Airy Disk

The Airy disk is the diffraction pattern formed when light passes through a circular aperture. It consists of a bright central spot surrounded by concentric rings of decreasing intensity.

Mathematical Description

The intensity pattern is given by:

$$ I(\rho) \propto \left[\frac{J_1(2\pi\rho)}{\rho}\right]^2 $$

where $J_1$ is the first-order Bessel function and $\rho$ is the radial coordinate in the Fourier plane.

Physical Significance

• Describes the Fraunhofer diffraction pattern of a circular aperture
• Represents the point spread function of a circular lens
• Sets the fundamental limit of optical resolution

Related Terms

• Also called: Airy pattern, jinc function, sombrero function
• The central maximum contains approximately 84% of the total light energy