quantum_noise_budget — OPTICS cavity 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.quantum_noise_budget(power_w: 'float' = 5200.0, mirror_mass_kg: 'float' = 40.0, length_m: 'float' = 3994.5, wavelength_nm: 'float' = 1064.0, *, itm_transmittance: 'float' = 0.014, f_min_hz: 'float' = 5.0, f_max_hz: 'float' = 5000.0, n_points: 'int' = 400) -> 'dict' (to call the implementation directly, import cavityoptics; cavityoptics.quantum_noise_budget(power_w: 'float' = 5200.0, mirror_mass_kg: 'float' = 40.0, length_m: 'float' = 3994.5, wavelength_nm: 'float' = 1064.0, *, itm_transmittance: 'float' = 0.014, f_min_hz: 'float' = 5.0, f_max_hz: 'float' = 5000.0, n_points: 'int' = 400) -> 'dict'; from the registry, opsoptics.get("quantum_noise_budget"))

Usage

Quantum noise of a conventional (no signal recycling) Fabry-Perot Michelson — shot, radiation pressure and the standard quantum limit.

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

Parameters

power_w : float

ビームスプリッタに入る光量 I₀ [W] (aLIGO 設計: 125 W × 出力再利用 ≈ 5.2 kW)。

mirror_mass_kg : float

試験質量 m [kg] (aLIGO 40 kg)。

length_m : float

腕の長さ L [m]。

wavelength_nm : float

波長 [nm]。

itm_transmittance : float

入力鏡の強度透過率 T(腕共振器の半値半幅 γ = Tc/4L [rad/s] を決める)。

f_min_hz, f_max_hz : float

周波数範囲(対数等間隔)。

n_points : int

点数。

Returns

dict

f_hz(配列)、振幅スペクトル密度 [1/√Hz] の配列 shot / radiation_pressure /

sql / total(√(S_shot + S_rp))、kappa(Kimble の K(Ω))、

スカラ gamma_rad_s / pole_hz / i_sql_w(I_SQL = mL²γ⁴/4ω₀)/

power_ratio = I₀/I_SQL / f_sql_touch_hz(K = 1 で総和が SQL に触れる周波数、

無ければ None)/ arm_power_w(循環光量 ≈ I₀·2/T の目安)。

Notes

Kimble, Levin, Matsko, Thorne & Vyatchanin, *Phys. Rev. D* 65, 022002 (2001) 式 (16)–(20):

h_SQL² = 8ħ/(mΩ²L²)、K = 2(I₀/I_SQL)γ⁴/(Ω²(γ²+Ω²))、S_shot = h_SQL²/2K、S_rp = K h_SQL²/2。門: S_shot·S_rp = h_SQL⁴/4(光量に依らない恒等式)、S_total ≥ h_SQL² で等号は K = 1 だけ。I₀ = I_SQL のとき K(γ) = 1 なので f_sql_touch_hz = γ/2π。aLIGO の設計感度は信号再利用と熱雑音を含むのでこの曲線とは形が違う —— examples/poc_gw_detector_pseudo_simulation.py が設計曲線と第二実装(gwinc)に当てる。

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_gw_detector_pseudo_simulation — py -3.11 examples/poc_gw_detector_pseudo_simulation.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 (cavity)

fabry_perot_response · cavity_strain_transfer · michelson_dc_readout · pdh_error_signal


*Provenance: cavityoptics.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.