudes and phases of the fields that are entering this area which are fully described by the transfer matrices, and not by the spatial distribution of the field in the blue regions (with periodicity).
Isnt that the case? 

[Guilin Sun]

The pysics is correct with periodicity. But the monitor only records data in the GUI. It ignores the operation of periodicity by design.   You can file a feature request that allows the monitor to record data outside of the periodic structures: 

New Feature vote:   Vote new features, and file your feature request

If it is possible, oyu can simulate the S parameters for the DBR mirrors and the cavity part, and then you can use scattering matric method to combine the result. and then you may be able to analytically compute the field in the central region.

[filmartinelli]

Thank you, that was clear. On a separate question, is there any way to get the field amplitudes information divided by left and right propagating fields?

[Guilin Sun]

Field monitor canot record data when periodicity is there. Otherwise, you can use different monitor in different regions.