Fundamental Aspects of Airy Disk Patterns
Abstract
This foundational knowledge article explains the basics of Airy disk patterns in microscopy. It covers how these patterns are generated from an infinitely small focused object point and, how they change with the numerical aperture and wavelength of the illumination. The article also simulates the approach of two Airy disk patterns and explains how to determine the resolving power of an objective lens.
Key Learnings:
- The size of the Airy disk pattern changes with the numerical aperture and wavelength of the illumination
- The resolving power of an objective lens can be determined by examining the size of the Airy disk pattern
- The Rayleigh criterion is the minimum distance between Airy disk patterns that can be resolved separately
Understanding the Symmetric Airy Disk Pattern and How it Changes in Size
The three-dimensional intensity distribution pattern originating from an infinitely small (sub-resolution) focused object point is symmetrically periodic along the optical z-axis of the microscope as well as radially around it. When this diffraction pattern is sectioned in the focal plane, it is observed as the classical two-dimensional intensity distribution known as the Airy disk pattern. This tutorial explores how the size of the Airy disk pattern changes with the numerical aperture (NA) of the objective and the wavelength of the illumination. It also simulates the close approach of two Airy disk patterns.