tpt-optics

A pure-Rust, AI-native computational optics and photonics library: geometric optics (ray tracing), wave optics (Fourier optics, beam propagation), polarization analysis, photonic device modeling, and optical design optimization — with no C/C++ FFI and no external optical solver dependencies.

• License: MIT OR Apache-2.0 (dual), © TPT Solutions.
• Dependency policy: every dependency is MIT-only or MIT/Apache-2.0 dual; crates whose only license is Apache-2.0 are forbidden (enforced via deny.toml and cargo deny check).
• Core philosophy: unit-safe, no_std + alloc-compatible at the core, differentiable for inverse optical design, and mathematically rigorous — every solver is implemented from scratch and verified with property-based tests and Kani bounded model checking harnesses.

Crates

Crate	Purpose	no_std
tpt-optics-core	Wavelength/frequency units, refractive index, dispersion models (Sellmeier, Cauchy, Schott, Drude–Lorentz, tabulated), material database, Fresnel coefficients, small dense linear algebra, complex numbers, dual numbers (forward-mode AD), Bessel functions, RNG	✅
tpt-optics-geometric	Sequential + non-sequential ray tracing, spherical/aspheric/Zernike/diffractive surfaces, ABCD matrices, paraxial optics, Monte-Carlo stray light	✅
tpt-optics-wave	Scalar diffraction (Fresnel/Fraunhofer/angular spectrum), FFT, Gaussian beams (q-parameter), BPM, PSF/OTF/MTF, coherence theory	✅
tpt-optics-polarization	Jones/Mueller calculus, Stokes vectors, polarization ray tracing, birefringence, dichroism, optical activity	✅
tpt-optics-waveguide	Slab/step-index fiber mode solving, effective index method, coupled-mode theory, photonic crystals, MZI/ring/AWG devices, scalar FEM	➖ (std feature)
tpt-optics-design	Merit functions (spot, wavefront, distortion, chromatic), damped least-squares / simulated annealing / genetic optimization, Monte-Carlo tolerancing	➖
tpt-optics-io	Zemax .zmx / CODE V .seq import-export, Zemax AGF glass catalog import, embedded reference glasses	❌ (std)
tpt-optics-verify	proptest strategies, optical invariants (Snell reversibility, ABCD symplecticity, energy conservation), Kani proof harnesses	➖
tpt-optics	Umbrella crate with feature-gated re-exports of all of the above	➖

Quick start

[dependencies]
tpt-optics = { version = "0.1", features = ["full"] }

use tpt_optics::prelude::*;

// Wavelength of the helium-neon laser line.
let wl = Wavelength::from_nm(632.8);

// Refractive index of BK7 at that wavelength via the Sellmeier model.
let bk7 = Sellmeier::bk7();
let n = bk7.index(wl).re();
assert!((n - 1.514_72).abs() < 1e-4);

See each crate's rustdoc for full examples (cargo doc --open).

Development

just check   # fmt + clippy + test + cargo-deny + no_std gate
just test    # tests only

Repository automation lives in the xtask crate; justfile recipes delegate to it so local dev and CI run exactly the same gate.

Scope and deviations from spec.txt

The spec lists internal tpt-* sibling crates (tpt-math, tpt-dsp, tpt-fem, tpt-materials, tpt-systems-optimisation) as dependencies. Their git locations are unconfirmed (placeholder org), so tpt-optics is fully self-contained instead: FFT, dense linear algebra, eigensolvers, optimizers, and RNG are implemented from scratch inside the workspace, in line with the "zero external solver dependencies, from-scratch implementations" principle. When the sibling crates stabilize, the internal modules can be swapped behind those dependencies without API changes.