Quick Start
0. Open the Refractive-Index Fitting Module
You can access the refractive-index fitting module via:
- Main Menu > Film Stack > Refractive Index Fitting
- Home > Refractive Index Fitting
1. Choose Fitting Mode
Select either single-layer or single-layer-with-protective-coating mode depending on the sample.
1.1 Single-layer
Use this mode for stable, transparent dielectric films (e.g. SiO2, TiO2, Al2O3). A known substrate refractive index is required (fit the substrate first if unknown).
1.2 Single-layer with protective layer
Use this mode for films that have a protective or capping layer (common for metals like Ag, Al, Cu). When choosing a protective layer consider stability, repeatability, high transmittance, and known optical constants.
2. Prepare Samples
2.1 Film thickness
Prefer measured spectra that are not at spectral extrema. Avoid samples where features sit at the instrument limit.
3. Measurement Data
3.1 Online instruments
Use configured online testers; exported formats may vary.
3.2 Offline instruments
Use lab photometers (e.g. Lambda 900); common export format is CSV.
4. Load Data and Create Spectrum Target
Convert measured spectra to a spectrum target for fitting.
5. Set Initial Values
Provide theoretical or empirical starting values for refractive index and thickness.
6. Fit
Click the Fit button to start the optimization.
7. Inspect Results
Results are stored in a list — inspect candidates and load preferred results into the main view.
8. Save Results
Export fitted n/d values to TXT or save into the database via the right-arrow action on the fitted layer list.