$RCWAabovelayer is the definition of layer number above the 1D-DDCC program.
For example, RCWA simulation 20 DBR layers. DDCC ran electrical problem from 21st layer, then
$RCWAabovelayer
20
The $RCWAabovelayer setting for 1D-DDCC in GUI interface
3.The number of layers above the epitaxial layer.