Layer Sensitivity shows which layers are the most critical to make accurately. It nudges each layer’s thickness by a small amount, measures how much the optical performance changes, and ranks the layers by that change. The layers at the top of the ranking are the ones that need the tightest monitoring and process control.
Settings
Section titled “Settings”Probe size — how big a thickness change to test on each layer. Choose Relative (a percentage of the layer’s own thickness, 1 % by default — the usual choice, since real errors scale with thickness) or Absolute (a fixed amount in nanometres). The sign does not matter; the tool always tests the same amount above and below nominal.
Display — show the result as a chart, a table, or both.
Scale — Normalized sets the most sensitive layer to 100 % and scales the rest against it (the easiest way to compare layers), or Absolute shows the raw change in merit on a logarithmic axis (use this when one layer dominates and you want its true size).
The ranking is evaluated for the surface mode set in the Design Editor (front, back, both, or symmetric), shown as a badge on the window.
How to read it
Section titled “How to read it”Each bar is one layer. A tall bar means a small thickness error there produces a large change in performance — a critical layer that needs a tight tolerance. A short bar means the layer is forgiving. A design whose bars are all about the same height is robust, with no single layer that can ruin it.
Layers are numbered as in the Design Editor (layer 1 touches the substrate), and locked layers are excluded. Sensitivity is measured against the optical performance, so the ranking reflects the effect on the spectrum.
References
Section titled “References”- H. A. Macleod, Thin-Film Optical Filters, 5th ed., §13.7.