Weird Memory usage when using Prism

[raksharuia]

Hello MEEP community,

I am working on simulating an elliptical micropillar structure (a cavity sandwiched between a top and bottom DBR). I build this geometry by stacking up elliptic cylinders. I notice that the memory usage differs significantly depending on whether the elliptic cross-section is created using the Prism object (defining points on the ellipse boundary) or using multiple Block objects that approximate the ellipse area.

This discrepancy occurs even when both geometries are visually identical and I use the same resolution and domain parameters.

The following table shows my findings when the script was run to set the geometry and run a test simulation for a small time [figure below]. (I ran my code on a CPU with 32 cores and 64 GB of RAM)

I created 3D simulations with identical cell size, source (point Electric dipole polarized along y-axis), grid resolution, and compared two orientations of the ellipse’s major axis for both the Prism and Block geometries.

• Ellipse with its major axis along x-axis (with symmetry setting)
• Ellipse with it major axis along x-axis (without using any symmetry)

Symmetry used : [mp.Mirror(direction=mp.Y, phase=-1), mp.Mirror(direction=mp.X, phase=1)].

The results of my tests are in the image below -

Does the prism geometry trigger some intermediate memory allocation? Is this extra memory usage from curved polygonal surfaces known?

Thank you in advance for you reply :-)

Raksha

[stevengj]

The memory allocation for the prism object itself should be tiny, so I'm not sure what is going on here.