logic of recognizing rectangular resnato modes

[yefj]

Hello I have constructed a rectangular resonator as shown bellow.
I can see two maximas both on Y nomal and Z normal,
How do i recognise what kind of TE_nml is that?
Thanks.
Z normal cutplane:

Y-normal curplane:

X-normal cutplane:

 

[PlanarMetamaterials]

In rectangular coordinates, simply count the number of half-wavelengths along each axis. It looks like you have a 201 mode.