Theory

Structure Design Guide

Design trade-offs for incident/exit media, substrates, and functional coating layers, plus external tutorials to learn from

Before a simulation, structure design fixes what the stack is made of — the incident and exit media, the substrate, and the layers that provide anti-reflection, high-reflection, filtering, or beam-splitting — and turns the design goal into a computable multilayer arrangement. This article maps those decisions to the app's structure page and collects external tutorials you can open and learn from directly.

Chapter Scope

Decision targetKey questionStructure-page counterpart
Incident/exit media and substrateTransmission window, reference index, environmental and mechanical limitsTop/bottom semi-infinite media and the substrate layer material
Functional coating layersAnti-reflection, high-reflection, metallic, or filter stackMaterial, thickness, and stacking order of each layer
Beam-splitting devicesSplit ratio, polarization, and angle-of-incidence dependencePartial-reflector stacks and plate/cube/wedged geometry

Incident/Exit Media and Substrate

The substrate is the mechanical carrier for the coating and sets the usable transmission window; its refractive index is the reference baseline for anti-reflection and high-reflection design. In simulation, the top/bottom semi-infinite media and the substrate layer together fix the boundary conditions of the whole stack, so settle them first.

Functional Coating Types

Functional layers fall into four design goals: anti-reflection coatings lower interface reflection; dielectric high-reflection coatings build a high-reflectance band from quarter-wave stacks; metallic mirrors give broadband reflection; filters transmit or reflect selected bands. Each maps to a specific multilayer thickness-and-material arrangement.

Beam-Splitting Devices

A beamsplitter is a partial-reflector thin-film device that reaches a target split ratio by controlling stack reflectance; its polarization and angle dependence come from the Fresnel response of the layers and the device geometry (plate, cube, wedged).

External Learning Resources

Authoritative external optical tutorials and design guides, grouped into general introductions and specific design goals. Open them to learn the structure-design points above.

General Coating Design

By Design Goal

Material Optical Constants

  • refractiveindex.info — Database of refractive index n and extinction coefficient k for optical materials; check material dispersion before designing.
All links point to external sites, mostly in English, and are for learning principles and design methods. Always rely on your own simulation settings for specific materials and stacks. Some sources (e.g. RP Photonics) also sell commercial products; this manual cites only their public encyclopedia/tutorial pages.

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Continue with Depth-Resolved Quantities and Structure Configuration.

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