Aberrated Wavefront Phase
Corrected Wavefront
Aberrated PSF (blur)
Corrected PSF (sharp)
Turbulence
Strehl Ratio
—
1.0 = perfect optics
Zernike Coefficients
About
Atmospheric turbulence (described by Kolmogorov statistics, characterized by Fried parameter r₀) distorts incoming light wavefronts. Adaptive optics systems sense the aberration (via a Shack-Hartmann sensor) and correct it with a deformable mirror. The wavefront is decomposed into Zernike polynomials — tilt, defocus, astigmatism, coma, trefoil, etc. Higher modes need more actuators to correct.