Introduction
Dreapex TMM is an online thin-film optical simulation platform based on the Transfer Matrix Method (TMM). It can be used to simulate and design distributed Bragg reflectors (DBR), anti-reflection coatings, photodetectors, solar cell absorbers, optical filters, and other one-dimensional multilayer structures, with analysis covering reflectance/transmittance/absorptance, ellipsometric parameters (Psi/Delta), dispersion properties (phase/group delay/GDD/DGD), and depth-resolved field distributions.
Scope
Dreapex TMM is intended for structures that are stratified along the thickness axis and approximately uniform in the lateral directions. Typical model classes include:
- dielectric multilayer stacks
- absorbing films and conductive thin films
- film-on-substrate structures
- mixed coherent and incoherent stacks
It is appropriate when the primary quantities of interest are reflectance, transmittance, absorptance, ellipsometric response, depth-resolved field quantities, or dispersion properties (phase, group delay, GDD, DGD).
It is not the correct primary solver for laterally patterned structures, diffraction-dominated devices, or full three-dimensional electromagnetic problems.
Representative Use Cases
Dreapex TMM is suitable for several common thin-film engineering tasks:
| Use case | Primary quantities | Commonly used features |
|---|---|---|
| Coating design | low reflectance or high transmittance in a target band | Structure, Optics, Reflectance, Transmittance |
| Absorbing-layer analysis | total absorptance and layer-resolved absorption | Absorptance, Layer Absorption |
| Angle and polarization sensitivity | angular response and s/p dependence | Optics, Sweep, energy result pages |
| Ellipsometric modeling | Psi/Delta curve comparison | Optics, Ellipsometry |
| Depth-resolved field analysis | field enhancement, power flow, absorption density | Depth Distribution |
| Dispersion analysis | phase, group delay, GDD, DGD for pulse broadening and PMD evaluation | Phase, GD, GDD, DGD |
| Design-space exploration | parameter trade-offs and constrained search | Sweep, Optimizer, Optimization Report |
The "Commonly used features" column in the table above can serve as a direct navigation entry point to the corresponding result pages.
Core Capabilities
The current application is organized into the following functional blocks:
| Functional block | Main content |
|---|---|
| Structure definition | Layer order, thickness, refractive-index model, layer groups, surrounding media, and RI database browser in Structure |
| Optical condition setup | Angle, polarization, wavelength mode, detector set, cone angle averaging, and incident spectrum in Optics |
| Standard calculation | Run for a baseline spectral solution |
| Parameter sweep | Sweep and Run Sweep for controlled parameter variation |
| Optimization | Optimizer and Run Optimizer for target-driven parameter search with Scalar, Curve Fit, and Color Match goal types; algorithms include TRF, L-BFGS-B, and Nelder-Mead |
| Result analysis | Result pages for spectra, color, ellipsometry, dispersion, depth profiles, and optimization history |
The available result groups are:
| Result group | Representative pages | Typical question answered |
|---|---|---|
| Energy results | Reflectance, Transmittance, Absorptance | Does the overall stack meet the spectral target? |
| Layer-resolved absorption | Layer Absorption | Dominant absorbing layer |
| Spectrum and color | ...Spectrum, ...Color pages | Relation between optical spectrum and perceived color |
| Ellipsometry | Psi, Delta | Sensitivity of the ellipsometric response to structure changes |
| Dispersion | Phase, GD, GDD, DGD | Pulse broadening, group delay dispersion, and polarization mode dispersion |
| Depth-resolved quantities | Poynting Vector, Absorption Density, Electric Field, Refractive Index | Through-thickness variation of field and energy quantities |
| Optimization output | Optimization Report | Did the target converge, and what parameter set was found? |
Practical Advantages
Compared with a script-only workflow or fragmented post-processing, Dreapex TMM offers the following direct advantages:
| Advantage | Practical meaning |
|---|---|
| Visual model setup | Structural and optical parameters can be edited directly in the interface |
| Integrated workflow | Modeling, execution, logs, and result review are kept in one environment |
| Suitable for both entry-level and advanced work | A baseline calculation can be extended naturally into sweeps, optimization, ellipsometry, and depth analysis |
| Efficient parameter comparison | Parameter variations can be explored and compared without rebuilding the model from scratch |
| Good fit for iterative engineering analysis | Supports the repeated loop of model definition, calculation, validation, and refinement |
Next Step
Continue with Quick Start to build a simple DBR structure and complete your first reproducible calculation.