lens_system — OPTICS design op

Data kinds: nonetable (an op determined by its arguments alone — it takes no image or data input)

Call: import raytrace; raytrace.lens_system(surfaces=None, stop=None, object_mm=inf, wavelength_um=0.58756, index_object=1.0, image_mm=None, field=None) (or opsoptics.get("lens_system"))

Usage

Build a validated sequential prescription (the `table` every other op consumes).

*surfaces* is a list; each entry is a dict ``{"R", "t", "n", "k", "ap",

"mirror", "decenter", "tilt", "asph"}` or a tuple (R, t, n[, k[, ap]])`:

• `R radius (mm, inf for flat), t` thickness to the next surface

(mm, the last one is the distance to the image plane when *image_mm* is

not given — use `None` to place the image at the paraxial focus),

`n medium after the surface (index, (nd, vd) or :func:glass`),

`k conic (default 0), ap semi-aperture in mm (default None` =

unlimited), `mirror bool, decenter (dx, dy) mm, tilt`

`(ax, ay) degrees about x and y, asph` even aspheric coefficients

`(A4, A6, A8, …)` in mm⁻³, mm⁻⁵, … (default none = pure conic).

• *stop*: index of the aperture-stop surface (default: the first surface).

The stop's `ap` is the stop radius (required unless every surface has

one, in which case the smallest is used).

• *object_mm*: distance from the first vertex to the object (`inf` for a

collimated object); *index_object*: index of object space.

• *field*: default field for the analysis ops — degrees (infinite object)

or object height in mm (finite object). Default 0 (on axis).

Default (no *surfaces*): a plano-convex BK7 singlet, `f ≈ 100 mm`,

`f/4`, stop at the first surface — a sensible starting point for the

examples and for the no-argument registry call.

Returns a plain dict (JSON-friendly) — pass it to the other functions.

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)

lens_calibration_loop_demopy -3.11 examples/lens_calibration_loop_demo.py

lens_defect_dataset_demopy -3.11 examples/lens_defect_dataset_demo.py

lens_design_demopy -3.11 examples/lens_design_demo.py

lens_optimize_demopy -3.11 examples/lens_optimize_demo.py

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

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

Same category (design)

thick_lens · glass · example_system · glass_catalog · sellmeier · paraxial_trace · seidel_coefficients · spot_stats


*Provenance: raytrace.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.