The Zemax Coatings window reads and writes Zemax OpticStudio
COATING.DAT files. Import a coating stack (and its materials) from a
COATING.DAT into a TFStudio design, or export the active design as a COAT
stack plus its MATE material definitions for use in OpticStudio.
COATING.DAT is Zemax’s coating database — a text file of MATE (material)
and COAT (coating-stack) records, alongside the ideal and tabular coating
models (IDEAL, IDEAL2, TABLE, TAPR, ENCRYPTED). The window parses the
whole file and presents it in three tabs: Coatings, Materials, and
Export. Load a file with the Load button at the top; the parsed
contents and your selections stay put while you switch between tools.
Settings
Section titled “Settings”Reference wavelength — λ₀ used to convert between Zemax’s relative thickness (in waves) and physical thickness in nanometres on both import and export.
Coatings tab — lists every COAT stack in the file with its type and layer
count. Select a layer stack and press Import to front to load it as the
front design; the stack’s MATE materials are auto-registered into a
Zemax <file> catalog so the design resolves its materials immediately.
Encrypted stacks are locked and cannot be imported.
Materials tab — lists every MATE table. Tick the ones you want and use
Import selected or Import all to add them to a catalog without touching
the design.
Export tab — generates COAT + MATE text from the current front design,
with a live preview before you save:
- Thickness mode — write absolute thickness (µm) or relative waves.
- Material scope — export only the materials used by the design, or all catalog materials.
- Coating name — the
COATrecord name. - Sample grid — the wavelength range and step at which each material’s
n,k is tabulated into its
MATErecord.
How to read it
Section titled “How to read it”TFStudio and Zemax differ in a few conventions, which the window handles for you automatically:
| Quantity | Zemax | TFStudio |
|---|---|---|
| Wavelength | micrometres (µm) | nanometres (nm) |
| Extinction | stores −k | k > 0 (sign flipped on I/O) |
| Layer thickness | relative T (waves) |
physical d = T·λ₀ / n₀ |
| Layer order | outermost → substrate | same internal storage order |
Layer order needs no reversal — Zemax’s outermost-to-substrate order is exactly
how TFStudio stores the front coating (the Design Editor only displays it
reversed). Round-tripping a design out to COATING.DAT and back in preserves
both the layer thicknesses and the k-sign convention. Only IDEAL, IDEAL2,
and TABLE style material models map cleanly to TFStudio dispersion;
ENCRYPTED Zemax materials cannot be decoded.
References
Section titled “References”- Zemax OpticStudio Help → The Coating Tab → Coating File Definitions
(
MATE,COAT,IDEAL,TABLE), the source of theCOATING.DATformat.