TFStudio

What is TFStudio?

TFStudio is a desktop application for designing, analyzing and synthesizing multilayer optical thin-film coatings. It implements the Transfer Matrix Method (TMM) following Macleod’s Thin-Film Optical Filters (5th ed.) and a full synthesis stack (Damped Least Squares refinement, Sullivan & Dobrowolski numerical needle, Tikhonravov gradual evolution).

This site is the reference manual. Every tool window inside the app has a ? button that opens the matching page here. The contents below are grouped by what the tools do, so a page is easy to find from the window it documents.

Contents

Design

Design EditorBuild and edit the coating: layer stack, substrate, media, and the surface you are designing.

Material EditorBrowse, import and create optical materials: the n(λ), k(λ) data every coating layer uses.

SpecificationState your design requirements as PASS/FAIL qualifiers, and turn them into a merit function.

Stack FormulaGenerate a whole layer stack from a compact symbolic formula like Air | (HL)^4 H | Glass.

Edge FilterBuild an edge filter from two materials whose s and p edges fall at the same wavelength at an oblique angle.

Analysis

Optical EvaluationSpectral reflectance, transmittance and absorptance of the active design.

Wavelength vs AngleT, R or A mapped over wavelength and angle of incidence at once.

Color EvaluationCIE chromaticity, Lab and color readouts that show what your coating looks like to the eye.

Admittance DiagramThe optical admittance locus through the stack, and the design intuition it gives at a glance.

Electric FieldThe |E(z)|² standing-wave profile through the stack.

EllipsometryΨ and Δ, the amplitude-ratio and phase quantities an ellipsometer measures.

GD / GDDSpectral phase and its derivatives, the diagnostics for chirped mirrors and ultrafast coatings.

RI Profilen(z) and k(z), the index step profile of the stack at a chosen wavelength.

Layer ThicknessesEvery layer of a coating as a bar, in physical or optical thickness units, colored by material.

Integral ValuesWeighted spectral averages such as Tvis, Tsol, TUV and TNIR.

Plot EngineBuild custom multi-curve XY plots, or map a quantity over two swept variables.

Tolerance

Monte CarloSee how random manufacturing errors blur your spectrum and what yield to expect.

Layer SensitivitySee which layers are the most critical to manufacture accurately.

InhomogeneitiesModel graded transition layers and see how a non-step interface changes your spectrum.

Systematic DeviationsApply a correlated thickness or index shift across the whole stack and sweep its effect.

Roughness / ScatteringEstimate scatter loss from interface roughness and the specular R and T that survive it.

Optimization

Merit Function EditorTargets, operands, weights and thickness constraints: what the optimizer drives toward.

Operand ReferenceEvery merit-function operand: what it computes, its arguments, and how it drives the optimizer.

RefinementAdjust layer thicknesses to minimize the merit function, with a choice of optimization methods.

NeedleInsert thin needle layers where they improve the merit function, then refine. Automatic and manual.

Gradual EvolutionNeedle optimization wrapped in an outer loop that forces insertions to escape local minima.

Structural OptimizerRestructure the stack by adding, removing, splitting, merging or perturbing layers, with a simulated-annealing accept.

VariatorLive sliders for what-if exploration: per-layer thickness, substrate, and per-material n/k.

Design CleanerMerge adjacent same-material layers and remove very thin layers, then optionally re-refine.

Filter DesignBuild a multi-cavity Fabry-Perot bandpass prototype (DWDM, LWDM or notch) in a few guided steps.

Optimization MethodsEvery refinement and synthesis algorithm: what each does and when to pick it.

Simulation

BBM SimulatorSimulate making your coating under a broadband optical monitor and see the as-built spectrum.

Mono SimulatorSimulate a single-wavelength monitor, with turning-point, level or timed cut strategies per layer.

Monitor WorksheetCheck, layer by layer, whether the design can be terminated on an optical monitor and on which witness chip.

Data Exchange

Measured SpectraImport measured R/T/A spectra as overlays, and export curves to CSV or JCAMP-DX.

Measured EllipsometryImport a measured Ψ and Δ pair from a spectroscopic ellipsometer, compare it against the design, and export measured or calculated Ψ/Δ as CSV.

n,k CharacterizationDerive a film's refractive index, extinction coefficient and thickness from a measured R/T spectrum or a measured Ψ/Δ pair, and save the result as a material.

Zemax CoatingsRead and write Zemax OpticStudio COATING.DAT, including materials and coating stacks.

CODE V CoatingsRead CODE V MUL coatings from .seq and .mul files, and write a design as a .seq file for CODE V.

Process ExporterPlay back your coating layer by layer and export per-step deposition data.

Information

ReportAssemble a document from blocks over one or several designs, then save it as a PDF or a single HTML file.

Edit

HistoryBrowse and jump to any previous state of the active design.

Concepts

Surface & Evaluation ModesThe two controls that decide which coating is optimized and what every window evaluates.

Conventions used throughout this manual

• Wavelength in nanometres (nm).
• Angle of incidence (AOI) measured from the surface normal, degrees.
• Polarization s (TE), p (TM), or avg = ½(R_s + R_p).
• Sign convention of the complex refractive index: ñ = n + ik (k ≥ 0 for absorbing media), with the time-harmonic factor exp(−iωt). This is the complex conjugate of Macleod’s ñ = n − ik / exp(+iωt) form (§2.2); results are identical, phases carry the opposite sign.
• Absorbing incident medium (a cemented cube, an immersion liquid): every angle in the stack follows from n₀ sin θ₀ with n₀ the real part of the index (Macleod §10.2). R is |r|², the reflected wave against the incident wave at the surface. T is measured against the irradiance the incident medium alone would carry, Macleod’s Eq. 2.83, which the book gives at normal incidence and TFStudio applies at every angle. With Ignore other side on, A is what the coating’s layers absorb, and R + T + A differs from 1, either way, by the interference of the incident and reflected waves inside the absorbing medium: second order in k₀ on a bare interface, first order over a coating, and able to reach tens of percent beyond the critical angle or near grazing incidence. R alone can come out above 1. The light the coating sends back is then 1 − T − A, not R. With Ignore other side off, A is 1 − R − T, never below 0, and takes that term in.
• Layer 1 = layer touching the substrate (first deposited).