Variator
The Variator is a panel of sliders for exploring how sensitive a design is. Drag any slider and the spectrum responds instantly: layer-thickness and substrate sliders nudge the shared design, so every open window (Optical Evaluation, Admittance, the electric-field and color tools) re-renders live, while the Variator’s own plot overlays the perturbed curve on a dotted baseline. It is a fast, reversible way to see which parameter matters before you commit to anything.
Settings
Section titled “Settings”Per-layer thickness: one slider per front and back layer, ranging roughly ±20 nm (or ±20 % of the layer, whichever is larger) around its baseline value. The slider label shows the layer’s material and baseline thickness.
Substrate thickness: nudges the substrate thickness in millimetres around its baseline.
Δn and Δk per material: one pair of sliders per unique material in the
stack, applied as constant offsets to the dispersive n(λ) and k(λ). These
stay local to the Variator preview (other windows keep showing the
unperturbed materials), and k is held at or above zero.
Preview controls: set the wavelength range and angle of incidence for the plot, toggle the dotted baseline overlay, and show the merit-function targets (when the design has any). The evaluation target (Front / Back / Total) is shown as a read-only badge and follows the Design Editor.
Revert: zeros every slider and restores the original design. Each slider row also has its own reset, and double-clicking a slider snaps it back to baseline.
How to read it
Section titled “How to read it”The solid R and T curves are the perturbed design; the dotted curves are the untouched baseline, so the gap between them is exactly the effect of the sliders you moved. The quickest use is a tolerance gut-check: jiggle one layer and watch a stopband edge walk. If a small move shifts the spectrum a lot, that layer needs tight process control.
Because the thickness and substrate sliders feed the shared design, the change is live everywhere, but it is non-destructive: the first slider move sets one undo checkpoint, so a single Ctrl+Z (or Revert) returns the design to where it started. The baseline is remembered while you re-arrange the workspace, so your reference point survives moving the window around.
References
Section titled “References”- H. A. Macleod, Thin-Film Optical Filters, 5th ed., §13.7 (sensitivity of multilayer performance to thickness errors).