Browser-based designLoading calculation engine…
OPTICAL COATING DESIGN
Thin Film Design
Calculate coating spectra, inspect optical fields, and refine multilayer designs.
COHERENT THIN-FILM OPTICSSpectra · fields · optimizationYour designs stay in your browser.
OPTICAL RESPONSE
Transmittance
A coating’s response, made visible.
Loading the local calculation engine and material references.
The first visit takes longer; subsequent visits use cached assets.
D65 · CIE 1931 2° · relative-luminance sRGB preview. Display gamut and calibration affect appearance.
COATING DESIGN
Layer stack
Stored from exit to entrance; incident light enters the last row. All table thicknesses, including the substrate, use the selected display unit. Changing display units preserves physical geometry. Calculations, stress inputs, and canonical exports use physical µm. Select controls editing; Refine selects optimization variables.
| Select | Layer | Material | Collection | Thickness (µm) | Role | Refine |
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Layer adjustments
Local material data
Add your own permitted optical constants as .nk files. Data stay in this browser session. Materials used by the design are included in saved projects. For the user collection, use three whitespace-separated columns: wavelength (µm), n, k; passive extinction k ≥ 0. To restore a legacy project, use its original collection and material name, and the unchanged file in that collection’s format. Invalid data are rejected.
CSV stores physical µm; collection and role are required.
DESIGN OBJECTIVE
Design goals
Power quantities R, T and A are fractions in Linear units. Inequalities are inclusive within the selected tolerance. Disabled goals are excluded from optimization.
| Select | Enable | # | λ (µm) | Quantity | Relation | Target | Weight |
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Generate goals & set properties
CSV stores Linear power fractions.
THICKNESS & STRUCTURE
Refine the design
No optimization has been run.
Retained candidate
| Layer | Material | Thickness | Role |
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MODEL & OPERATION
Model assumptions and workflow
Optical model
Planar, homogeneous, isotropic, passive layers with coherent interference. Entrance medium must be lossless. Refractive indices use n − ik, with k ≥ 0 for absorption. Wavelength and physical thickness are in micrometres; angles are in degrees.
Unpolarized power is the mean of s and p powers. Field, admittance, amplitude and delay diagnostics show separate s and p results rather than an invented coherent average.
Materials & limits
Each material is evaluated only within its supported reference range. Unsupported formulas and invalid data are rejected. Wavelength coverage, discretization and source dispersion affect every result.
Finite substrates remain coherent. This model does not include scattering, roughness, anisotropy, incoherent substrate averaging or manufacturing tolerances automatically.
Design workflow
Set the layer stack and spectrum, then Calculate. Mark internal films for Refine and enable weighted wavelength goals. Inspect convergence and feasibility separately before applying a retained candidate.
Project JSON preserves settings, units, stack and goals. CSV uses physical thickness and Linear power fractions. Calculations and file handling occur locally; closing the tab discards unsaved work.
Interpreting results
Group delay is undefined where an amplitude vanishes. CIE previews use D65 and the CIE 1931 2° observer; out-of-gamut display channels clip. Stoney stress is an estimate under the stated thin-film/curvature assumptions.
Optimization finds a local candidate, not a guaranteed global optimum. Validate the final design against application requirements, fabrication constraints and independent measurements.
Scientific validation
Run analytical limiting cases, reference regressions and bounded optimization checks in this browser. These checks establish the supported calculation behavior; they do not certify an individual filter design.
| Reference check | Result | Evidence |
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