Free online transfer matrix method calculator for multilayer thin-film structures. Calculate reflectance, transmittance and absorptance spectra for TE, TM and unpolarized light using wavelength-dependent optical data.
Browser-based and free: 3,500+ optical-material datasets · custom n,k import · TE/TM and unpolarized light · R/T/A spectra · CSV, PNG and PDF export
Read the calculator documentation Open worked thin-film examples
The calculator uses the transfer matrix method to model the optical response of planar multilayer structures. It calculates wavelength-dependent reflectance, transmittance and absorptance for TE, TM and unpolarized light at a selected angle of incidence.
It can be used to analyse dielectric mirrors, distributed Bragg reflectors, anti-reflection coatings, Fabry–Pérot structures, absorbing films, metallic mirrors and other isotropic thin-film stacks.
Each layer can use a constant complex refractive index, a Cauchy model, a Sellmeier model, imported tabulated n,k data or a material selected from the built-in RefractiveIndex.INFO library.
The calculator checks whether the selected optical data cover the requested wavelength range and does not silently extrapolate unavailable values.
The transfer matrix method accounts for interference between forward- and backward-propagating waves at every interface in the multilayer stack. It is commonly used to analyse and design optical coatings composed of homogeneous, flat and parallel layers.
The current implementation assumes isotropic materials, coherent plane-wave illumination, specular reflection and semi-infinite incident and transmission media.
Read the documentation and calculation limitations before using the results for engineering or research decisions.
Open the multilayer optics calculator examples to load a quarter-wave anti-reflection coating, a TiO₂/SiO₂ distributed Bragg reflector, a silver mirror or a Fabry–Pérot structure.
| Term | B | C | |
|---|---|---|---|
| 1 | |||
| 2 | |||
| 3 |
| λ [nm] | n | k |
|---|---|---|
| 400.0 | 2.1382 | 0.0431 |
| 403.1 | 2.1256 | 0.0402 |
| 406.2 | 2.1140 | 0.0375 |
| 409.3 | 2.1031 | 0.0349 |
I’m developing this simulator and other tools for photonics and scientific engineering. Feel free to connect with me or send feedback.