spectrometer 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.grating_dispersion(groove_density_per_mm=1200.0, wavelength_nm=550.0, incidence_deg=10.0, order=1, focal_length_mm=100.0, illuminated_width_mm=25.0) (to call the implementation directly, import gratingspec; gratingspec.grating_dispersion(groove_density_per_mm=1200.0, wavelength_nm=550.0, incidence_deg=10.0, order=1, focal_length_mm=100.0, illuminated_width_mm=25.0); from the registry, opsoptics.get("grating_dispersion"))
Solve the grating equation mλ = d(sin α + sin β) and tabulate angular and reciprocal linear dispersion, resolving power and the overlapping orders.
> The detailed description below is the original text — the summary and the headings are translated.
groove_density_per_mm: 溝の密度 G [本/mm]。溝の間隔は d = 1/G。
wavelength_nm: 波長 λ。incidence_deg: 入射角 α(法線から、Palmer の符号)。order: 次数 m(0 は拒否)。
focal_length_mm: カメラ(結像側)の焦点距離 f(線分散に使う)。illuminated_width_mm: 照らされた格子の幅 W(分散方向)。溝の数 N = W/d。
返り値(table):
• beta_deg —— 回折角 β。deviation_deg = α − β(入射光と回折光のなす角)。
• angular_dispersion_deg_per_nm / angular_dispersion_rad_per_nm —— dβ/dλ = m / (d cos β)。
• reciprocal_linear_dispersion_nm_per_mm —— P = d cos β / (|m| f)。
• anamorphic_magnification —— cos α / cos β(回折光と入射光のビーム幅の比)。
• grooves_illuminated / resolving_power (= |m| N) / resolving_power_max (= 2W/λ) / rayleigh_limit_nm (= λ / (|m| N)) / diffraction_fwhm_nm (= 0.8859 λ / (|m| N))。
• free_spectral_range_nm —— λ / |m|。littrow_deg —— この次数で α = β になる角(無ければ None)。
• orders —— 伝わる全次数の (m, β [deg]) の表。
• overlaps —— 同じ β へ出る他の次数の波長 (m', λ' = mλ/m')(迷光の次数。λ' は 50 nm 以上のみ)。
Raises ValueError: 0 次、伝わらない次数、非正の密度・波長・焦点距離・幅、|α| ≥ 90°。
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.
• 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.
• poc_spectrometer_illumination — py -3.11 examples/poc_spectrometer_illumination.py
table as input)abcd_matrix · wavefront_stats · sfr_from_edge · paraxial_trace · seidel_coefficients · spot_stats · tolerance_analysis · wavefront_from_opd
spectrometer)czerny_turner_design · spectrometer_bandpass · spectrometer_slit_image · spectrometer_spectrum
*Provenance: gratingspec.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.