Zernike Polynomial Calculator

Optics wavefront basis

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About Zernike Polynomial Calculator

A Zernike polynomial calculator computing Z_n^m(ρ,θ) = R_n^m(ρ)·cos/sin(mθ). Radial polynomial R_n^m via sum formula. Used in adaptive optics, corneal topography, aberration analysis, and telescope mirror characterization. Client-side.

Zernike Polynomial Calculator Features

  • Z_n^m value
  • R_n^m radial
  • Named aberrations
  • Mode table
  • OSA/ANSI index
Zernike polynomials: orthogonal polynomials on the unit disk. Z_n^m(ρ,θ) = R_n^m(ρ)·{cos(mθ), sin(mθ)}. Named modes: piston(Z₀⁰), tilt(Z₁¹), defocus(Z₂⁰), astigmatism(Z₂²), coma(Z₃¹), spherical aberration(Z₄⁰).

How to Use

Enter n, m, ρ, θ:

  • Value: Z_n^m(ρ,θ)
  • Radial: R_n^m(ρ)
  • Named: Aberration type

Optics Applications

Any wavefront on a circular aperture can be expanded: W(ρ,θ) = Σ a_{nm}Z_n^m(ρ,θ). Coefficients a_{nm} quantify aberrations. Adaptive optics corrects by applying opposite Zernike modes via deformable mirrors.

Named Aberrations

  • Z₀⁰: Piston (constant phase)
  • Z₁±¹: Tilt (beam direction)
  • Z₂⁰: Defocus
  • Z₂±²: Astigmatism
  • Z₃±¹: Coma
  • Z₄⁰: Spherical aberration

Step-by-Step Instructions

  1. 1Enter n and m.
  2. 2Enter ρ and θ.
  3. 3Compute Z_n^m.
  4. 4See aberration name.
  5. 5View mode table.

Zernike Polynomial Calculator — Frequently Asked Questions

Why are Zernike polynomials used in optics?+

They're the ONLY polynomials orthogonal on the unit disk (matching circular apertures). Each mode corresponds to a classical optical aberration. The coefficients are independent (orthogonality), making analysis clean and intuitive.

What's the relationship between n, m and aberration type?+

n = radial order (number of radial zeros + |m|). m = azimuthal frequency. n=0: piston. n=1: tilt/tip. n=2: defocus + astigmatism. n=3: coma + trefoil. n=4: spherical + secondary astigmatism + tetrafoil.

What are OSA and Noll indices?+

Instead of (n,m) pairs, single indices are used. OSA/ANSI: j = n(n+2+m)/2. Noll: different ordering optimized for atmospheric turbulence (lower Noll = more common in atmosphere). Both index the same polynomials differently.

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