oct_bscan_simulate — OPTICS oct op

• Data kinds: none → table (an op determined by its arguments alone — it takes no image or data input)

• Call: import fullseye as fs; fs.ledger.oct_bscan_simulate(sample2d=None, width_um=1500.0, n_columns=256, center_nm=840.0, bandwidth_nm=50.0, mode='sd', n_pixels=1024, wl_min_nm=None, wl_max_nm=None, spectrometer_fwhm_px=1.0, linewidth_nm=None, sweep_nonlinearity=0.0, photons_ref_per_pixel=20000.0, photons_mirror_per_pixel=None, eta=0.8, sigma_d=10.0, K=1.0, beam_waist_um=6.0, focus_um=None, illumination='point', focus_medium_index=1.5, oversample=4, noise=True, seed=0) (to call the implementation directly, import octscan; octscan.oct_bscan_simulate(sample2d=None, width_um=1500.0, n_columns=256, center_nm=840.0, bandwidth_nm=50.0, mode='sd', n_pixels=1024, wl_min_nm=None, wl_max_nm=None, spectrometer_fwhm_px=1.0, linewidth_nm=None, sweep_nonlinearity=0.0, photons_ref_per_pixel=20000.0, photons_mirror_per_pixel=None, eta=0.8, sigma_d=10.0, K=1.0, beam_waist_um=6.0, focus_um=None, illumination='point', focus_medium_index=1.5, oversample=4, noise=True, seed=0); from the registry, opsoptics.get("oct_bscan_simulate"))

Usage

A bundle of spectral interferograms forming a B-scan, scanned laterally across a cross-section (sample2d) (table).

> The detailed description below is the original text — the summary and the headings are translated.

sample2d = {"materials": [周囲, 層 1, …, 基板], "interfaces_um": [(W_fine,) の物理深さ, …] (上から、W_fine は任意の本数で横に線形補間。深さ 0 = 周囲の媒質の中の基準面)、"surface_um": 基準面の光路(参照腕との差、空気中 µm)、"scatter": [{"layer": i, "density_per_mm2", "amplitude"}] (断面内の点散乱体 —— 塗装の顔料・接着剤のフィラー)、

"inclusions": [{"x_um", "z_um", "radius_um", "material"}] (空洞・異物。上下の面で反射し、その下の界面の光路を変える)、"points": [{"x_um", "z_um", "amplitude"}] (置いた点散乱体 —— 横の点像の採点用)、"attenuation_per_mm": 層ごとの減衰}。省略時は段差を越えるコートの例。

各列: 細かい横の副標本(ビーム半径の 1/3 間隔)ごとに上から材料の区間を作り、境界 = 反射体、光路 = 材料ごとの距離。ビームの重み exp(−2(x − x')²/w(z)²)(往復、w(z) = w0 √(1 + (Δz/z_R)²))、

共焦点の結合: illumination="point" は (1 + u²)^(−1/2)、"line"(ライン照明、片方向だけ共焦点)は(1 + u²)^(−1/4)、u = (z − z_f)/z_R、z_R = π w0² n/λ0。ライン照明は 1 回で全列を撮る(走査の時間ずれなし)。

返り値: dict(kind="oct_bscan_spectra", spectra (W, N), wavelength_nm, k_rad_per_um, reference_spectrum, sample_only_spectrum(列ごとの試料腕だけ・雑音なし —— 自己相関のアーチファクトの素), x_um, truth={interfaces_um (n_if, W), inclusions}, settings)。

Family-wide input contract (fail-closed)

Every optics op validates its input before computing (nothing slips through silently):

• Units are baked into the argument name — _mm / _um / _deg / _mrad. Confusing mm with µm does not crash; it yields a plausible-looking wrong answer, so the name prevents it. Nothing here guesses the unit from the magnitude.

• Strings raise ValueError — float('50') succeeds, so an unparsed configuration value would slip through as a length (measured: thin_lens('50', '200') returned a plausible 66.667 mm). bool is refused too, as the implicit promotion True == 1.

• complex / masked arrays raise ValueError (real-valued slots only; silently dropping the imaginary part or peeling off the mask is refused). NaN/Inf raises ValueError on every input.

• Division by zero and its relatives are refused by name: focal length 0, radius of curvature 0, refractive index <= 0, a fully opaque aperture (all zeros, so the normalisation is 0/0), a PSF whose sum is <= 0, a Stokes vector with S0 = 0, and an object sitting at the front focal point (the image is at infinity).

• Only two ops return a non-finite value, and both state it as a contract: depth_of_field returns far_mm = inf beyond the hyperfocal distance (that is what the hyperfocal distance means), and gaussian_beam returns wavefront_radius_mm = inf at the waist (the radius of curvature of a plane wavefront). Both also return a finite companion (far_is_infinite / curvature_per_mm). Any other silent NaN/Inf is detected internally and raises ValueError — "float64 overflowed" and "the answer is infinite" are different claims, so the first is never returned wearing the face of the second.

• Size caps: generated grids are capped by optics.MAX_GRID (4096); supplied fields/PSFs/apertures by optics.MAX_FIELD_ELEMENTS (2^24); ABCD element chains by optics.MAX_SYSTEM_ELEMENTS (1024); Zernike by MAX_ZERNIKE_TERMS (512) / MAX_ZERNIKE_ORDER (40) / MAX_ZERNIKE_BASIS (2^25). This closes, fail-closed, the paths where a small argument triggers a huge internal allocation (measured: n_max=40 × 4096² needs 108 GB).

• Physically impossible states are refused too: a Stokes vector with degree of polarisation > 1, negative transmittance, negative intensity, and invalid Zernike indices such as n-|m| odd.

Detailed usage guide

• optics_imaging family guide

References (sample data, literature)

• Sample-data catalog (download URLs / licences) — 2-D uses skimage.data (BSD/public domain) plus synthetic images; 3-D lists download URLs for real data sources (Stanford, PDS, …).

• Operator provenance and references — the sources of the research/methods this op family came from.

• The canonical algorithm (author, year) and its uses are named in the family usage guide above.

Runnable examples (verified samples that actually call this op)

• poc_industrial_oct — py -3.11 examples/poc_industrial_oct.py

Ops the type connects to (they accept table as input)

abcd_matrix · wavefront_stats · sfr_from_edge · paraxial_trace · seidel_coefficients · spot_stats · tolerance_analysis · wavefront_from_opd

Same category (oct)

oct_design · oct_dispersion_broadening · oct_interferogram · oct_from_spectra · oct_k_linearize · oct_dispersion_estimate · oct_dispersion_compensate · oct_ascan


*Provenance: octscan.py — OPTICS operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*

© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.