Unit cell position numbers (UPNs) with respect to the x and y orientations on the metalens layer. p: unit cell period.
Once you have finished building a metalens in BUILD module, results will be exported to the directory `your_SMDPRO_project_folder/results/build` . In this folder, you will find txt files that contain the dimensions of all unit cells across the lens (e.g. dimensions\_style#.txt). In these files, the numbers to the right of the unit cell dimension symbols are the unit cell position numbers (UPNs). For example, for 'R1', 'R' stands for radius of the circular unit cell and '1' is the UPN. The UPN increases by 1 along the positive x direction in SMD PRO.
If the flip or translation option of GDS in SETTIGNS is used, then the same coordinate conversion should be applied to match the dimensions in the txt file with the shapes in the GDS file. For example, if GDS translation is used, the UPN '1' corresponds to the 'bottom right' unit cell in the GDS file instead of 'bottom left'.
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