Diffraction Limit Calculator

This calculator determines the diffraction limit (minimum resolvable feature size) based on the wavelength of light and the aperture size. It's commonly used in optics, microscopy, and photonics.

Input Parameters

Calculation Results

Calculation Formula

sin(θ) = 1.22 * (λ / D)

Where:
θ = half-angle of the diffraction limit
λ = wavelength of light in meters
D = aperture diameter in meters
The minimum resolvable feature size (R) is calculated as: R = 1.22 * (λ * D)

Diffraction Limit Calculator Calculator Usage Guide

Learn how to use the Diffraction Limit Calculator and its working principles

How to Use the Calculator

  1. Enter the wavelength of light in nanometers (nm). This is typically in the visible spectrum range of 400-700 nm, but can be for any light source.
  2. Enter the diameter of the aperture (e.g., lens diameter or sensor width) in millimeters (mm).
  3. Click the "Calculate" button to compute the minimum resolvable feature size.
  4. The result will be displayed in micrometers (µm), which is commonly used for measuring resolution in microscopy.

Working Principle

The diffraction limit is determined by the wavelength of light and the size of the aperture through which it passes. The formula used is based on the Airy disk diffraction pattern, which describes the minimum resolution limit for optical systems.

The formula is: R = 1.22 * (λ * D)

Where:

  • R is the minimum resolvable feature size
  • λ is the wavelength of light
  • D is the aperture diameter

This principle is fundamental in understanding the resolution limits of microscopes, telescopes, and other optical instruments.

Example

If you have a microscope with a light source of wavelength 550 nm and an aperture diameter of 5 mm, the minimum resolvable feature size would be:

R = 1.22 * (550e-9 m * 5e-3 m) = 3.35e-6 m = 3.35 µm