Design Import

The Import button in the Project group of the Setup tab reads coating designs saved by TFCalc (.tfd), Essential Macleod (.dds) and OptiLayer (.dsg) and adds them to a project folder as TFStudio designs. Pick any number of files from any of the programs in one go; each file becomes one design.

The dialog

The left side lists every design that could be read, with its program, its layer count and how many of its material names still need a TFStudio material. Files that could not be read are listed underneath with the reason. Add files… appends another pick to the same batch.

The right side shows the highlighted design: incident medium, substrate, exit medium and reference wavelength, then the stack with the thickness each layer will have in nanometres, and beside it what the file says about the layer (its optical thickness, a lock). Anything the reader had to assume or leave out is written above the stack, and so is a layer whose thickness could not be computed. Below the stack is the materials table, and at the bottom the design’s transmittance, reflectance and absorptance at normal incidence over the file’s own plot range, once every material is assigned.

Materials. A design names its materials the way the program’s own database does. Each name is looked up in your catalogs by exact name, and the match is shown in the picker; a material imported from the same program is preferred over any other, a user catalog over the built-in library, and Air is always the built-in Air. Change any suggestion with the picker. A name is shared across the batch, so assigning it once covers every design that uses it. Import the program’s material files first (Material Editor, Import material files…) so the names are found. A name left unassigned is imported as a missing material: the Design Editor flags it, and Replace Materials fixes it later.

An OptiLayer design names its materials only by abbreviation, so the reader looks in the design’s folder: the project file’s abbreviation map when it has one, otherwise the material file whose index at the control wavelength is the one stored with the layer. The folder’s substrate files supply the media and, when the project does not name it, the substrate. A material found this way is marked “from the design’s folder” and travels inside the design, the way a .tfs file carries its materials, so the design computes with the definition it was made with. Pick a catalog material in its row to use that instead; the button beside the status gives the file’s definition back.

Footer. TFCalc files do not record their wavelength unit, but every layer carries both its quarter waves and its physical thickness, and the two agree only in the right unit, so the switch reads the unit from the file. Set it to nm or µm to override; the design then notes when the file disagrees. Choose the project folder, then Import. The Design Editor opens on the last design added.

What is refused

A rugate or graded-index design is listed under the files that could not be read, with the reason. OptiLayer’s rugate layers, Essential Macleod’s packing-density layers and TFCalc’s variable materials are those programs’ ways of building a graded index, and TFStudio has no graded layer to hold one.

How to read it

Quantity	TFCalc	Essential Macleod	OptiLayer	In TFStudio
Layer numbering	from the substrate	from the incident medium	from the substrate	stored the same way whichever program wrote it
Layer thickness	physical, nm; the QWOT is shown for reference	full-wave optical at λ₀, or physical	quarter waves at the control wavelength, with the index stored for the layer, at the match angle	physical nm; an optical thickness is converted with the layer’s index at λ₀, at the match angle where the file has one
Absorbing layer	physical, nm	optical with the real part of n	quarter waves with the real part of n; a layer whose index is too low for the wave to propagate at the match angle is converted at normal incidence and noted	physical nm
Reference wavelength	Environment, in the file’s unit, read from the layers	in the file’s unit	the control wavelength	nm
Back side	back layers	none	none	back stack; the surface mode follows
Exit medium	Environment; the same material as the substrate means a semi-infinite substrate, any other means both surfaces of the substrate are evaluated	the substrate is the emergent medium	the project file; the substrate is semi-infinite, the program’s default, since its Back Side option is not in the file	as in the file, with the evaluation mode set to match; the substrate material where the program has none, which means the same thing
Substrate thickness	Environment, mm	not used	not in the file	TFStudio’s default where the file has none
Constant index	none	a number written as a material name, when no catalog holds a material of that name	the stored index, when no folder material matches	a constant-index material embedded in the design
Locked layer	Optimize = No	Lock	status F	locked

The stack formula and its symbols, the incident angle of the file, the match angle, and anything the reader left out or assumed (optimization targets, layer groups, linked layers, environments beyond the first, monitoring settings, a medium the project does not name) are written into the design’s Notes, in the language the program is running in.